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Home , Firestorm, Painted Cave Fire, Santa Barbara Channel, San Marcos Pass, Simoom, Sundowner winds

NOAA TECHNICAL MEMORANDUM NWSWR-240

DOWNSLOPE OF SANTA BARBARA,

)

Gary Ryan . NEXRAD Service Forecast Office Oxnard, California

July 1996

) U.S. DEPARTMENT OF National Oceanic and National Weather COMMERCE I Abnospherie Administration I Service WdNams, Jr., May 1972. (COM 72 10701) 78 Monttly~ OWts of the BehiMor of and l.Qw Slratus at I.DI Angeles International Airport Donald M. , July 1972. (COM 72 11140) • n A Study of Radar Echo Distribution in Arilona During July and Augull John E. Halel, Jr., July 1972. (COM 7211136) 78 Forecaoting at BakeBiield, California, Uling Pressure Gredient Vectors. Earl T. Rlddiough, July 1972. (COM 7211148) 79 of Stockton, Cafdornia. Robert C. Nelson, July 1972. (COM 72 10920) NOAA TECHNICAL MEMORANDA 60 Estimation of Number of Days Abow or Below Selected Temperotures. Clarence M. Sakamoto, October 1972. (COM 72 10021) National Weather Service, Western Region Subseries 81 An Aid to< Forecasting Summer Maximum Temperaturn at Seattle, Washington. Edgar G. Johnson, Ncwwmber 1972. (COM 7310150) The Nolicnol S.fllice (NWS) Westem Region (WR) SUbseries pnMdes an inlonnal medium to< 82 Flash Flood Forecasting and Warning Program in the Weslem Region. Philip Winiams. Jr., the documentationw- and quick dissemination of results not appropriate, or not yet ready, tor lonnal O..WL Glem, and Roland L Raetz, December 1972. (Revised March 1978). (COM 73 10251) publication. The series is used to report on wot1t in progress, to describe technical ptocedures and 63 A~ of Manual and Semiautomatic Methods ol Digitiling Analog Records. G lenn proclices, or to relote progress to a limited audience. Thew Technical Memoranda woll report on E. Rasch, March 1973. (COM 73 10669) irwnliga1iors delolod prirnonly to regionol and local problems of interest mainly to personnel, and hence 66 Condticnal Pnlbatiitiesfao Sequence• of Wet Days at Phoenix. Arilona. Paul C. Kangieser, June will not be w;dely distributed. 1973. (COM 73 1 1 284) 67 A Refinement of the Use of K.Valuos in Forecasting in Washington and Otegon. Papers 1 to 25 are in tho former series, ESSA Technical Memoranda, Westem Region Technical RobertY.G. Lee, June 1973. (COM 7311276) Memoranda (WRTM); papers 24 to 59 are in the lonner series, ESSA Technical Memoranda, Weather 89 Objective Forecast Precipitation Over the Westem Region of the Un~ed States. JuliaN. Paegle Bureau Technical Memorondo (WBTM). Beginning with 60, the papers are part of the series, NOAA and Lany P. Kierultt, September 1973. (COM 731194613AS) Technical Memoranda foloNS. Out.of·print memoranda are not listed. 91 Arilona "EddY" Tornadoes. RobertS. Ingram, October 1973. (COM 73 10465) 92 Management in the Willamette Valley. Eart M. Bates, May 1974. (COM 74 112ntAS) Papers 2 to 22. except tor 5 (revised edition), are available from the National Weather S.M<:e Westem 93 An Operalional Evaluotion of SQO.mb Type Regression Equationa. Al111ander E. MacDonald, June Regiol, SeMces OMsion, 125 South State Street· Rm 1210. San Lake City, Lnah 84133-1102. Scion1tic 1974. (COM 74 11407/AS) Paper 5 (revised edition), and all others beginning with 25 are available from the National Technical 94 Cond:lia>al Pnlbability at Visibility Less than One-HaH Mile in Radiation Fog at Fresno, California. Information s.Mce, U.S. Department of Commerce, Sills Building, 5235 Port Royal Road, Springfield, John D. Thomas, August 1974. (COM 74 11555/AS) -· Vorgno 22181. Prioes """'lor al paper copies; microfiche are $3.50. Otder by accession number"-" 95 amate of Aagstatr, Arilona. Paul W. Sorenson, and updated by Reginald W . Preston, January in parorrtheses at end of each entry. 1987. (P867 143160/AS) 96 Mop type Precipitation Probabilities to< the Westem Region. Glenn E. Raoch and Alexandot E. ESSA Technical Memoranda (WRTMJ MacDonald, February 1975. (COM 7510428/AS) ~·, 07 ea.tern Pacific Cut.otl Low of Apri121·28. 1974. WiUiam J. Alder and George R Millot, January 2 Climatological Precipitation Probabilities. Compiled by Lucianna Miller, December 1965. 1076. (PB 250 71 1/AS) 3 Westem Region Pro- and Post·FP.J Program, December 1, 1965, to February 20, 1968. Edward 98 Study on aSigr11icant Precipitation Episode in Westem United States. 1111 S. Brennot, Apri11976. D. Diemer, March 1968. (COM 75 10719/AS) 5 Slalion OeocriptjonsofLocal Effects on SynoplicWeather PatlemL Philip W iHiams, Jr., April 1968 1111 A Study of Flash Aocd SUsceptibility·A Balin in Southam Arizona. Gerald W illiams, August 1975. (Revised N

DOWNSLOPE WINDS OF SANTA BARBARA, CALIFORNIA

Gary Ryan NEXRAD Weather Service Forecast Office Oxnard, California

July 1996

UNITED STATES National Oceanic and National Weather Service DEPARTMENT OF COMMERCE Atmospheric Administration Elbert W. Friday, Jr., Assistant Mickey Kantor, Secretary D. James Baker, Under Secretary Administrator for Weather Services and Administrator This publication has been reviewed and is approved for publication by Scientific Services Division, Western Region

gj_d_" Delain A. Edman, Chief Scientific Services Division Salt Lake City, Utah

iii TABLE OF CONTENTS

TITLE PAGE

Table of Contents ...... iv

Figures and Tables ...... v

Abstract ...... 1

I. Introduction ...... 1

II. Section One:

A Santa Barbara Sundowners: An Historical Perspective ...... 2

B. Public Safety, , and Painted Cave ...... 6

Ill. Section Two:

Downslope Wind Mechanisms ...... 9

IV. Section Three:

Investigation of Santa Barbara Downslope Winds ...... 11

A Physical Geography ...... 11 B. S~udy M~thod, Data Analysis and Reduction' ...... 12 C. D1scuss1on ...... 13 1. Non-Sundowner Warming ...... 13 2. Sundowner Wind Circulation ...... 14 3. Severe or Category 3 Sundowners ...... 15 D. Forecasting Sundowners ...... 17 E. Guidelines for Forecasters ...... 18

V. Conclusion ...... 20

VI . References ...... 20

VII. Acknowledgments ...... 21

iv FIGURES AND TABLES

FIGURES PAGE

1. Map of Southeastern Santa Barbara County ...... 23 2. Santa Barbara Morning Press Feature Story, 6/18/17 ...... 24 3. George Russell's Weather Log, June 1917 ...... 25 4. Fire Closes In On Santa Barbara Residence ...... 26 5. Rel ief Map of Santa Barbara County ...... 27 6. Santa Barbara County Profile ...... 28 7. Santa Barbara Area Weather Reporting Sites, 3/95 ...... 29 ?a. Area of Strongest ...... 30 8. Downslope Wind Profile, June 1-7 1994 ...... 32 9. Severe Downslope Wind Map Type (850mb) 6/27/90 ...... 33 10. Severe Downslope Wind Map Type (500mb) 6/27/90 ...... 34 11 . Vandenberg AFB UA Sounding 6/27/90 ...... 35 12. Projected Isentropic Flow at Santa Barbara 6/27/90 ...... 36 13. Maria Ygnacio Ridge Following ...... 37 14. Maria Ygnacio Ridge Sensor SBCFCD Sensor Array ...... 37 15. VBG NEXRAD View, Initial Phase, Downslope Wind Event ...... 38 16. VBG NEXRAD View, Mature Phase, Downslope Wind Event ...... 39

TABLE PAGE

I. Significant Warming Event Categories ...... 31 II. Means for Category 0 Events ...... 40 Ill. Means for Category 1 Events ...... 41 IV. Means for Category 2 Events ...... 42 V. Means for Category 3 Events ...... 43 VI. Combined Means for All SWEs ...... 44

v DOWNSLOPE WINDS OF SANTA BARBARA, CALIFORNIA

Gary Ryan NWSFO Oxnard, CA

ABSTRACT

Warming, downslope winds from the in Southern California can translate to gusty surface winds in the vicinity of Santa Barbara. These winds, called "sundowners," have many of the same characteristics common to downslope winds found elsewhere in the world. Sundowners can be strong enough to cause considerable damage and are sometimes accompanied by very high temperatures. This study provides historical information from several severe sundowner events which affected the Santa Barbara area-­ including accounts of the incidents of 1859, 1917, and 1990--and addresses public safety concerns relative to these episodes. The paper also discusses the dynamics of downslope winds, establishes a categorical rating for sundowner episodes, and offers empirical rules for identifying and forecasting the sundowner regime.

I. INTRODUCTION along the southern slopes of the Santa Ynez Mountains accompanied by Approximately 150 kilometers northwest extremely hot temperatures at Santa of Los Angeles, along the Pacific coast Barbara (>1 04 oF). and beneath the ridges and canyons of the Santa Ynez Mountains, lies the city of Sundowners, like most downslope winds, Santa Barbara (1993 population 87,500). vary in duration and intensity. Light Due to the proximity of the mountains, this sundowners cause irregular rises in area occasionally experiences warm, temperature and accompanying gentle downslope winds--known locally as offshore breezes at Santa Barbara. "sundowners." Strong sundowners, occurring two or three times a year, coincide with sharp Sundowners, while similar in some rises in temperature and local force respects, are independent of which can cause damage to winds and much smaller in scale. structures or vehicles. On rare occasions, Sundowners receive their name from the about once every five or ten years, a wind's predominant time of occurrence­ severe sundowner develops producing the late afternoon and evening hours. hot, damaging winds along the south side The exact origin of the term "sundowner" of the Santa Ynez Mountains and the is unknown; but the name dates from adjacent littoral. about the middle of the 20th century. Bosart (1983) and Clark and Dembek Urban wildfires, fanned by the high wi nds, ( 1991 ), in their studies of the Catalina pose the most significant hazard Eddy, noted afternoon downslope winds associated with strong to severe

1 sundowner windstorms. In the past two "severe" event is discussed elsewhere in decades, four major wildfires have this paper: occurred during such sundowner episodes. The mosf recent and damaging 1. June17, 1859 of these events, the Painted Cave Fire, 2. September 21-24 1885 ( at occurred on June 27, 1990, burning 4900 Mission Creek) acres and destroying over 500 structures. 3. July 27, 1889 The fire raced along th e western 4. July 2-3, 1907 periphery of the city of Santa Barbara, 5. June 15-17, 1917 (numerous spread by winds gusting to over 60 mph wildfires) (27 m/s). 6. July 12-13, 1925 (wildfire near city) 7. July 29, 1930 This paper discusses the sundowner wind 8. June 30-July 1, 1937 phenomenon, establishes a categorical 9. September 22, 1964 (Coyote Fire) rating, and offers empirical rules for 10 July 25-26, 1977 (Sycamore Fire) identifying and forecasting sundowner 11 . July 15, 1978 wind events. While this study is limited to 12. September 18, 1979 (Eagle Canyon downslope winds in the vicinity of Santa Fire) Barbara, it may have applications 13. August30, 1984 elsewhere along the south-facing coast of 14. July 2, 1985 (Wheeler Fire) Santa Barbara County. 15. June 25-27, 1990 (Painted Cave Fire)

II. SECTION ONE June 17, 1859 A. SANTA BARBARA SUNDOWNERS, Historical texts describe a phenomenal A HISTORICAL PERSPECTIVE sundowner which struck the city of Santa Barbara on Friday, June 17, 1859. Historically, severe sundowner Contemporary accounts termed the · windstorms · have occurred only downslope windstorm a "" or occasionally in the Santa Barbara area. "simeon"- from the "samum" A survey of these events is important for which means a "hot and violent dust­ understanding their threat to public safety. laden desert wind." During this event, very hot north to northwest winds caused The following is a chronological listing of a hellish duststorm that frightened the the most notable severe sundowner inhabitants of the city. There are two events which have occurred since 1850, accounts of this windstorm. George the year Santa Barbara came under Davidson, an assistant in the U.S. Coast United States authority. The apparent Survey in California, wrote an account of increased frequency of these events in the sundowner which was published in the late twentieth century is likely due to the Coast Pilot in 1869: improved observing and reporting techniques, rather than to any climatological change. The criteria for a

2 THE SIMOOM Fortunately, another account of the 1859 windstorm was preserved by the Santa The only instance of the simoom on this Barbara Morning Press, in 1907, when it coast, mentioned either in its history or quoted an 1876 volume on The History traditions, was that occurring at Santa and Resources of Santa Barbara: Barbara, on Friday, the 17th of June, 1859. The temperature during the On the 17th day of June, 1859, a hot morning was between 75 o and 80 °, and wind, like a , visited the city of gradually and regularly increased until Santa Barbara. The wind was from the about one o'clock p.m., when a blast of northwest and blew furiously, with a hot air from the northwest swept suddenly dense of dust. The temperature over the town and struck the inhabitants rose to 136 Fahrenheit's scale. It with terror. It was quickly followed by - commenced blowing about noon and others. At two o'clock the thermometer continued until about half past three in the exposed to the air rose to 133 °, and afternoon. Birds, rabbits, and tender continued at or near that point for nearly lambs were killed; the leaves on the side three hours, whilst the burning wind toward the wind were scorched and died, raised dense clouds of impalpable dust. and some fruit was blasted. No human being could withstand the heat. All betook themselves to their dwellings Although there is little doubt that a severe and carefully closed every door and downslope wind and dust occurred window. The thick adobe walls would in Santa Barbara on June 17, 1859, the have required days to have become reported temperature reading of 136°F warmed, and were consequently an (57.8°C) is highly suspect. If true, that admirable protection. Calves, rabbits, reading would tie the record high birds, &c., were killed; trees were temperature for the Earth set in Libya in blighted; fruit was blasted and fell to the 1922. ground, burned only on one side; and gardens were ruined. At five o'clock the While the two accounts are fairly thermometer fell to 122 °, and at seven it consistent, and ambient surface stood at 77 °. A fisherman, in the channel temperatures in the 130s are theoretically in an open boat, came back with his arms possible within the sundowner regime, badly blistered. another explanation for the reported record-setting temperature is more likely. Davidson's secondary account of the At the time of these accounts, 1859 simoom was embellished by a local thermometers were not always shaded historian, Walker A. Tompkins, in his book from the sun. Significantly, in the Goleta, the Good Land (1962). It was Davidson account, the phrase Tompkins who placed a U.S. Coast "thermometer exposed to the air" could Survey ship in Santa Barbara Channel to refer to a thermometer hanging in direct document what he claimed was a record sunlight. Then again, wind-blown dust-­ high temperature for the United States. mentioned in all accounts- may have His other liberties with the Davidson obscured the sky during that afternoon. account cast doubt on this claimed Thus, an "exposed" thermometer might record. not have been exposed to full direct sunlight.

3 Weather observation techniques were not sundowner wind within the city "came in standardized by the United States hot puffs and gusts from all directions." It government until about 1870, and official added: temperature records were not taken at Santa Barbara until1883. Since then, the The only time Santa Barbara has suffered official maximum recorded temperature at any such visitation is when the Santa Santa Barbara has been 115 oF. The Ynez Mountains are aflame with forest reported temperatures of 136 oF and . Colonel Slosson reported last night 133 oF, contained in the 1859 accounts, that the ranges were free from fire, so are well above the records within the other causes must be responsible for the official Santa Barbara climatological excessive . record. Therefore, the alleged 1859 maximum temperatures are very likely New weather observer George W. Russell inaccurate and should not be considered recorded a high temperature of 1 08 o on official. July 3rd, which still stands as the all-time record high temperature for the month of September 21-24 1885 July for the city of Santa Barbara. Three days of hot downslope winds culminated on September 24th when the June 15-17, 1917 temperature peaked at 108° at 4 pm. By The most severe downslope wind episode 8 pm, it was still 102°. A fire which had to occur thus far in the twentieth century started on the north side of the Santa struck Santa Barbara on Saturday night Ynez Mountain ridge line was carried and Sunday, June 16-17, 1917. Fires rapidly from the ridge crest into the burned throughout the district, whipped by Mission Creek district of Santa Barbara. the strong winds. The situation was The Santa Barbara Morning Press especially critical at nearby Carpinteria, reported that where residents carried their belongings to the beaches to avoid an advancing No Fourth of July celebration could . In Santa Barbara, strong compare with this. The fire came down winds created a duststorm "such as had the mountainside with the speed of a never been known in this city before." horse; and soon the mountain seemed a (Fig. 2) The winds blew at gale force from vast furnace painting the heavens with its 6 pm Saturday until 2 am on Sunday, and lurid crimson hues... The awful roar of the later on Sunday from 2 pm to 1 0 pm. On voracious element, plainly heard a Sunday afternoon, June 17th, the official distance of five miles, the sheet of temperature at Santa Barbara reached its sweeping along the mountainside and all-time modern record (since 1883) of leaping high into the air, the immense 115°, as the four-day heat wave peaked. volumes of black smoke rolling skyward, Cooperative weather observer George W. rendered the scene grand and appalling. Russell entered the following remarks on the official record (Fig. 3): July 2-3, 1907 The Santa Barbara Morning Press The hottest day ever recorded on the reported that the city temperature was 17th. A hot wind during night 16th with 88 o at midnight. It noted that the velocity of 35 to 45 miles per hour,

4 damaged fruit and other trees. Nuts are and reached storm force (55 mph) by 8:20 damaged, beans seem to have escaped. pm. Reported winds of 60 to 70 mph were accompanied by temperatures in July 12-14, 1925 excess of 1ooo. In the event, a young At 10:45 pm on July 12th, gale force man was flying a four-foot kite in a canyon winds swept down from Mission Ridge above Santa Barbara when the kite got into the city of Santa Barbara. A fire tangled in power lines, causing a shower started and spread quickly toward the city. of sparks. This initiated a fierce wind­ The fire was suppressed by a company of driven fire which raced down Sycamore Marines, on duty at Santa Barbara after Canyon into Santa Barbara and an which had occurred a few Montecito, destroying 195 homes within days earlier. Reliable estimates placed eight hours. wind speeds at 40 to 60 mph, and accompanying temperatures were July 15, 1978 measured in excess of 1oo o. According Temperatures at Santa Barbara and to the Santa Barbara Morning Press: Montecito reached 106 degrees with a relative humidity of 24 percent. In the It was the first time in many years, old foothills, upper Mission Canyon reported residents said, that a wind had blown from 1 00 o and San Roque Canyon 102 o. that direction. It was what old residents Santa Barbara Harbor noted offshore call "a Santa Ana" and blew hot off the winds gusting to 30 knots between 4:00 desert beyond the mountains almost all and 6:00 pm. The California Highway day... The heavy windstorm damaged Patrol reported that a large cabover many trees in the city, tearing down a few camper overturned on Highway 101 at ... and splitting limbs off in all Gaviota. sections of the city. September 18, 1979 July 29, 1930 Downslope canyon winds of 40 mph, Official cooperative weather observer Ella accompanied by temperatures of more M. Russell logged high temperatures of than 1oo o, pushed a major brush fire from 1oo o on July 29th and 30th in the Oak Eagle Canyon southward across the 101 Park section of Santa Barbara. She wrote Freeway almost to the ocean. Eagle that there had been a "very strong north Canyon is located just west of Santa wind on the 29th from 3 a.m. until Barbara. midnight." August 30, 1984 June 30-July 1, 1937 The FAA reported a maximum The high temperature on June 30 reached temperature of 101 o (a record for that 101 o between 4:00 and 4:30 pm. On July date) at Santa Barbara Airport. The 1 the maximum temperature reached following notation was made in a log of 108° at 2 pm and was accompanied by a recent sundowner activity. The log was "firey [sic] northeast wind." kept by Santa Barbara meteorologist Chris Crabtree: July 26, 1977 Downslope winds began about 7:30 pm

5 Late am NW-N/25+ in Goleta. on the south side of San Marcos Pass, Temperatures abov~ 100 o at Santa downslope winds were strong and erratic. Barbara. Point Conception NW 60. Due At La Cumbre and State Streets in Santa to passing short wave kicked out of cutoff Barbara, winds gusted to 60 mph; while at low offshore. SMX-SBA 6 mb!, 5 mb at Santa Barbara Airport, the winds peaked 2000. at only 30 mph at 3:48 pm PDT. The strongest winds were reported near This pressure gradient entry is significant Tucker's Grove, at the base of Old San in the context of sundowner research Marcos Road, where wind speeds conducted since 1950 and noted within reached 80 mph. this paper. A description of the Painted Cave Fire June 27, 1990 and associated meteorological conditions A three-day heat wave at Santa Barbara is contained in the following section. culminated on Wednesday, June 27th, with an epic sundowner windstorm. B. PUBLIC SAFETY, WILDFIRESs AND Meteorological parameters from that day PAINTED CAVE. have been well-documented relative to previous severe sundowner events. Downslope windstorms in the Santa Barbara area pose a serious hazard to Temperatures at Santa Barbara reached public safety on at least two fronts: the 90s by mid-morning, and peaked at increased fire danger and a potential 1ago at Santa Barbara Airport at 1:30 pm threat to ground and air transportation. PDT. Maximum reported temperatures Since 1950, five of seven severe along the Santa Barbara coastal strip downslope windstorms have fanned ranged from 103 o at the El Estero Water wildfires in the immediate vicinity of the Treatment Plant near lower State Street in city of Santa Barbara. These sometimes Santa Barbara to 116° at El Capitan tragic and invariably expensive fires Beach 11 miles west of Santa Barbara resulted in significant disruption to normal Airport. Ambient temperatures near the activity and commerce in the area. Other fire along Old San Marcos Road were areas of concern, including public health, estimated to have been nearly 150° F agriculture, and marine, are significant but (Ford, 1991 and Lebonville, personal beyond the scope of this study. communication, 1994). The fire danger associated with Winds at 5,000 feet over Santa Barbara downslope wind events is well were from the north-northwest at about 23 documented. While all wildfires in the mph. At normally windy Point vicinity of Santa Barbara are not driven by Conception, surface winds were sundowner winds-- for example, the northwest up to 53 mph and temperatures Refugio Fire of 1955--most major fires were in the upper 50s. At the summit of affecting the Santa Barbara area appear San Marcos Pass, where te.mperatures to be spread by downslope wind remained in the 80s throughout the conditions. sundowner event, winds were also from the northwest at 10 to 20 mph. However,

6 Historical evidence indicates that fires destructive than those which once have periodically burned over the Santa occurred in prehistoric times. Barbara district for a very long time. Layers of graded silt in the channel near Fires associated with downslope wind Santa Barbara contain charcoal from episodes pose a unique danger for fire wildfires that occurred two million years fighters. According to Fritz Cahill, former ago (Gomes, 1993). Core samples taken U.S. Forest Service Officer for the from the channel indicate that large Los Padres National Forest, the problem wildfires, presumably -caused, with sundowner-generated fires is that occurred in the district on an average of they run downhill, not uphill like normal once every 66 years (Ford, 1991 ). With fires. Therefore, they can catch even a the coming of man, fire became an even veteran fire fighter off guard. more frequent intruder. Wildland burning was a frequent practice of the Chumash The June 27, 1990 fire, called "Painted Indians, whose pre-European settlement Cave" after a prehistoric Native American of Syukhtun stretched from Goleta to landmark near the fire's origin, was the Carpinteria. Ford quotes an early worst of all the sundowner blazes. This Spanish governor at Santa Barbara, Jose -caused was the focus of Joaquin de Arrillaga, who forbade the considerable national media attention. practice of setting wildland fires in 1793: The Forest Service had issued a "Red Flag Alert" for extreme fire danger on With attention to the widespread damage June 27th, which was the third day of which results to the public from the downslope wind conditions in Santa burning of fields, customary up to now Barbara. Fire protection crews, patrolling along both Christian and Gentile Indians the entire district, spotted the first smoke in this country, whose childishness has early after ignition, at 6:02 pm PDT. The been unduly tolerated, and as a origin of the fire was at the intersection of consequence of various complaints that I Old San Marcos Road and Highway 154. have had of such abuse, I see myself The ambient temperature at the fire's required to have the foresight to prohibit point of origin was 96°, with relative for the future ... all kinds of burning, not humidity at 10% and winds from the only in the vicinity of towns but even at northwest at 12 to 20 mph (Gomes). the most remote distances ... The fire gathered momentum quickly in Fire suppression efforts have intensified the steeply sloped (40-60%) terrain. The during the past 200 years, co incident with foliage, consisting mostly of dense, oily large increases in urban and suburban chaparral, had not burned since the populations. Ford points out that. .. 1890s. The front climbed 40 to 70 After almost two hundred years of efforts feet high and temperatures in the vicinity to the contrary, the policy of excluding fire of the front were estimated to have from the hills has done the opposite of reached 3000°F. By 6:45 pm, the fire what has been desired; there are far front had already advanced two miles fewer small fires, but those which do from the point of origin. Downslope winds occur burn even larger, and are more increased to about 60 mph, pushing the wall of flame downhill more rapidly. Due

7 to severe turbulence over the fire caused but they predominantly traveled by the high winds and thermals, air tanker southeast, which is downhill, and once support for fire suppression was not they got down to the [coastal strip] they available until after 7: 00pm. tended to fan out a little bit, but generally they continued to travel in a south­ Before the fire was extinguished, it had easterly direction. The smoke was an taken one Iife and consumed over 4900 excellent indicator of airflow around the acres. It stretched over five miles from fire. San Marcos Pass across State Street at the edge of Santa Barbara and across the The winds are one of the major problems 101 Freeway, a 340 foot wide man-made during a fire as they blow whole burning firebreak. In doing so, it completely cut branches and large flaming embers off transportation through the district. around and the fire spreads very rapidly. Property losses were extensive with over The fire burns so intense and so hot that 500 structures destroyed, valued at $290 it sucks the away and pulls more million. Videotape from the fire showed air towards it.. . [the] heat tends to dry ash falling on Old San Marcos Road like everything out in front of the fire so things some bizarre June snowfall. literally explode; buildings, trees, cars, anything can explode into flames ... As bad as the Painted Cave fire was in terms of destructiveness, it came very At one point during the , Jay close to being a lot worse. Stan Dumas, Lebonville climbed up onto his friend's Assistant Fire ·Chief for the City of Santa roof with a garden hose, in an Barbara, recalled that the fire raced to unsuccessful attempt to save the house: State Street and burned to within yards of a commercial chlorine supply tank At times gusts in excess of fifty miles per containing up to 5000 gallons of the hour would push us over [when we were] chemical. Fourteen heroic fire fighters on the roof, our footing became hard to kept the tank from exploding. Dumas said keep. I continued to spray the roof, that the ch lorine ... "would have gone ourselves and a nearby hedge with water through [the] Hope Ranch [district]. It while my friend's family tried to get as would have been a real ki ller." much as they could out of the house .. .[Fig . 4] Santa Barbara area resident Jay Lebonville, a National Weather Service Even without a fire, strong downslope storm spotter, described (personal winds associated with sundowners can communication, 1994) the winds during greatly impact local transportation due to the Painted Cave Fire in his report of the the high velocities attained. Trucks, vans, event: and other high profile vehicles may be affected by high winds along Highway 154 You could see the smoke was coming south of San Marcos Pass and on some down the hill and it was actually dropping sections of the 10.1 Freeway near Santa in elevation before heading out to sea and Barbara. The California Highway Patrol rising as it left the coast. The winds were frequently issues a "high wind warning" gusty and would go in different directions, for the areas affected, based on an

8 officer's subjective report of an winds in particular. The reader may find occurrence already in progress. this review to be helpful before considering specific analyses of Downslope winds are of great concern to occurrences of Santa Barbara's aviation interests in Santa Barbara. The sundowner winds. Santa Barbara FAA Flight Service Station documented three aircraft mishaps at or There has been a considerable amount of near the Santa Barbara Airport during scientific research into downslope wind sundowner activity occurring between phenomena, dating back to at least 1885. 1985 and 1991 . Pilots flying into the area Modern theories advanced since World during episodes of downslope winds must War II have been amplified by be aware of the low-level wind shear atmospheric modeling and complex hazard and strong downdrafts which can computer techniques. A few standard occur on the lee side of the Santa Ynez sources are listed in the "references" Mountains. section of this report, and an excellent overview was presented by Keith Meier One veteran Santa Maria pilot, who has ( 1994) in a National Weather Service flown the Santa Maria to Santa Barbara pub Iication . route during several sundowner events, described the flights as being "scary." To a considerable extent, investigations Flying over the Santa Ynez Mountain into fluid dynamics have been vigorously ridge line and descending to around 5000 adapted by meteorologists to explain feet, the aircraft can be forced downward downslope wind mechanics. Jakob within the downslope wind regime. The Bernoulli's equation relating fluid aircraft is virtually out of control until pressures and velocities has been used in stabilization can be attained, generally discussions of wind channeling through about 500 feet over the Santa Barbara topographic gaps and canyons. But the runway complex. "Bernoulli effect" is not a predictor: the equation can't be used to model flow During sundowner wind occurrences, low­ through a hydraulic jump. level wind shear poses a significant hazard; runway winds vary rapidly in both Hydraulic flow models used in fluid speed and direction. During one recent dynamics to describe open channel flow episode, the FAA at Santa Barbara over a barrier were adapted by Long Airport issued several "urgent" pilot (1953) in a mainly successful application reports when local air traffic reported to atmospheric criteria. Horel ( 1992) severe updrafts and downdrafts. states that recent investigation indicates that much of observed downslope wind phenomena can be explained by utilizing Ill. SECTION TWO · DOWNSLOPE the "hydraulic jump" concept. This WIND MECHANISMS conclusion is supported by Jim Goodridge, an engineer and former This section reviews some basic theories California state climatologist, who has regarding the mechanics of downslope intensively studied downslope wind winds in general, and warming (foehn) events (personal communication, 1994 ).

9 Long's hydraulic flow model described the in wave and energy transport. These movement of a fluid streaming over the authors did not discard hydraulic jump top of a barrier, regarding velocities, layer theory; however, they believed that thicknesses (in a two-layer model), and hydraulic jump models were incomplete the formation of a breaking wave or and that the results may be misleading. "jump" on the lee side of the barrier. The efficacy of Long's work was in its Klemp and Lilly argued the importance of hardware modeling and in its linear strong static stability layers to reflect equation work, which factored out small energy. They concluded that when a low­ perturbations within the flow. level, stable layer and the less stable layer above have optimum thicknesses, Hydraulic jump representations employed reflectivity in the lower atmosphere can the use of the Froude number (Fr), named produce mountain wave regimes to for British naval architect William Froude. heights of several kilometers. The Fr expresses the ratio between authors devised a scheme to estimate gravitational and inertial forces, and maximum perturbation surface ve.locities, serves as a flow indicator. Specifically, Fr based upon the height of the inversion describes the nature of the flow layer. ( subcritical or supercritical), thus indicating whether wave propagation can Clark and Peltier described upward progress upstream, and marking the propagating gravity waves, which "break" location of the breaking regime (at Fr=1 ). and create what they termed a "wave­ Channel or terrain slope is an important induced critical level." . This level, consideration here, since gravity may characterized by wind reversal and accelerate the flow to supercritical values. significant mixing, reflects large amplitude "Hydraulic jump" may be satisfactory for waves back toward the surface. modeling the majority of parameters in downslope wind events; however, the Investigations are ongoing with respect to atmosphere cannot be approximated in a the vertically propagating mountain wave. free-surface or rigid form where no energy Wurtele (personal communication, 1993) can be transported vertically through the underlined the uncertainty inherent in upper boundary of the model. Contrary to current understanding of mountain wave hydraulic jump theory, in the atmosphere processes: waves can propagate vertically as well as horizontally. In severe downslope wind Studies of the critical layer have for the episodes, vertical wave propagation might most part been limited to the impact of a be a critical element. single monochromatic wave, and when the is forced over a Although different theoretically, two continuous spectrum, the question is still classic studies have underlined the pretty much open. Clark, Peltier, and Co. importance of vertical wave propagation have speculated on the result when the in downslope wind occurrences. The wind reversal is in the , that analyses of Klemp and Lilly (1975) and is, when the disturbance is forced upward Clark and Peltier (1977) agree that the through a with increasing entire troposphere can become involved wind. They suggest some sort of

10 resonance, but their results are not at all Horel, Wurtele and others have complete or conclusive. suggested that a reversal of zonal flow above the ridge line crest can be a Due to changing system dynamics and primary factor, both theoretically and complex terrain, downslope wind practically, in the initialization of strong episodes simultaneously combine the downslope windstorms. characteristics of Bernoulli effect, hydraulic jump, and vertically propagating Yet another, perhaps more obvious, mountain waves. Hence, the difficulty in condition for downslope wind generation creating one satisfactory model of a is noted by Durran. He states that the downslope wind occurrence. The synoptic-scale pressure gradient is accurate forecast of downslope wind important in that parameters, such as timing, period, intensity, and focus, is not presently ... mountain waves generate a mesoscale possible. Projecting wave celerity within pressure distribution with high pressure a vertically propagating regime is upstream of the crest and low pressure in especially difficult. It is no wonder that the lee. Strong downslope winds are downslope wind profiles and associated more likely to develop when the synoptic­ mesoscale patterns are largely scale pressure gradient is in phase with inscrutable, especially given the rapidity the wave-induced pressure gradient. with which the dynamics can change. A basic understanding of some principles While the precise forecasting of of flow dynamics and a consideration of downslope wind parameters remains atmospheric factors as outlined above, elusive, there are specific features that provide a good backdrop for an analysis can be used successfully to predict the of Santa Barbara's sundowner w•nds. development of mesoscale downslope wind events. Durran (1986) lists three conditions set by Queney in 1960 in which IV. SECTION THREE - INVESTIGATION strong lee waves are likely to occur: OF SANTA BARBARA DOWNSLOPE WINDS ( 1 ) The mountain barrier in question has a steep lee slope. A. PHYSICAL GEOGRAPHY (2) The wind is directed across the mountain (roughly within 30° of Santa Barbara County is located on the perpendicular to the ridge line) .. .and south central coast of California, [the wind] should increase with approximately 35°N 120°W. To the north height. of the county lies the broad, flat and (in (3) The upstream temperature profile the summertime) hot San Joaquin Basin, exhibits an inversion or a layer of including the city of Bakersfield. Within strong stability near mountain top Santa Barbara County, which extends 43 hejght, with weaker stability at higher miles north from the city of Santa levels. Barbara, the terrain is rugged and mountainous (Figs. 5 and 6). Much of the county is under the administration of the

11 U.S. Forest Service's Los Padres National Other canyons which can be significant Forest. channelers of downslope winds into the proximity of Santa Barbara include The Santa Ynez Mountain ridge, with Winchester, Glen Annie, Barger, Mission, elevations from about 2000 feet to 4298 Rattlesnake, and Sycamore. feet, is oriented east to west along the south-facing coast of Santa Barbara B. STUDY METHOD, DATA ANALYSIS County. The 40-mile long ridge line is AND REDUCTION. notched with four significant openings: Nojoqui (pronounced nah-HO-wee) Pass The results obtained in this study are at 925 feet; Refugio Pass at 2254 feet; based on an examination of 31 significant San Marcos Pass at 2224 feet, and warming events (SWE) at Santa Barbara Romero Saddle at 3025 feet. The ridge in the years 1985 to 1991, inclusive. line extends to within six miles of the city SWEs are not defined by a specific of Santa Barbara, with canyons and temperature, but rather by a significant foothills stretching to within the city limits. anomalous departure from seasonal norms. For example, 81 degrees would Directly to the north of the Santa Ynez be classified as anomalous or significant Mountains lies the warming in February, but not in July. Valley. The intermittent Santa Ynez River Therefore, SWEs can occur in all drains the valley from above Gibraltar . More importantly, some SWEs Reservoir (1326 feet) to Bradbury Dam at were "sundowner'' events and some were (751 feet) to the ocean via not. Lompoc and Vandenberg AFB. Climatological data from several stations The city of Santa Barbara is built on a were utilized in this analysis. In the Santa narrow, one-to-five mile wide coastal plain Barbara area, hourly and special which rises precipitously to the ridge crest observations from the Santa Barbara of the Santa Ynez Mountains. From the Airport (SBA) FAA/Flight Service Station city, the Santa Ynez Range appears as a (No. 04-7905) were compiled for the 70 sharp and looming escarpment with month period between April 1985 and restricted access. The most visible and January 1991. Coincident records were significant indentation in the mountain obtained from the Santa Barbara ridge line as viewed from the Santa Cooperative Weather Station (No. 04- Barbara area is San Marcos Pass, six 7902) at El Estero Waste Treatment miles northwest of the city. A heavily Plant. Official weather observations at traveled scenic highway, California Route the Santa Barbara Harbormaster office 154, snakes from the 101 Freeway near and at City Fire Station No. 5 were also Santa Barbara across the ridge line at reviewed. San Marcos Pass. Directly below San Marcos Pass, and opening toward the Three-hourly surface observations from west side of Santa Barbara, is a steep­ SBA were employed in surface pressure walled chasm, Maria Ygnacia Canyon, gradient analysis. Sea level pressure which focuses and channels downslope gradients were computed from Santa winds onto the coastal strip (Figs. 7, ?a). Maria Airport (SMX) to SBA, and from

12 Bakersfield (BFL) to SBA. BFL data were were classified as severe downslope not available for 2200 PST, therefore windstorms (Category 3). 2100 PST data were substituted. All SLP data are listed in tenths of millibars with Mean statistical data are presented in the decimal point omitted. SLP data are tabular form for each of the four SWE normally temperature compensated, but categories in Tables II through V. may not be so adjusted in all cases. This Standard deviations (S) were computed should not significantly impact the for the SLP gradient field. Figures for integrity of the database. combined means of all SWE categories are given in Table VI. Rawinsonde data were selected from 1200 GMT (0400 PST) soundings (unless C. DISCUSSION otherwise noted) taken at Vandenberg AFB (VBG) and from the Naval Station at 1. Non-Sundowner Warming. Point Mugu (NTD). The city of Santa Barbara lies almost exactly halfway Ten of the subject SWEs showed no between these upper air sounding points. evidence of downslope wind and were Temperature and wind data were used as a control group within the study. compared for the 850 and 700 mb levels For these Category 0 events, diurnal and winds were profiled from 1000 feet to temperature curves were normal with the 500mb level. temperature maxima at approximately 1300 PST. In most cases, this strong Other temperature and weather records warming could be ascribed to a large were reviewed: From Santa Ynez Airport ridge dominating the area. The warm air ( IZA), from El Capitan State Park, the is sometimes connected to Santa Ana Harvest Oil Platform at Point Conception conditions developing over Ventura and and from the dam tender's weather log at Los Angeles counties. This situation Bradbury Dam (Lake Cachuma). Forest typically manifests itself in light easterly or Service observation records were variable winds up to 18000 feet at both obtained from Los Prietos Ranger Station VBG and NTD. Surface winds at Santa in the upper . In Barbara are light from the south to addition, as noted in the acknowledgment southwest and absolute SLP values are section, several private citizen weather notably higher than during downslope observers made their weather records wind episodes. and notes available to the author. Temperatures at Santa Barbara can Data for each SWE were analyzed and exceed 104 oF in Category 0 events. The classified based on criteria developed by boundary between the relatively hot air the author and specified in Table I. Of the over the littoral and the marine air over 31 SWEs, ten events showed no sign of Santa Barbara Channel can be sharp and downslope wind activity (Category 0), five active. Associated low-level wind shears events manifested weak downslope and air density changes are hazardous to regimes (Category 1 ), fourteen were aviation, sometimes contributing to air coincident with moderate or strong traffic control problems at Santa Barbara downslope winds (Category 2) and two Airport- located immediately adjacent to the ocean at Goleta.

13 2. Sundowner Wind Circulation. marine layer inversion is about 2000 feet during the summer and fall seasons. Downslope and offshore wind Within this marine layer, along the entire mechanisms that cause warming at Santa Santa Barbara littoral, winds are normally Barbara are very similar to those that light southerly or southeasterly. cause the larger scale Santa Ana winds near Los Angeles, and the smaller scale A strengthening of the north ~south warming winds at Avila Beach, near San pressure SLP gradient across the county Luis Obispo. Sundowner winds seem to usually signals the initialization of be a combination of hydraulic jump and downslope wind conditions at Santa mountain wave regime, with an Barbara. When minimum observed observable Bernoulli effect. Light to thresholds for sundowner conditions are moderate sundowners appear to have realized (p. 36), downslope winds begin to characteristics of a relatively simple low­ extrude through gaps in the Santa Ynez level gradient wind, while strong or severe Range. The adiabatic warming of low­ sundowners combine the full force of level air descending from the ridge line vertically propagating mountain waves. results in hydrostatic lowering of pressures along the coastal strip, further All categories of Santa Barbara increasing the north-south SLP gradient. sundowner winds are generated in similar fashion. A positive north to south sea Topographical considerations (i.e., the level pressure (SLP) gradient is a relatively low elevation and physical prerequisite for their development. These structure) make Nojoqui Pass the most gradients are typically established by cool favored place for early development of a air advection into the district from the sundowner flow. Sundowner winds north. The influx of cool air may be frequently begin here, channeling signaled by a synoptic scale cold front or downward toward Gaviota Beach, often short wave passage, or it may be seen in meeting the marine layer head-on, then the subtle ridging between the surface deflecting to the left (eastward) along the and 700 mb levels within a relatively beaches toward Santa Barbara, where warm air mass. In either case, a stable the modified sundowner is observed as a layer with a strong, surface-based 250° to 280° surface wind at, roughly, 10 inversion is established to the north of the to 25 knots. This sundowner airstream is Santa Ynez ridge line. Heights of this marked by sharp external boundaries; it inversion layer typically extend to does not mix with the marine layer and between 2000 and 4000 feet MSL. causes strong low-level turbulence along the beaches and at the airport. The north to south pressure gradient flow Temperature changes of 15-30°F have over the Santa Ynez ridge line initiates a been noted within a few hundred yards downslope wind regime. If the gradient near the beaches (Greg White, personal flow is weak, downslope winds through communication, 1991 ). the passes and gaps in the ridge line are blocked by the relatively cool, stable Sometimes, when downslope winds do marine layer which frequents Santa not occur through the higher passes, the Barbara. The average depth of this Nojoqui flow will be the only significant

14 sundowner stream into the Santa Barbara Marcos Road the wind is not felt, but may area. Frequently, however, the other be heard in the distance. At a given major passes and canyons along the observation point within the downslope Santa Ynez ridge line also direct flow, wind observations manifest strong downslope wind streams toward Santa surging gusts of wind with occasional Barbara. quiet periods and occasional abrupt changes in direction (Fig. 8). The main sundowner channel opening to Santa Barbara and Goleta is San Marcos While sundowners are channeled through Pass. Sundowner winds are generally gaps and canyons on the lee side of the measured at their greatest intensity Santa Ynez Mountains, sundowner winds directly below San Marcos Pass, from two are sometimes wrongly described as miles south of the Pass to the vicinity of simply "canyon" winds. The strongest Windy Gap along Highway 154 and and most persistent winds are not westward along the Maria Ygnacio Creek observed through the gaps, as in and San Antonio Creek drainages. Bernoulli flows, but are instead measured Downslope flow from San Marcos Pass is at various specific locations along the usually experienced as a northwest wind south facing slopes and at some sites on within the city of Santa Barbara and at the coastal plain. Santa Barbara Harbor, and as a north to northeast wind at Santa Barbara Airport. 3. Severe or Category 3 Sundowners.

North to northeast sundowner winds are Category 3 (severe) sundowner episodes sometimes directed into Santa Barbara are characterized by temperatures of through less prominent canyons to the 104 oF or more with winds of more than 20 north of the city. These include Barger, knots at the ocean and more than 50 Mission and Rattlesnake Canyons, as knots on leeward slopes of the Santa well as the Sycamore Creek drainage. An Ynez Range. Historical data suggest that 850mb flow to the east of true north tends windstorms of this magnitude have to de-activate the San Marcos Pass occurred at least 15 times since 1850. sundowner flow, while significantly increasing wave energy toward the east, Category 3 windstorms seem to follow a notably in the Montecito and Carpinteria somewhat narrow developmental course. districts. Synoptic scale analyses show a strong (roughly 5900m) ridge at 500mb centered The downslope regime tends to be over the Four Corners area within a few somewhat capricious and erratic with weeks on either side of the summer regard to boundary layer flow. For solstice (Fig. 8). A surface "thermal" low example, wind sensors may report calm pressure regime is centered near conditions at Santa Barbara Harbor and California's Imperial Valley. Low pressure downtown, while a low-level jet intersects off the Pacific Northwest coast supplies KEYT's TV Hill (elevation 450 feet MSL) the mechanism for cool air advection into with a resultant northwest gale. Forty northern and central California, while knot gusts may occur on Twinridge Road maintaining a southwest wind flow at while a few blocks away on Old San 500mb. The 500mb wind flow manifests

15 at least goo of backing from the northerly It is interesting to note that at the summit ridge top flow. At 925mb and 850mb, a of San Marcos Pass, winds during severe high pressure ridge extends inland across downslope events are generally light, central California from the Bay Area to the about 10 to 20 knots, and blow from the San Joaquin Valley, with accompanying Santa Ynez Valley (from the north or increases in pressures and stability from northwest). Temperatures at the pass north to south. Strong cool air advection usually hold in the 80's. is noted on the 850mb analysis (Fig. 9). While Category 1 or 2 downslope events In Santa Barbara County, a strong generally cause maximum diurnal surface inversion, as measured in the temperatures to occur between 1600 and Vandenberg sounding, reaches from 2000 1900 LST, Category 3 sundowners to 4000 feet MSL (Fig. 10) . The sounding produce very rapid temperature rises typically exhibits two other characteristics which tend to peak earlier, between 1200 which may impact on the development of and 1500 LST. One possible explanation mountain waves: ( 1) increasing wind with for this phenomenon is that Category 3 altitude, expected theoretically in an episodes are typically preceded by at application of the Scorer parameter, and least one day of moderate downslope (2) additional stable layers just below the activity. Thus, on Category 3 days there , as anticipated by Clark and is little boundary layer opposition from an Peltier. established Santa Barbara marine incursion. Furthermore, lee waves have Another feature present during severe already established flow positions on the sundowner wind events is strong heating south side of the Santa Ynez Range on in the upper Santa Ynez Valley. With day one, and may thereafter be in a better 500mb heights and thicknesses at high position for phasing with an increasing summertime values, intense heating southwesterly flow aloft. occurs in the Cachuma Lake/Los Prietos areas. Maximum temperatures at these Compressional heating occurs in sites have been documented at 105° to atmospheric layers above the lee side of 115 o or more during thes~ conditions, the Santa Ynez Range. This heating may creating a strong surface-based super be enhanced by downward vertical wave adiabatic lapse rate. It is not certain if this propagation through the troposphere. heating contributes in some way to the The presence and the strength of these development or the strengthening of the waves is confirmed by the effects of San Marcos sundowner wave, but there is sundowner airflow on aircraft approaching some suggestion that venting of hot air Santa Barbara Airport from the north of from the Santa Ynez Valley may be the Santa Ynez ridge line (p. 14). occurring. This could result from low-level northwest (up-valley) winds, generally 10 In severe sundowners, strong channels of to 20 knots, measured at Santa Maria, super-heated air reach from the lee Lompoc, Santa Ynez, and Bradbury Dam slopes below San Marcos Pass across in Category 3 episodes. the coastal strip, and can occasionally push all the way to the Channel Islands, some 25 miles to the south. Videotapes

16 taken from the vicinity of San Marcos Range is that of a sharp, steep Pass during the 1990 Category 3 escarpment. Atkinson (1981) and others windstorm clearly show the location, speak to the importance of this element; marked by a huge smoke plume, of a it is commonly asserted that maximum hydraulic jump boundary directly over the surface wind speeds are much greater city of Santa Barbara. with similar sharp topographic features. Atkinson quotes a study indicating that Modeling sundowner winds over the wind maxima are dependent upon the Santa Barbara area is difficult. With the presence of an inversion near the inclusion of mountain wave factors in mountaintop level on the windward side of severe events, this difficulty is the crest. Using data analogous to Santa compounded. In the first place, classical Barbara terrain features, this study hydraulic jump diagrams are not yielded a maximum wind of 40m/s (78 assignable to the Santa Barbara knots). This value approximates peak condition. The north-south flow over wind values extrapolated from the Maria Santa Barbara County is not laminar; it Ygnacio sensor northwest of the city of crosses a large area of rough terrain Santa Barbara, and from measurements before reaching the Santa Ynez Valley noted by ground observers (Figs. 13 and and Santa Ynez Mountains. Further, 14). there are significant valley winds that typically approach San Marcos Pass from While the effects of sundowner regimes in the northwest and a variable-strength the San Marcos Pass and Santa Barbara marine layer on the lee side of the pass to area can be documented and analyzed in consider. In addition, there are frequently general terms, individual events display gusty northwest winds across much of broad variability in location of impact and Santa Barbara Channel during severe in all measurable parameters. sundowners. Finally, synoptic scale flow reversal above 10000 feet adds yet D. FORECASTING SUNDOWNERS. another dimension to the modeling problem. It is essential that forecasters exercise synoptic and mesoscale pattern Notwithstanding the difficulties mentioned recognition skill to anticipate downslope above, an approximate sundowner flow windstorm development. Favorable diagram can be made for a severe event patterns, outlined in this paper, are now occurring at San Marcos Pass (Fig. 12). best viewed using gridded data. Although Assuming dry air, the wind flow follows lacking in fine detail, standard NGM and isentropic surfaces and indicates strong MRF models have been used with atmospheric perturbations throughout the success to forecast downslope wind troposphere. Surface temperatures at conditions at Santa Barbara from one to Santa Barbara could, within this context, three days in advance. reach values approaching 130°F. In the hours before a potential sundowner Downslope wind potential at Santa occurrence, and for the duration of any Barbara is somewhat enigmatic. The event, the computed SLP gradient field is shape of the lee side of the Santa Ynez the most important indicator of the

17 strength of any downslope wind event. the SMX-SBA gradient is less than Forecasters need to continually monitor 1.8mb. pressure gradient fields when the 2. Winds at 3000 feet MSL (see VBG potential for sundowners exist or when an upper air sounding, VBG profiler event is occurring. Perhaps the single data, or VBG Doppler radar) must best indicator of wind strength and flow from between 335 o and 025 o for duration is the pressure gradient between sundowner development to occur. Santa Barbara and Santa Maria. Another Wind speed at 3000 feet is normally gradient to monitor closely is the one about 20 knots, but a threshold between Santa Barbara and Bakersfield. speed of only 12 knots is supported by data analysis. The importance of wind profile information 3. The VBG sounding must exhibit a in forecasting wind events is noted by significant low-level inversion many downslope wind researchers. A extending to ~ 1500 to 3000 feet potential tool for forecasting these events MSL. in the Santa Barbara area is the recently 4. Category 1 sundowners are installed Vandenberg (VBG) Air Force observed when SMX-SBA SLP Base Doppler radar system (WSR-88D). gradients range from 1.8 to 4.0mb. The antenna for this radar is located 5. Category 2 sundowners are about 5 miles southeast of Santa Maria observed when SMX-SBA SLP Airport. In clear-air mode, Doppler radar gradients range from 3.5 to 6.5mb. can be used to profile wind layers through 6. Category 3 sundowners are a dry atmosphere. Although it cannot observed when SMX-SBA SLP detect vertical motion, tt has produced gradients are > 5.0mb, with the some spectacular imagery of precursor following parameters likely to be wind fields above the Santa Ynez Range. noted concurrently: National Weather Service meteorologist a. A sundowner flow has been Mike Wofford (NWSFO Oxnard) has observed at Santa Barbara during demonstrated considerable skill in at least the previous 24 hours. adapting the Doppler system to evaluating b. North-to-south SLP gradients Santa Barbara downslope events. This across Santa Barbara county are radar shows promise as a research tool stable or increasing. for future sundowner events (Figs. 15 and c. Strong insolation is occurring; all 16). known severe events have occurred between June and E. GUIDELINES FOR FORECASTERS. September but are most numerous in June and July. Based on supporting data compiled within d. Winds between 3000 feet and the context of this study, the following 18000 feet MSL back from rules apply for sundowner evaluation and approximately 360° to 250°, forecasting: respectively.

1. Sundowners have not been Forecasting specific meteorological observed to occur when the BFL­ parameters for downslope windstorms at SBA SLP gradient is negative, or if Santa Barbara requires an application of

18 techniques developed during many years forecasters should include low-level wind of observations. Einar Hovind, a Santa shear conditions in the terminal forecast Barbara consulting meteorologist with for Santa Barbara Airport. In addition, many years of experience in sundowner wind advisories or warnings should be forecasting, has observed the following considered for the affected zone (Personal communication, 1992): forecasts, as appropriate. The following products may be applicable during Santa Maria-Santa Barbara Sea Level sundowner conditions: Pressure Gradient (1) Red Flag Alert (Fire Weather) SMX-SBA SLP WIND RANGES GRADIENT (2) High Wind Warning/Wind Advisory less than 2 mb no downslope wind (3) Heat Advisory

2-3mb 20-30 knots (4) Small Craft Advisory 3-4mb 30-40 knots In addition, special weather statements 4-5mb 40-50 knots should be issued during downslope windstorms to update the situation, greater than 5 mb over 50 knots highlight specific effects, and address public concerns-which tend to heighten The author's experience in comparing during strong episodes. wind sensor reports from Maria Ygnacia Canyon versus pressure gradients As recently as 1990, the only readily demonstrates the remarkable reliability of available surface observation near the city this gradient/resultant wind guide. of Santa Barbara was at the Santa Barbara Airport (SBA) in Goleta. Forecasting maximum temperatures for However, this is one of the last locations Santa Barbara during sundowner events on the coastal strip to manifest is very difficult. This is due to the uneven sundowner conditions. Therefore, nature of the downslope flow caused by observations from SBA alone may fail to complex terrain and related turbulence. indicate a sundowner event in progress In general, the maximum surface even though strong conditions are temperature at Santa Barbara during a currently occurring elsewhere in the city. sundowner episode will exceed the Fortunately, surface weather observation potential temperature at 850mb. As a points in and near the city have increased rough estimate, the maximum greatly during the years since the Painted temperature during Category 1 and 2 Cave Fire. Temperature and wind data events is approximately 15 oF higher than can be monitored through the following the 1300 LST temperature at La Cumbre collection points: Peak (Alert Gage #2505). Remarkably, + Santa Barbara County Flood Control the surface temperature at Santa Barbara Alert Gages 2505, 2515, 2568, 2500, will exceed the potential temperature at 2510,2537,2542, 2563, and3090 700mb during Category 3 events! + Santa Barbara County When downslope windstorms are Control District Gages 26, 29, 31 , imminent or are occurring, aviation and 32.

19 + Spotter Network Bosart, Lance F., 1983: Analysis of a Sites in Santa Barbara 804, 805, California Eddy Event. Mon. Wea. Rev. 808, 809, 810, 811, 813, 814, 815, (AMS), 111, pp1619-1633. 820, 902, 907 Clark, John H. E. and Dembek, Scott R. , + U.S. Forest Service Automated 1990: The Catalina Eddy Event of July Weather Observation Sites at San 1987: A Coastally Trapped Mesoscale Marcos Pass and Glen Annie Response to Synoptic Forcing. Mon. Canyon. Wea . Rev. (AMS), 119, pp1714-1735.

+ KEYT Television on TV Hill and an Durran, Dale R. (Contrib. Ed.) 1986: associated downtown site. Mesoscale Meteorology and Forecasting, Peter S. Ray, Ed. American Vandenberg AFB wind profiler data and Meteorological Society, Boston, 793pp. Doppler radar imagery and wind profiles are now being made available to Elevatorski, Edward A., 1959: Hydraulic forecasters and researchers. It is only a Energy Dissipaters. McGraw-Hill Book matter of time before guidelines are Co. Inc, New York. established for the use of these diagnostic tools in downslope wind analysis. Finke, Brian W ., 1990: Sundowner Winds and the June 25-28 Santa Barbara Fire. Western Region Technical Attachment No V. CONCLUSION 90-30, National Weather Service Western Region, Salt Lake City. A significant mesoscale event, such as a sundowner, occurring over a heavily Ford, Raymond Jr., 1991: Santa Barbara populated coastal plain clearly presents a Wildfire: Fire on the Hills. McNally and threat to public safety. The technology, Loftin, Santa Barbara, 228pp. observational network, and forecast focus is now in place to do a better job of both Gomes, Daniel, et al., 1993: Sifting monitoring and predicting these Through the Ashes: Lessons Learned potentially dangerous events. Perhaps, in From the Painted Cave Fire. University of the future, lives, and property can be California, Santa Barbara, 194pp. saved as a result of further research into the sundowner regime, refinements, Fox, Robert W. and McDonald, Alan T. , modernization of forecast technique, and 1985: Introduction to Fluid Mechanics. close interagency cooperation. John Wiley & Sons, New York, 7 41 pp.

Hooke, William H. (Contrib. Ed.) 1986: VI. REFERENCES Mesoscale Meteorology and Forecasting, Peter S. Ray, Ed. American Atkinson, B. W., 1981 : Meso-Scale Meteorological Society, Boston, 793pp. Atmospheric Circulations. Academic Press, San Francisco, 495pp.

20 Horel, John, 1992: Mountain Waves, VII. ACKNOWLEDGMENTS Videotape lecture at the University of Utah. National Weather Service Western The following persons contributed time, Region Library, Salt Lake City. data, material and ideas used in the preparation of this paper. The assistance Independent Insurance Agents of Santa of these individuals is greatly appreciated. Barbara, 1982: The Lessons of the Sycamore Fire, Santa Barbara, California. Sally Cappon, Weather Observer, Santa Haagen Printing, Santa Barbara, 57pp. Barbara Chet Cash, U. S. Forest Service, Santa Jones, Douglas F., 1974: The Goleta Maria Simoom of 1859 ---A Summary of Facts. Mary Compton, Weather Observer, Santa Noticias, Vol 20 No 4, pp6-1 0, Santa Barbara Barbara Historical Society Museum, Chris Crabtree, Meteorologist, Santa Santa Barbara. Barbara Arnold Court, Em. Professor, CSU Long, R. R. , 1953: A Laboratory Model Northridge Resembling the "Bishop Wave" Peter C. Felsch, National Weather Phenomenon. Bull. Amer. Meteor. Soc., Service, Missoula, Montana

~4. 250-311 0 Dennis Gibbs, Hydrologist, Santa Barbara County Flood Control Meier, Keith, 1994: A Southern California James Goodridge, State of California Wind Event: An Alternative Explanation. Climatologist (retired) Western Region Technical Attachment Joan Hardie, Weather Observer, Santa No. 94-11, National Weather Service Barbara Western Region, Salt Lake City. Chick Hebert, Weather Observer, Santa Barbara Pettre, Paul, 1982: On the Problem of Einar I. Hovind, Consulting Meteorologist, Violent Valley Winds. Journal of the Santa Barbara Atmospheric Sciences, Vol. 39, pp Bruce Jones, U.S. Bureau of Reclamation 542-554. Damtender, Bradbury Dam Jay Lebonville, Weather Observer, Santa Ryan, Gary, 1994: Climate of Santa Barbara Barbara, California. Western Region Phil Mann, KEYT Television Weather, Technical Memorandum NWS WR-225, Santa Barbara National Weather Service Western Keith Meier, National Weather Service, Region, Salt Lake City. Salt Lake City, Utah Todd R. Morris, National Weather Service Western Region Headquarters Staff, Area Manager, Oxnard 1990: Downslope Windstorms and Daniel D. Ramar, Systems Engineer, San Mountain Waves. Western Region Jose Technical Attachment No 90-31, National Kelly Redmond, Western Region Climate Weather Service Western Region, Salt Center, Reno, Nevada Lake City. Peter Rodgers, Weather Observer, Santa Barbara

21 David Rosenberg, National Weather Service, Monterey Jim Shackelford, U.S. Forest Service, Los Prietos Ranger Station Ellen Soppe, Air Pollution Control District, Santa Barbara Darwin Tolzin, Pacific Missile Test Center, Point Mugu Greg White, El Capitan Lifeguard Headquarters, El Capitan Beach Mike Wofford, Meteorologist, NWS Forecast Office, Oxnard Morton G. Wurtele, Atmospheric Remote Sensing Laboratory, UCLA

22 , . ,----.r I .,;- ) ···'~ -· \~- -::;::;--- IF :! \ .! ( ~ ~/ Jochott Sprfn6,. ,...... _(. _ / <' r" .·J '/; " ~ Allt.. ~fiiiVOM _,.,... f '"' - ' ~Js a~oc>'sP'·· · , " ' L ·- -A f~~tl Wu 111W• •

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GOLETA BEACH Figure 1 . COUNTY PARK AN NOVO BURRO NAP OF SOUTHEASTERN SANTA BARBARA COUNTY BEACU COUNTY PARK SCAI.IIH MIUI SANTA BARBARA l • a :1 ~ ' a , ' !MI~OMUU~ _ I tO llvlYI - --·- JJ&4f~ r Weather Observer Sa.ys Relief· U'd wero work Will Come Soon; Ma.ny Shepard'• In way wu 011& Go to Beach . wqona carry Never In the history oC Sa.nta. Da.r­ pro~ble put \..fl..l· bu.ra. hu ther~ been lfUCh hut a.11 lha.t Ia dlatrlct wa preva.Jllnl' alnce tho Oja.l v.nd Ca.J"l)ln· ill t on the Von lerta. n r f'A •t.a.rt~( .. llrn. thfl llopn l'u.rk ullltrlct a'• r"""" rr" t l,,.n lrrln&" 111 thn .:rn."ll ut t he nOA.mea. Cl .'= llllf'cl u 11 (o \\'hilt~ ll p14rl of lhfO hr.u.t WIUI UUO tn 1 1l1u) fpr wor """<"rt wl11rl~t . tr 111 alu.lcHJ thul the hlch ' S liUI' IWUlh (J rr,.·ord W~AA !on·uot thrCJuch tha hoOA.t from lh., !urrnl llr"•· The •everlty cn1 Crom bill hol4n1•. lllaherl num~rc111• A.merl~ •l lo·ft (I jn Monda.y, .Tn,.,q 18,1917. n wlwn II ""''"· l~rt nylnK IJV~r tho alo~·. Into Hhr• ~ ··"· l\Jic.l llrove the nne•t uu~t Into All tho·~ olw .. lla n~e• M.nct Htur."'"· no plu.ce ~lniC thn Hall! . -• .w,. !110 lle\·ur.-ly doaf'o.l lu preveul thct pa.r­ 'li. (IJ:lol IIIL tiC'I,.. rrotn •lrtlnl( thru u~eh. .,.. ;.,r,;r tr( Sh,.rl 1 The hoew.t throuf(h t.h4t uvttnln« at:nt 1w:uc burn;:. thou~nda to thu IJ .. u.c ·h . T.-~uH nlacht 1 the lw the uumi.J•r wu11 IIIY.t .... rlw.lly dlnllnl•IH~ d. ''"UIItl lliUo U.lt .. ur~c:.te Crull\ the o~:~n HCit In juat lt u. ~ p.-11oft ot the llhe t,...tort' rnlllniKhl, 1L.t1d ~vc u. cool night 'I I to the clty. , lf'a.\'lng Oj l':ever Ut"CCJre hu,· ~ such numben oC 'nd chlldrt and wt P-f!ople •ou~r:ht the aurC to cool orr, hun- !&U it ot tl dredd CJC •ur! I.Jather11 titJent most oC the :ndt'rgone. HundM.y t-lthl"r In the wu.ter or lulling fl\ty-+flHpl on th ~ h~a c h. taklr'IIC an occaalona.l Figure 2. ~·pie lO\ piunl-)e tu ket-p I'UOI. Tho bath hou-.e SANTA BARBARA MJRNING PRESS a long Ca. Y~lltero.la.y served i::lu ba.thr.rtl, a.nd ther~ FEATURE STORY, 6/18 / 17. The :rd_a.y atte Wf'!re m~ny othf-rl! who UIUH1 lhttlr a.uto- headline reads "HEAT RECORDS tupply hi mobilell In which to lluo their bu.thlniC SET FOR CITY BY FIRES AND people to HUlt:~, It being t'llllma.t"d th11t during WIND" • The article quotes men we the da.)', Crom Gro.ha.m'a on the f'!a.wt, to Weather Bureau Cooperative heir ho.t : Car bE>:yond Ca11tlo Rock, over 1000 peo­ Observer George w. Russell. ·ere only IL pie took to the water during the day. (Courtesy, Mary Compton)

1t 'ot the • ...... ~ 1 ~ ~ t\rea a II f\/1 -~ n' "'"I u~n. ,..._,. ,_ older con- t '-'H. h S h ] : Y.eaterda.y a Ig C 00 b had ap- - (ew hours A musical progrll.m, to which the 24 I'U•~ oC pui.Jllc ha.a t)een lnv ltcti ..,111 '-- - •··-- , ;.:. • ,, .• • • 1 •• ... • • • ... . . - • . . • 1l ~ . ~tpartintnJ ef ~griculturr, illlmthtr ~uitau.

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Figure 3.

GEORGE RUSSELL'S WEATHER LOG, JUNE 1917.

'i (Courtesy of Tom Ross, l National Cl1matic Data Center) Figure 4. FIRE CLOSES IN ON SANTA BARBARA RESIDEN:E. John Bortolazzo climbed the roof of a Via Regina home in a valiant, but unsuccessful, attempt to save it fran the Painted Cave Fire. His "good neighbor" effort paralleled that of Jay Lebonville. (Courtesy of Santa Barbara News-Press)

26 1 N

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Po-i..n;t

Figure s. RELIEF MAP OF SANTA BARBARA COUNTY , CALIFORNIA

SBl\ - Santa Barbara Airport GVO - Gaviota SMP - San Marcos Pass SMX Santa Maria IZA - Santa Ynez Airport CAP - El Capitan· VBG­ Vandenberg AFB One Inch = l.\pprox 8 t-1iles LPC - i.anpoc OJY - Cuyama K FT · · · · · · · · ' ~ -ttttm •ttttttttt~~~L 1 ~ ~ !+111111 tI ll! uI I I I L Miles 0 10 20 30 40 50 60 70 80

N 00 FIG. 6 Santa Barbara County Profile (vert 1 Ox horiz) \ ~ \ . \. .. ) Yna \.. .J\'-. I \ i! "\• \, ' ...., .r '···"'\. I...... ,....._( ( ... r-·· J > -. .. LOS PRJETOS R.S. I \ u '. ~ ·-'"\. ....J ~ ..~. \ \ ' \ J:···~ ,-.... : . lb \ .. -J...... -- ~ .\ \ : ) : \_ J-,-... -- '· ) 1 , : i voir .._ '-.... J ./ ( r-' Gibraltar Rese "\ ) NORTH/ ·' -··?\ ..... ~ .. ~ i ! ( / ,l.. ·.. --~ J, 't '· ( ~L ! ~ l ·, -- ) '\ I ' .r--' A(j '· )7 : / / _? ·- ( . /.: \. i'· ) ' ' ' ~ } \ ) f \ \ / /T\)I ) · ~-~0'--. I ~j ··--···r\ · \\/ ~ ~ ,) ) ,.. \ ~ '( \--- ... ~ /' '.''·~ \.. ... > ( ) I' .· I . ' \ ·. ~ \.:f~ '-···::r-···...... r __,.

~., I r a{ ' ~t i J \jjg ( ~\ \ ~ ( \ \1, ~~ i \ - J'-'--,.,? ~

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Goleta Point FIG. 7 0 Surface Observation Points Santa Barbara Area 6. Weather Service Spotters 0 I 2 (without Wind) I I I I I Weather Reporting Sites A Weather Service Spotters March 1995 (with Wind) Approximate Scale ll/16 lnch·l mile \ \ .. .1 (_ 1,. • • ··-"- ··• ..../ "" 1--- _; \.. \ ' )...._ ...... J\ . .. "' \ ·. < .r ··.. J ? ... ) ' ··) ... - ~- · \ ) J ' cv )( Ynez r ( ( (J f \ : ~ l \ - .. '·.. l.-- ; ...... / """ / · \ $11nla ().,....__( .. ~ y ..._ \ .. -\ '_j "\ ..· -- ~ · .. ~ ··· ~ -· ­ lOS PRIETOS R.S. l ·' . i: . \ \ !\ ·~ ... \_)- (" "lI - . Y··, '\.. I )-- ~ ... ) \ ; :" ~\ -- ~ c::-··· } ' ~ ~,_m, 1,)~--:{'', .r' ( ··. ..('~ ·l ... \ . \) \I "\ ;. "'-. I -· . { NPRTH ! ./' "\ ) { r·· ) ; ... / '7 '· \ :"-h .'1 ...J ) : . '\\ ~' II l .. '"". . II , !"'"' ..A]Y J--!.. > I I ;: li ~ . () ~1'-·- l : I C: / l I fT'--- ( \!·~ ·' i ( C:: I )7( . COUNTY,£!1 CUMBRE 1 /',.: \ ( I I - ... ) i \: ) ..__.. .. I l ~ ) __..··()'-·' ) ,f· . ~ ') ~ ~· I \y·' ) t ~

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, -- 0 GOLETA­ -V""./~SCG 3090

Goleta Point

0 Surface Observation Points Figure 7a. ARFA OF STRONGEST) SUNOOWNER WINDS (shaded) fran 6. Weather Service Spotters 0 I 2 (without Wind) the San Marcos Pass downslope I I I I I A Weather Service Spotters wave . (with Wind) Approximate Sc.ale 11/16 lnch-1 mile TABLE I. SIGNIFICANT WARMING EVENT (SWE) CATEGORIES

DESCRIPTION CATEGORY

0 WARM ANOMAL Y/NON-SUNDOWNER. Control data. No downslope winds. Warm advection with moderate or strong diurnal heating usually associated with mean ridging over the area. Normal diurnal temperature curve. Light winds, onshore afternoon. Sea level pressure (SLP) relatively high. Surface temperature at SBA may reach 104 deg F (40 deg C).

1 WEAK SUN DOWNER. Maximum temperature occurs out- side normal diurnal curve. Surface winds tend offshore over 15 knots (8 m/s) at the ocean. Strongest winds in passes and canyons 30 knots (15 m/s).

2 MODERATE TO STRONG SUNDOWNER. Temperature maximum occurs outside normal diurnal curve and is 15 deg F (8 deg C) or more above normal. Gusty winds, usually offshore, greater than 15 knots at coast. Stronge~t winds 30 to 50 knots (15 to 26 m/s) in passes and canyons.

3 SEVERE SUNDOWNER. Surface temperature exceeds 104 deg F during early or mid-afternoon. Gusty off- shore winds reach 20 knots (1 0 m/s) or more at the ocean. Pass and canyon winds exceed 50 knots (26 m/s). SLP relatively suppressed. Mainly occurs in June, July, or September.

31 Figure 8. LOWNSWPE WIND POOFILE, JUNE 1-7, 1994. For several days Ha~ia Ygnacio Uppe~ in early June, 8trong down­ 50 ~----~r-----~------~------+------+--~ slope winds were monitored by County Flood Control through their Maria Ygnacio wind gage. 2563 Note the very sudden onset of the winds during the afternoon hours each day. The winds i quit suddenly, also. This is 491 II 1\ II Ill\ I typical of sundowner profiles.

I 391 ll !II! l J w I'V p e ~ h 0 201 I \ 1111 11 .11.11 I I llll I ll ~

1 I 1 r { 191 I ll~ 1 r \

r/'-\,/.. / 6/1994 9 DAY 1 2 . 3 4 5 6 1 8 MONTH 6-) ~ .., - ., .._, - "' .. _.. _,...._ .., .... II - ,. . ~ ~ • ..,., l I ~ ' ' ' .,....

:r.igur~ 9. 850mb MAP TYPE FOR CATEGJRY 3 \'liNDS'IDRM, JUNE 27, 1990. Note the very strong (20°C) temperature gradient across California.

'.I'

,

. . . .j"~~ . . 7''::.:-LJ .·. . ·~: m ... .· .. :: .'" WEDNESDAY, JUNE 27, 199 0

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Figure 11. VANDENBERG AFB UA SOUNDING 6/27/90 1200 UTC The strong inversion extends to the level of the Santa Ynez Ridge. . .. - . , Figure 12. PIDJECI'ED ISENI'OOPIC FLOW AT SANTA 8.l\RBARA, 6/27/90. Two or more high amplitude waves would be expected in the irrmediate downstrean flow. Note the blocking marine layer l ower right near Highway 101.

21,000 ------=:::::::=== 324 20,000 19,000 --~----~~-~~------~~------18,000 ::---_j't----I----::::::=::::::-~~----~L---=7:::::::::::===~ 322 17,000 ____.::~~~~~~---~-\------;:...__-?~---- 16,000 320 15,000 318 14,000 ::-----=::~::::=-=~:._--==--~:--~\---j--j:__/.?--7-----

13,000 316 12,000 -=o.-.....:::--_---=::::::::-::::~--::=:---\-+-\--t----t+-+--;---r----

11 .ooo ---~~--~=---.\~-\-\--\--\---;Y-J---;----r-.----:"7'""---....:::::::::::: 314 10,000 9,000 ~~----~~~~~~~--rr~-r~~~~~ 8,000 ------~~~~H-~r.r~--~~ 312 7,000 310 6,000 -:::::::::::::__ __:_-=::::::::==--====-....::::;:---\-\--H-~-:::J-+t--H---ht---=:::=:::::::::---

5,000 --===--==:::::::~~ffi+\---f-1~-fh~?-----==-___::: 308 4,000 ------=;;:;;>""..:::..___-----; 306

3,000 304 2,000 ---- 302 1,000 294 Surface ---­ Height in Feet D8

NORTH

36 FIG 13

Figure 13. MARIA YG~CIO RIDGE FOLLOWING PAINTED CAVE FIRE IN 1990 .

Figure 14. SANT.l\ BARBZ\Rl\ COUNl'~ FLOOD CONTROL MEr SENSOR ARRAY ON MARIA Y~CIO RIDGE.

FIG 14

37 0 4 / 07/ 95 19 53 BASE UEL 26 \) 62 NM . 27 NM RES 10/ 13/ 94 00 : 12 ROA : KUBX 34/ 50/ 16N ~ 1321 FT 120/ 23/ 45W ...., ~ ELEI)= 0 . 5 OEG t10DE 8 / 32 CNTR 0DEG 0NM .- ~- .. · < .~ ~ MAX= -81 KT 73 KT ::;

Q15 STI 1940 R PROD RCUD : P PPS Figure 15 . r.. = KUE: X 1946 54 3 4 \ 07/ 1945 ARCHIVE VBG NEXRAD VIEW, INITIAL PHASE UNIT 1 READ DONE OF OOWNSLOPE WIND EVENT I -- ~ HARD COPY 13 OCT 94. Radar is in Clear ___...... f.:~- Air Mcx:le at 0 . 5 degrees. ..._...,~_'::) c""'--....·---J~ --~ ~-~-·:~~) ...... _~ HARDCOPY REOU ES; T ·~ ...... __ .. Sundowner episcx:le was forecast "'• ·~') ._ AC CEPTED ' ~-- / _.-J for this evening. 5 : 12 pm PDT . .._--~