DOCSLIB.ORG

The Sundowner Winds Experiment (SWEX) Pilot Study: Understanding Downslope Windstorms in the Santa Ynez Mountains, Santa Barbara, California

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Sundowner Winds Experiment (SWEX) Pilot Study: Understanding Downslope Windstorms in the Santa Ynez Mountains, Santa Barbara, California APRIL 2020 C A R V A L H O E T A L . 1519 The Sundowner Winds Experiment (SWEX) Pilot Study: Understanding Downslope Windstorms in the Santa Ynez Mountains, Santa Barbara, California a,b b a,b a c LEILA CARVALHO, GERT-JAN DUINE, CHARLES JONES, KATELYN ZIGNER, CRAIG CLEMENTS, c c a a d HEATHER KANE, CHLOE GORE, GARRET BELL, BRANDI GAMELIN, DAVE GOMBERG, d d d d e e TODD HALL, MARK JACKSON, JOHN DUMAS, ERIC BOLDT, ROB HAZARD, AND WOODY ENOS a Department of Geography, University of California, Santa Barbara, Santa Barbara, California b Earth Research Institute, University of California, Santa Barbara, Santa Barbara, California c Department of Atmospheric Sciences, San José State University, San Jose, California d National Weather Service, Los Angeles and Oxnard, California e Santa Barbara County Fire Department, Santa Barbara, California (Manuscript received 19 June 2019, in final form 15 January 2020) ABSTRACT Sundowner winds are downslope gusty winds often observed on the southern slopes of the Santa Ynez Mountains (SYM) in coastal Santa Barbara (SB), California. They typically peak near sunset and exhibit characteristics of downslope windstorms through the evening. They are SB’s most critical fire weather in all seasons and represent a major hazard for aviation. The Sundowner Winds Experiment Pilot Study was de- signed to evaluate vertical profiles of winds, temperature, humidity, and stability leeward of the SYM during a Sundowner event. This was accomplished by launching 3-hourly radiosondes during a significant Sundowner event on 28–29 April 2018. This study showed that winds in the lee of the SYM exhibit complex spatial and temporal patterns. Vertical profiles showed a transition from humid onshore winds from morning to mid- afternoon to very pronounced offshore winds during the evening after sunset. These winds accompanied mountain waves and a northerly nocturnal lee jet with variable temporal behavior. Around sunset, the jet was characterized by strong wind speeds enhanced by mountain-wave breaking. Winds weakened considerably at 2300 PDT 29 April but enhanced dramatically at 0200 PDT 29 April at much lower elevations. These tran- sitions were accompanied by changes in stability profiles and in the Richardson number. A simulation with the Weather Research and Forecasting (WRF) Model at 1-km grid spacing was examined to evaluate the skill of the model in capturing the observed winds and stability profiles and to assess mesoscale processes associated with this event. These results advanced understanding on Sundowner’s spatiotemporal characteristics and driving mechanisms. 1. Introduction the southern-facing slopes of the SYM. These winds typically intensify from early evening to morning hours Coastal Santa Barbara County (SB), with a pop- and are known as ‘‘Sundowner winds’’ or ‘‘Sundowners’’ ulation exceeding 130 000 inhabitants, is among the most (Ryan 1996; Blier 1998). exposed communities to wildfire hazards in southern All major wildfires affecting SB coast have exhibited California (Kolden and Abatzoglou 2018). The Santa significant fire spread rates toward the SB wildland- Ynez Mountains (SYM) rise abruptly from coastal SB urban interface due to Sundowners. Some dramatic separating the Pacific Ocean on its south face from the examples of these rapidly spreading wildfires fueled by Santa Ynez Valley (SYV) on its north face. Downslope, strong Sundowners are: Eagle Canyon (September dry and gusty windstorms are frequently observed on 1979), Painted Cave (June 1990), Gap (July 2008), Tea- House (November 2008), Jesusita (May 2009), Sherpa Supplemental information related to this paper is available (June 2016), Whittier (July 2017), and Thomas Fire at the Journals Online website: https://doi.org/10.1175/MWR- (December 2017); the latter is considered the largest D-19-0207.s1. wildfire in Southern California’s history to date. Although ignited in Santa Paula (Ventura County) during persis- 2 Corresponding author: Leila M. V. Carvalho, [email protected] tent Santa Ana winds with gusts as high as 35 m s 1 DOI: 10.1175/MWR-D-19-0207.1 Ó 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses). Unauthenticated | Downloaded 09/27/21 07:32 AM UTC 1520 MONTHLY WEATHER REVIEW VOLUME 148 (Fovell and Gallagher 2018), the Thomas Fire further strong gusts, spatiotemporal variability of winds leeward of spread toward Montecito, SB, on the evening of the SYM, and mountain waves that can enhance wind- 16 December due to the strong Sundowner winds storms posing significant hazards to aviation. Moreover, (Kolden and Abatzoglou 2018). According to the the existing network of surface stations and the wind California Department of Forestry and Fire Protection, profiler installed at KSBA, though useful in evaluating these tragic events have caused injuries and fatalities, local conditions, are insufficient to examine mechanisms destroyed hundreds of properties and cost millions of explaining the observed wind variability downwind of dollars in suppression efforts. Additionally, they led the SYM and in coastal SB. KSBA is located near to massive evacuations and disruption of schools and the coast and is often influenced by a stable and cool businesses, created unbearable air pollution and environ- marine boundary layer (MBL) that significantly influ- mental problems, among many other issues. Therefore, ences winds near ground level. Consequently, significant improved weather warnings of these events, including gradients in winds exist between the coast and foothills greater lead time and spatiotemporal specificity of where of the SYM during Sundowners (Duine et al. 2019). For winds will be strongest is critical in supporting a rapid re- example, Hatchett et al. (2018) evaluated a climatology sponse in case of a wildfire. of Sundowner events (1979–2014) using KSBA and Despite the importance of Sundowners, little is known could not properly identify the remarkable Sundowner about the spatiotemporal variability and mechanisms event that affected eastern SB and Montecito during the driving these events. Contrary to Santa Ana winds that Jesusita Fire (May 2009). That event was clearly de- prevail during fall and winter seasons (Hughes and Hall tectable in other stations on the SYM slopes (Cannon 2010; Jones et al. 2010), Sundowners occur year round et al. 2017) and widely recognized by the NWS LOX and though appear more frequent during spring (Hatchett local meteorologists. These results demonstrate the et al. 2018). Blier (1998) noticed that significant cross- large degree of spatial variability of Sundowners and mountain flow over the SYM ridgeline is necessary for suggest the strong control of the MBL on temperature strong offshore (northerly) winds to erode the marine and winds near ground level (Duine et al. 2019). boundary layer that typically exists. That study also Numerous observational and modeling studies have showed that multiple synoptic conditions can lead to been proposed to explain the dynamics of downslope strong cross-mountain winds, and suggested that these winds in Alpine-type of mountains (Klemp and Lilly forcings maybe seasonally dependent. The multiplicity 1975; Smith 1979, 1985; Durran and Klemp 1987; Durran of synoptic settings conducive to Sundowners was also 1990; Gallus and Klemp 2000; Durran 2003; Vosper identified in Cannon et al. (2017) based on case studies, 2004; Grubisic´ and Billings 2007, 2008; Jiang and Doyle some of them related to major wildfires (such as the 2008; Lawson and Horel 2015). However, few investi- Painted Cave and Jesusita fires). Ryan (1996) found gations have been conducted to understand the inter- that strong mean sea level pressure (MSLP) differences action between downslope winds and a stable and cool between Santa Maria (KSMX) and Santa Barbara MBL in coastal ranges with moderate elevations, which (KSBA) airports are significantly associated with strong is typically observed in SB and other coastal areas in Sundowners (typically with a N-NW direction) in the lee California. Additionally, upstream conditions such as of the western section of the SYM. Sukup (2013) noticed the v-shaped SYV and the presence of the San Rafael that MSLP differences between KSBA and Bakersfield Mountains with elevations exceeding the highest peaks airports (KBFL) could be a better predictor for the in the SYM are important features to understand N-NE Sundowner winds that typically affect the eastern Sundowner winds. parts of the SYM. Cannon et al. (2017) investigated dynamical mecha- The National Weather Service Office in Oxnard (here- nisms associated with significant episodes of Sundowner after, NWS LOX) considers a significant Sundowner event winds based on simulations with the Weather Research when atmospheric conditions favor cross-mountain and Forecasting (WRF) Model at 2-km resolution. They (offshore) winds with sustained wind speeds $30 mph hypothesized that the cross-mountain winds generated 2 2 ($13.4 m s 1) and/or gusts $35 mph (15.6 m s 1)in gravity waves that further accelerated downwind in the stations leeward of the SYM. The NWS LOX has lee of the SYM due to the presence of critical layers utilizedthepressuredifferencecriteria(Ryan 1996; (Durran and Klemp 1987; Durran 1990, 2003). They Sukup 2013) as a rule of thumb to forecast Sundowners. showed that a mean-state critical layer, attributable to While MSLP differences have been successfully used in wind backing and reversal with height in the lower tro- forecasting the potential for Sundowners on synoptic posphere above mountain top, could be one possible time scales, these measures alone are not sufficient to mechanism related to the acceleration of winds. However, predict mesoscale features such as the onset and end of this mechanism could not explain all case-studies Unauthenticated | Downloaded 09/27/21 07:32 AM UTC APRIL 2020 C A R V A L H O E T A L . 1521 investigated in that study. In some situations, self- results of the experiment, focusing on observational an- induced critical layers (identified with Richardson alyses (section 5a) and simulations (section 5b).
Load more

Recommended publications
  • WRF Simulation of Downslope Wind Events in Coastal Santa Barbara County
    UC Santa Barbara UC Santa Barbara Previously Published Works Title WRF simulation of downslope wind events in coastal Santa Barbara County Permalink https://escholarship.org/uc/item/8h89t6zv Journal ATMOSPHERIC RESEARCH, 191 ISSN 0169-8095 Authors Cannon, Forest Carvalho, Leila MV Jones, Charles et al. Publication Date 2017-07-15 DOI 10.1016/j.atmosres.2017.03.010 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Atmospheric Research 191 (2017) 57–73 Contents lists available at ScienceDirect Atmospheric Research journal homepage: www.elsevier.com/locate/atmosres WRF simulation of downslope wind events in coastal Santa Barbara County Forest Cannon a,b,⁎, Leila M.V. Carvalho a,b, Charles Jones a,b,ToddHallc,DavidGombergc, John Dumas c, Mark Jackson c a Department of Geography, University of California Santa Barbara, USA b Earth Research Institute, University of California Santa Barbara, USA c National Oceanic and Atmospheric Administration, National Weather Service, Los Angeles/Oxnard Weather Forecast Office, USA article info abstract Article history: The National Weather Service (NWS) considers frequent gusty downslope winds, accompanied by rapid Received 13 June 2016 warming and decreased relative humidity, among the most significant weather events affecting southern Califor- Received in revised form 6 March 2017 nia coastal areas in the vicinity of Santa Barbara (SB). These extreme conditions, commonly known as “sun- Accepted 9 March 2017 downers”, have affected the evolution of all major wildfires that impacted SB in recent years. Sundowners Available online 10 March 2017 greatly increase fire, aviation and maritime navigation hazards and are thus a priority for regional forecasting.
    [Show full text]
  • A Surface Observation Based Climatology of Diablo-Like Winds in California's Wine Country and Western Sierra Nevada
    fire Short Note A Surface Observation Based Climatology of Diablo-Like Winds in California’s Wine Country and Western Sierra Nevada Craig Smith 1,2,*, Benjamin J. Hatchett 1 ID and Michael Kaplan 1 1 Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA; [email protected] (B.J.H.); [email protected] (M.K.) 2 Cumulus Weather Solutions, LLC, Reno, NV 89511, USA * Correspondence: [email protected]; Tel.: +1-541-231-4802 Received: 23 May 2018; Accepted: 20 July 2018; Published: 23 July 2018 Abstract: Diablo winds are dry and gusty north-northeasterly downslope windstorms that affect the San Francisco Bay Area in Northern California. On the evening of 8 October 2017, Diablo winds contributed to the ignitions and rapid spread of the “Northern California firestorm”, including the Tubbs Fire, which burned 2800 homes in Santa Rosa, resulting in 22 fatalities and $1.2 B USD in damages. We analyzed 18 years of data from a network of surface meteorological stations and showed that Diablo winds tend to occur overnight through early morning in fall, winter and spring. In addition to the area north of the San Francisco Bay Area, conditions similar to Diablo winds commonly occur in the western Sierra Nevada. Both of these areas are characterized by high wind speeds and low relative humidity, but they neither tend to be warmer than climatology nor have a higher gust factor, or ratio of wind gusts to mean wind speeds, than climatology. Keywords: Diablo winds; downslope windstorms; Northern California; wildfire meteorology 1.
    [Show full text]
  • The Sundowner Winds of Santa Barbara, California
    702 WEATHER AND FORECASTING VOLUME 13 The Sundowner Winds of Santa Barbara, California WARREN BLIER Department of Atmospheric Sciences, University of California, Los Angeles, Los Angeles, California (Manuscript received 10 September 1996, in ®nal form 24 February 1998) ABSTRACT Signi®cant downslope wind and warming events periodically occur along a short segment of the southern California coast in the vicinity of Santa Barbara. This region is characterized by a unique mesoscale topography: over a length of about 100 km the coastline is oriented approximately west±east, with the adjoining narrow coastal plain bounded by a steeply rising (to elevations greater than 1200 m) and coast-parallel mountain range. Called Sundowner winds because they often begin in the late afternoon or early evening, their onset is typically associated with a rapid rise in temperature and decrease in relative humidity. In the most extreme Sundowner wind events, wind speeds can be of gale force or higher, and temperatures over the coastal plain, and even at the coast itself, can rise signi®cantly above 37.88C (1008F). In addition to causing a dramatic change from the more typical marine-in¯uenced local weather conditions, Sundowner wind episodes have resulted in signi®cant property and agricultural damage, as well as extreme ®re danger. They have, in fact, been associated with many of the most destructive con¯agrations that have occurred in the Santa Barbara region. In the present study, three different Sundowner wind episodes are examined. These include midsummer and midautumn events primarily manifested by extremely warm temperatures, and a winter season event notable for its damaging winds.
    [Show full text]
  • Sundowner Winds
    SUNDOWNER WINDS A Report on Significant Warming Events Occurring in Santa Barbara, California. Gary Ryan Weather Service Office Santa Maria, CA July 1991 SUNDOWNER WINDS. A REPORT ON SIGNIFICANT WARMING EVENTS OCCURING IN SANTA BARBARA, CALIFORNIA. INTRODUCTION. Along the Pacific coastline, beneath the ridges and canyons of the Santa Ynez Mountains, Santa Barbara, California enjoys some of the earth’s most favorable weather. Mediterranean in classification, the climate is vintage southern California: an average high temperature of about 70 degrees year round, a predominately winter season rainfall of about 16 inches a year and, generally, a light and variable wind pattern. The infamous Santa Ana winds which occasionally ravage the counties of Ventura, Los Angeles and Orange to the south leave the Santa Barbara area virtually untouched. The only disturbance to this idyllic picture comes when downslope winds pour across passes in the Santa Ynez Range, descending onto the Santa Barbara littoral. These winds are “sundowners,” Santa Barbara’s special version of the Santa Ana regime. Sundowners frequently occur in the late afternoon or evening hours – hence the name. Light sundowners create irregular rises in temperature downtown with gentle offshore breezes. Stronger sundowners, occurring two or three times a year, can create sharp temperature rises, local gale force winds, and significant weather-related problems. Rarely, probably about a half dozen times in a century, an “explosive” sundowner occurs. These extremely strong and hot winds present a dangerous weather situation. In these events, super heated air from the Santa Ynez Valley bursts across the Santa Ynez Mountains and onto the coastal plain, reaching gale force or higher speeds within the city.
    [Show full text]
  • Evaluating the Ability of FARSITE to Simulate Wildfires Influenced by Extreme, Downslope Winds in Santa Barbara, California
    fire Article Evaluating the Ability of FARSITE to Simulate Wildfires Influenced by Extreme, Downslope Winds in Santa Barbara, California Katelyn Zigner 1,* , Leila M. V. Carvalho 1,2 , Seth Peterson 1, Francis Fujioka 3, Gert-Jan Duine 2 , Charles Jones 1,2, Dar Roberts 1,2 and Max Moritz 1,2,4 1 Department of Geography, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; [email protected] (L.M.V.C.); [email protected] (S.P.); [email protected] (C.J.); [email protected] (D.R.); [email protected] (M.M.) 2 Earth Research Institute, University of California, Santa Barbara, CA 93106, USA; [email protected] 3 CEESMO, Chapman University, Orange, CA 92866, USA; [email protected] 4 University of California Cooperative Extension, Agriculture and Natural Resources Division, Oakland, CA 94607, USA * Correspondence: [email protected] Received: 12 June 2020; Accepted: 7 July 2020; Published: 10 July 2020 Abstract: Extreme, downslope mountain winds often generate dangerous wildfire conditions. We used the wildfire spread model Fire Area Simulator (FARSITE) to simulate two wildfires influenced by strong wind events in Santa Barbara, CA. High spatial-resolution imagery for fuel maps and hourly wind downscaled to 100 m were used as model inputs, and sensitivity tests were performed to evaluate the effects of ignition timing and location on fire spread. Additionally, burn area rasters from FARSITE simulations were compared to minimum travel time rasters from FlamMap simulations, a wildfire model similar to FARSITE that holds environmental variables constant. Utilization of two case studies during strong winds revealed that FARSITE was able to successfully reconstruct the spread rate and size of wildfires when spotting was minimal.
    [Show full text]
  • A Defensible Community?
    A Retrospective Study of Montecito Fire Protection District’s Wildland Fire Program during the 2017 Thomas Fire October 23, 2018 A DEFENSIBLE COMMUNITY? | P a g e This page intentionally left blank. i | P a g e Table of Contents Executive Summary ................................................................................................................................................... iii Introduction ................................................................................................................................................................1 Methods .................................................................................................................................................................1 The Community of Montecito ................................................................................................................................3 History of Montecito’s Wildland Fire Program Policy and Actions ........................................................................5 Existing Emergency Preparedness Programs and Community Education ..........................................................7 Structures ...............................................................................................................................................................8 The Wildfire Environment – pre-Thomas Fire ............................................................................................................8 Weather ..................................................................................................................................................................8
    [Show full text]
  • Noaa Technical Memorandum Nwswr-240 Downslope
    NOAA TECHNICAL MEMORANDUM NWSWR-240 DOWNSLOPE WINDS OF SANTA BARBARA, CALIFORNIA ) Gary Ryan . NEXRAD Weather 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 Fog and l.Qw Slratus at I.DI Angeles International Airport Donald M. Gales, 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 Precipitation at BakeBiield, California, Uling Pressure Gredient Vectors. Earl T. Rlddiough, July 1972. (COM 7211148) 79 Climate 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 Wind Records. G lenn proclices, or to relote progress to a limited audience.
    [Show full text]
  • 2021 Community Wildfire Protection Plan (CWPP)
    CITY OF SANTA BARBARA February 2021 Printed on 30% post-consumer recycled material. Table of Contents SECTIONS Acronyms and Abbreviations ..........................................................................................................................................................v Executive Summary ....................................................................................................................................................................... vii 1 Introduction ............................................................................................................................................................................. 1 1.1 Purpose and Need ........................................................................................................................................................... 1 1.2 Development Team ......................................................................................................................................................... 2 1.3 Community Involvement ................................................................................................................................................. 3 1.3.1 Stakeholders ................................................................................................................................................... 3 1.3.2 Public Outreach and Engagement Plan ........................................................................................................ 4 1.3.3 Public Outreach Meetings .............................................................................................................................
    [Show full text]
  • City of Goleta Community Wildfire Protection Plan
    COMMUNITY WILDFIRE PROTECTION PLAN Prepared for: City of Goleta Neighborhood Services and Public Safety Department 130 Cremona Drive, Suite 100 Goleta, California 93117 March 20, 2012 Prepared by: Geo Elements, LLC PO Box 955 Cedar City, Utah 84721 Community Wildfire Protection Plan Mutual Agreement Page The Community Wildfire Protection Plan developed for the City of Goleta: Was collaboratively developed. Interested parties and federal land management agencies managing land in the vicinity of the City of Goleta have been consulted. This plan identifies and prioritizes areas for hazardous fuel reduction treatments and recommends the types and methods of treatment that will protect the City of Goleta. This plan recommends measures to reduce the ignitability of structures throughout the area addressed by the plan. The following entities mutually agree with the contents of this Community Wildfire Protection Plan: ________________________________________________________ Daniel Singer City of Goleta City Manager ________________________________________________________ Michael Dyer Santa Barbara County Fire Chief ________________________________________________________ Robert Lewin San Luis Obispo Unit Chief, California Department of Forestry & Fire Protection This page intentionally left blank. TABLE OF CONTENTS 1. INTRODUCTION ................................................................................................................................................ 11 1.1 PURPOSE OF THE PLAN .......................................................................................................................
    [Show full text]
  • Synoptic-Scale Differences Between Sundowner and Santa Ana Wind Regimes in the Santa Ynez Mountains, California Benjamin J
    Brief Communication: Synoptic-scale differences between Sundowner and Santa Ana wind regimes in the Santa Ynez Mountains, California Benjamin J. Hatchett1, Craig M. Smith1, Nicholas J. Nauslar2,3, and Michael L. Kaplan1 5 1 Division of Atmospheric Science, Desert Research Institute, Reno, Nevada, 89512, USA 2 Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, Norman, Oklahoma, 73072, USA. 3 NOAA/NWS/NCEP Storm Prediction Center, Norman, Oklahoma, 73072, USA Correspondence to: Benjamin J. Hatchett ([email protected]) 10 Abstract. Downslope “Sundowner” winds in southern California’s Santa Ynez Mountains favor wildfire growth. To explore differences between Sundowners and Santa Ana winds (SAW), we use surface observations from 1979-2014 to develop a climatology of extreme Sundowner days. The climatology was compared against an existing SAW index from 1979-2012. Sundowner (SAW) occurrence peaks in late spring (winter). SAWs demonstrate amplified 500 hPa geopotential heights over western North America and anomalous positive inland mean sea level pressures. Sundowner-only conditions display zonal 15 500 hPa flow and negative inland sea level pressure anomalies. A low-level northerly coastal jet is present during Sundowners but not SAW. 1 Introduction The combination of episodic low relative humidity and strong winds, complex terrain, and fuel conditions (e.g., load, moisture, and continuity) coupled with extensive wildland-urban interfaces (WUI) in southern California produces 20 significant wildfire hazards with frequent large, severe, and costly fires (Westerling et al. 2004). In the semiarid steeplands of the Santa Ynez mountains and other Transverse ranges of southern California (Figure 1a), fire represents a critical component of dominantly shrubland ecosystems (Moritz et al.
    [Show full text]
  • San Marcos Pass - Eastern Goleta Valley Mountainous Communities Community Wildfire Protection Plan
    San Marcos Pass - Eastern Goleta Valley Mountainous Communities Community Wildfire Protection Plan Submitted February 20, 2019 This page is intentionally left blank. SAN MARCOS PASS - EASTERN GOLETA VALLEY MOUNTAINOUS COMMUNITIES COMMUNITY WILDFIRE PROTECTION PLAN MUTUAL AGREEMENT PAGE This Community Wildfire Protection Plan was developed for the San Marcos Pass - Eastern Goleta Valley communities within Santa Barbara County: ./ Was collaboratively developed. Interested parties, key stakeholders, local fire departments, and federal land management agencies managing land in the vicinity of the Planning Area have been consulted . ./ This plan identifies and prioritizes areas for hazardous fuel reduction treatments and recommends the types and methods of treatment that will enhance protection of communities within the Planning Area . ./ This plan recommends measures to reduce the ignitability of structures throughout the area addressed by the plan. The following entities mutually agree with the contents of this Community Wildfire Protection Plan: Approved by: Steve L vagnino, Chair Santa Barbara County Board of Supervisors Approved by: · arbara County Fire Department Approved by: Fire Chief, San Luis Obispo Unit - CAL FIRE This page is intentionally left blank. Acknowledgments The following communities, agencies, and stakeholders were involved in the collaborative process in preparation of the San Marcos Pass and Eastern Goleta Valley Mountainous Communities Community Wildfire Protection Plan (CWPP): CWPP Working Group Dennis Bozanich –
    [Show full text]
  • EXTREME NORTHEASTERLY WIND EVENTS in the HILLS ABOVE MONTECITO, CALIFORNIA SCOTT SUKUP National Weather Service, Los Angeles/Oxnard, California
    EXTREME NORTHEASTERLY WIND EVENTS IN THE HILLS ABOVE MONTECITO, CALIFORNIA SCOTT SUKUP National Weather Service, Los Angeles/Oxnard, California ABSTRACT Extreme northerly wind events are a forecast challenge along the south coast of Santa Barbara County in southern California. Often called “sundowners” because of their tendency to occur during the evening hours, these extreme wind events can produce damaging gale force winds and dangerous fire weather conditions. In the present study, the usefulness of mean sea level pressure (MSLP) gradients are examined with regards to forecasting extreme northeasterly winds, specifically in the hills above Montecito. It is found that MSLP differences from Santa Barbara to Santa Maria (SBA-SMX) and Santa Barbara to Bakersfield (SBA-BFL) show similar skill in predicting extreme northeasterly wind gusts near Montecito. However, it is shown that the SBA-BFL MSLP difference may be a better predictor when it reaches extreme values. It is also demonstrated that there are factors other than MSLP differences that need to be considered when forecasting gusty northeast winds in the hills above Montecito. INTRODUCTION Mean sea level pressure (MSLP) gradients are one important factor that forecasters have to look at when forecasting surface winds in southern California. Forecasters at the National Weather Service Forecast Office in Oxnard, CA regularly use MSLP differences between Automated Surface Observing System (ASOS) stations to diagnose these MSLP gradients and forecast surface winds. Forecasters at the Oxnard office have suspected that a strong offshore MSLP difference between Bakersfield (BFL) and Santa Barbara (SBA) is associated with gusty and damaging northeast winds in the hills above Montecito (See Fig.
    [Show full text]