The Lagrange Torando During Vortex2. Part Ii: Photogrammetry Analysis of the Tornado Combined with Dual-Doppler Radar Data
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A Study of Synoptic-Scale Tornado Regimes
Garner, J. M., 2013: A study of synoptic-scale tornado regimes. Electronic J. Severe Storms Meteor., 8 (3), 1–25. A Study of Synoptic-Scale Tornado Regimes JONATHAN M. GARNER NOAA/NWS/Storm Prediction Center, Norman, OK (Submitted 21 November 2012; in final form 06 August 2013) ABSTRACT The significant tornado parameter (STP) has been used by severe-thunderstorm forecasters since 2003 to identify environments favoring development of strong to violent tornadoes. The STP and its individual components of mixed-layer (ML) CAPE, 0–6-km bulk wind difference (BWD), 0–1-km storm-relative helicity (SRH), and ML lifted condensation level (LCL) have been calculated here using archived surface objective analysis data, and then examined during the period 2003−2010 over the central and eastern United States. These components then were compared and contrasted in order to distinguish between environmental characteristics analyzed for three different synoptic-cyclone regimes that produced significantly tornadic supercells: cold fronts, warm fronts, and drylines. Results show that MLCAPE contributes strongly to the dryline significant-tornado environment, while it was less pronounced in cold- frontal significant-tornado regimes. The 0–6-km BWD was found to contribute equally to all three significant tornado regimes, while 0–1-km SRH more strongly contributed to the cold-frontal significant- tornado environment than for the warm-frontal and dryline regimes. –––––––––––––––––––––––– 1. Background and motivation As detailed in Hobbs et al. (1996), synoptic- scale cyclones that foster tornado development Parameter-based and pattern-recognition evolve with time as they emerge over the central forecast techniques have been essential and eastern contiguous United States (hereafter, components of anticipating tornadoes in the CONUS). -
Soaring Weather
Chapter 16 SOARING WEATHER While horse racing may be the "Sport of Kings," of the craft depends on the weather and the skill soaring may be considered the "King of Sports." of the pilot. Forward thrust comes from gliding Soaring bears the relationship to flying that sailing downward relative to the air the same as thrust bears to power boating. Soaring has made notable is developed in a power-off glide by a conven contributions to meteorology. For example, soar tional aircraft. Therefore, to gain or maintain ing pilots have probed thunderstorms and moun altitude, the soaring pilot must rely on upward tain waves with findings that have made flying motion of the air. safer for all pilots. However, soaring is primarily To a sailplane pilot, "lift" means the rate of recreational. climb he can achieve in an up-current, while "sink" A sailplane must have auxiliary power to be denotes his rate of descent in a downdraft or in come airborne such as a winch, a ground tow, or neutral air. "Zero sink" means that upward cur a tow by a powered aircraft. Once the sailcraft is rents are just strong enough to enable him to hold airborne and the tow cable released, performance altitude but not to climb. Sailplanes are highly 171 r efficient machines; a sink rate of a mere 2 feet per second. There is no point in trying to soar until second provides an airspeed of about 40 knots, and weather conditions favor vertical speeds greater a sink rate of 6 feet per second gives an airspeed than the minimum sink rate of the aircraft. -
Tornadoes & Funnel Clouds Fake Tornado
NOAA’s National Weather Service Basic Concepts of Severe Storm Spotting 2009 – Rusty Kapela Milwaukee/Sullivan weather.gov/milwaukee Housekeeping Duties • How many new spotters? - if this is your first spotter class & you intend to be a spotter – please raise your hands. • A basic spotter class slide set & an advanced spotter slide set can be found on the Storm Spotter Page on the Milwaukee/Sullivan web site (handout). • Utilize search engines and You Tube to find storm videos and other material. Class Agenda • 1) Why we are here • 2) National Weather Service Structure & Role • 3) Role of Spotters • 4) Types of reports needed from spotters • 5) Thunderstorm structure • 6) Shelf clouds & rotating wall clouds • 7) You earn your “Learner’s Permit” Thunderstorm Structure Those two cloud features you were wondering about… Storm Movement Shelf Cloud Rotating Wall Cloud Rain, Hail, Downburst winds Tornadoes & Funnel Clouds Fake Tornado It’s not rotating & no damage! Let’s Get Started! Video Why are we here? Parsons Manufacturing 120-140 employees inside July 13, 2004 Roanoke, IL Storm shelters F4 Tornado – no injuries or deaths. They have trained spotters with 2-way radios Why Are We Here? National Weather Service’s role – Issue warnings & provide training Spotter’s role – Provide ground-truth reports and observations We need (more) spotters!! National Weather Service Structure & Role • Federal Government • Department of Commerce • National Oceanic & Atmospheric Administration • National Weather Service 122 Field Offices, 6 Regional, 13 River Forecast Centers, Headquarters, other specialty centers Mission – issue forecasts and warnings to minimize the loss of life & property National Weather Service Forecast Office - Milwaukee/Sullivan Watch/Warning responsibility for 20 counties in southeast and south- central Wisconsin. -
More Observations of Small Funnel Clouds and Other Tubular Clouds
3714 MONTHLY WEATHER REVIEW VOLUME 133 PICTURE OF THE MONTH More Observations of Small Funnel Clouds and Other Tubular Clouds HOWARD B. BLUESTEIN School of Meteorology, University of Oklahoma, Norman, Oklahoma (Manuscript received 14 March 2005, in final form 20 May 2005) ABSTRACT In this brief contribution, photographic documentation is provided of a variety of small, tubular-shaped clouds and of a small funnel cloud pendant from a convective cloud that appears to have been modified by flow over high-altitude mountains in northeast Colorado. These funnel clouds are contrasted with others that have been documented, including those pendant from high-based cumulus clouds in the plains of the United States. It is suggested that the mountain funnel cloud is unique in that flow over high terrain is probably responsible for its existence; other types of small funnel clouds are seen both over elevated, mountainous terrain and over flat terrain at lower elevations. 1. Introduction which the benign funnel clouds occur so that if they are observed, severe weather warnings are not issued. Fur- Bluestein (1994) and others (e.g., Doswell 1985, p. thermore, the small funnel clouds are of interest in their 107; McCaul and Blanchard 1990) have documented, in own right because their dynamics are not well under- the plains of the United States, small funnel clouds pen- stood, and they have not been discussed in the litera- dant from convective clouds whose updrafts appear to ture to the much greater extent that the dynamics of be rooted above the boundary layer. Above many of tornadoes have (e.g., Davies-Jones 1986). -
June 18, 2017 Landspout Tornadoes
June 18, 2017 Landspout Tornadoes During the evening hours of Sunday, June 18, thunderstorms developed in the vicinity of a cold front over Reagan and Upton Counties.As a result of intense heating and an incredible amount of instability along this boundary, three EF0 landspout* (see definitionat bottom of report) tornadoes touched down in Reagan and southeast Upton Counties between 7 and 8 pm CDT. These tornadoes occurred in open country and no damage was reported. Tornado #1 – EF0: Southwest Reagan County to Southeast Upton County (~7:05-7:13 pm CDT) The first thunderstorm developed around 6:00 pm near Big Lake, TX and slowly moved west along and near US Hwy 67. Law enforcement officersand folks in the area viewed and took images of a tornado that developed 1-2 miles south of US Hwy 67 roughly 14 miles east of Big Lake and continued westward through open fields insouth east portions of Upton County. The tornado was narrow, perhaps 50-75 yards in width and no damage was reported with this tornado. Photo by Maybell Carrasco Photo by Greg Romero Tornado #2 – EF0: Central Reagan Photo by Shanna Gibson County (~8:00 pm CDT) Another thunderstorm moving west, entered eastern Reagan County around 7:30 pm. As this storm approached Big Lake, a second tornado was spotted around 8 pm roughly 6-7 miles northeast of Big Lake, 2-3 miles east of SH 137. This tornado was very short-lived and went undetected on radar. It occurred in open country and no damage was reported. Tornado #3 – EF0: Northeast Reagan County – approximately 20-25 miles north of Big Lake. -
The Unnamed Atlantic Tropical Storms of 1970
944 MONTHLY WEATHER REVIEW Vol. 99, No. 12 UDC 551.515.23:661.507.35!2:551.607.362.2(261) “1970.08-.lo” THE UNNAMED ATLANTIC TROPICAL STORMS OF 1970 DAVID B. SPIEGLER Allied Research Associates, Inc., Concord, Mass. ABSTRACT A detailed analysis of conventional and aircraft reconnaissance data and satellite pictures for two unnamed Atlantic Ocean cyclones during 1970 indicates that the stqrms were of tropical nature and were probably of at least minimal hurricane intensity for part of their life history. Prior to becoming a hurricane, one of the storms exhibited characteristics not typical of any of the recognized classical cyclone types [i.e., tropical, extratropical, and subtropical (Kona)]. The implications of this are discussed and the concept of semitropical cyclones as a separate cyclone category is advanced. 6. INTRODUCTION ing recognition of hybrid-type storms provides additional support for the recommendation. During the 1970 tropical cyclone season, tn7o storms occurred that were not given names at the time. The 2. UNNAMED STORM NO. I-AUG. Q3-$8, 6970 National Hurricane Center (NHC) monitored their prog- ress and issued bulletins throughout their life history but A mell-organized tropical disturbance noted on satellite they mere not officially recognized as tropical cyclones of pictures during August 8, south of the Cape Verde Islands tropical storm or hurricane intensity. In their annual post- in the far eastern tropical Atlantic, intensified to ti strong season summary of the hurricane season, NHC discusses depression as it moved westmarcl. On Thursday, August 13, these storms in some detail (Simpson and Pelissier 1971) some further intensification of the system appeared to be but thej- are not presently included in the official list of taking place while the depression was about 250 mi 1970 tropical storms. -
Skip Talbot Photography by Jennifer Brindley
STORM SPOTTING Skip Talbot SECRETS Photography by Jennifer Brindley Ubl and others Topics • Supercell Visualization • Radar Presentation • Structure Identification • Storm Properties • Walk Through Disclaimers • Attend spotter training • Your safety is more important than spotting, photos, video, or tornado reports Supercell Visualization Lemon and Doswell 1979 Supercell Visualization Supercell Visualization Photo: Chris Gullikson Supercell Visualization Photo: Chris Gullikson Anvil Anvil Backshear Mammatus Cumulonimbus Flanking Line Cloud Base Striations Precipitation Wall Cloud Precipitation-free Base Supercell Visualization Radar Presentation Classic Hook Echo Radar Presentation Android / iOS Android Windows GrLevel3 / GrLevel2 Radar Presentation Classic Hook Echo Radar Presentation Radar Presentation Radar Presentation Radar Presentation Storm Spotting Zoo • Bear’s Cage • Whale’s Mouth • Beaver Tail • Horseshoe • Ghost Train Base (Updraft Base) (Rain Free Base or RFB) Base (Updraft Base) (Rain Free Base or RFB) Base (Updraft Base) (Rain Free Base or RFB) Base (Updraft Base) (Rain Free Base or RFB) Base (Updraft Base) (Rain Free Base or RFB) Base (Updraft Base) (Rain Free Base or RFB) Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe Horseshoe - Cyclical supercell with multiple tornadoes HorseshoeHorseshoe HorseshoeHorseshoe Horseshoe Horseshoe – Anticyclonic Funnel Horseshoe Horseshoe – Anticyclonic Funnel Horseshoe - No Wall Cloud Horseshoe - No Wall Cloud -
Meteorology – Lecture 19
Meteorology – Lecture 19 Robert Fovell [email protected] 1 Important notes • These slides show some figures and videos prepared by Robert G. Fovell (RGF) for his “Meteorology” course, published by The Great Courses (TGC). Unless otherwise identified, they were created by RGF. • In some cases, the figures employed in the course video are different from what I present here, but these were the figures I provided to TGC at the time the course was taped. • These figures are intended to supplement the videos, in order to facilitate understanding of the concepts discussed in the course. These slide shows cannot, and are not intended to, replace the course itself and are not expected to be understandable in isolation. • Accordingly, these presentations do not represent a summary of each lecture, and neither do they contain each lecture’s full content. 2 Animations linked in the PowerPoint version of these slides may also be found here: http://people.atmos.ucla.edu/fovell/meteo/ 3 Mesoscale convective systems (MCSs) and drylines 4 This map shows a dryline that formed in Texas during April 2000. The dryline is indicated by unfilled half-circles in orange, pointing at the more moist air. We see little T contrast but very large TD change. Dew points drop from 68F to 29F -- huge decrease in humidity 5 Animation 6 Supercell thunderstorms 7 The secret ingredient for supercells is large amounts of vertical wind shear. CAPE is necessary but sufficient shear is essential. It is shear that makes the difference between an ordinary multicellular thunderstorm and the rotating supercell. The shear implies rotation. -
Mid-Latitude Dynamics and Atmospheric Rivers Session: Theory, Structure, Processes 1 Jason M
Mid-Latitude Dynamics and Atmospheric Rivers Session: Theory, Structure, Processes 1 Jason M. Cordeira Wednesday, 10 August 2016 Plymouth State University, CW3E/Scripps Contribution from: Heini Werni Peter Knippertz Harold Sodemann Andreas Stohl Francina Dominguez Huancui Hu 2016 International Atmospheric Rivers Conference 8–11 August 2016 Scripps Institution of Oceanography Objective and Outline Objective • What components of midlatitude circulation support formation and structure of atmospheric rivers? Outline • Part 1: ARs, midlatitude storm track, and cyclogenesis • Part 2: ARs, tropical moisture exports, and warm conveyor belt Objective and Outline Objective • What components of midlatitude circulation support formation and structure of atmospheric rivers? Outline • Part 1: ARs, midlatitude storm track, and cyclogenesis • Part 2: ARs, tropical moisture exports, and warm conveyor belt Mimic TPW (SSEC/Wisconsin) • Global water vapor distribution is concentrated at lower latitudes owing to warmer temperatures • Observations illustrate poleward extrusions of water vapor along “tropospheric rivers” or “atmospheric rivers” Zhu and Newell (MWR-1998) • >90% of meridional water vapor transports occurs along ARs • ARs part of midlatitude cyclones and move with storm track Climatology of Water Vapor Transport Global mean IVT 150 kg m−1 s−1 • ECMWF ERA Interim Reanalysis • Oct–Mar 99/00 to 08/09 (i.e., ten winters) • IVT calculated for isobaric layers between 1000 and 100 hPa Tropical–Extratropical Interactions Waugh and Fanutso (2003-JAS) Knippertz -
ESSENTIALS of METEOROLOGY (7Th Ed.) GLOSSARY
ESSENTIALS OF METEOROLOGY (7th ed.) GLOSSARY Chapter 1 Aerosols Tiny suspended solid particles (dust, smoke, etc.) or liquid droplets that enter the atmosphere from either natural or human (anthropogenic) sources, such as the burning of fossil fuels. Sulfur-containing fossil fuels, such as coal, produce sulfate aerosols. Air density The ratio of the mass of a substance to the volume occupied by it. Air density is usually expressed as g/cm3 or kg/m3. Also See Density. Air pressure The pressure exerted by the mass of air above a given point, usually expressed in millibars (mb), inches of (atmospheric mercury (Hg) or in hectopascals (hPa). pressure) Atmosphere The envelope of gases that surround a planet and are held to it by the planet's gravitational attraction. The earth's atmosphere is mainly nitrogen and oxygen. Carbon dioxide (CO2) A colorless, odorless gas whose concentration is about 0.039 percent (390 ppm) in a volume of air near sea level. It is a selective absorber of infrared radiation and, consequently, it is important in the earth's atmospheric greenhouse effect. Solid CO2 is called dry ice. Climate The accumulation of daily and seasonal weather events over a long period of time. Front The transition zone between two distinct air masses. Hurricane A tropical cyclone having winds in excess of 64 knots (74 mi/hr). Ionosphere An electrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist. Lapse rate The rate at which an atmospheric variable (usually temperature) decreases with height. (See Environmental lapse rate.) Mesosphere The atmospheric layer between the stratosphere and the thermosphere. -
Tornadogenesis in a Simulated Mesovortex Within a Mesoscale Convective System
3372 JOURNAL OF THE ATMOSPHERIC SCIENCES VOLUME 69 Tornadogenesis in a Simulated Mesovortex within a Mesoscale Convective System ALEXANDER D. SCHENKMAN,MING XUE, AND ALAN SHAPIRO Center for Analysis and Prediction of Storms, and School of Meteorology, University of Oklahoma, Norman, Oklahoma (Manuscript received 3 February 2012, in final form 23 April 2012) ABSTRACT The Advanced Regional Prediction System (ARPS) is used to simulate a tornadic mesovortex with the aim of understanding the associated tornadogenesis processes. The mesovortex was one of two tornadic meso- vortices spawned by a mesoscale convective system (MCS) that traversed southwestern and central Okla- homa on 8–9 May 2007. The simulation used 100-m horizontal grid spacing, and is nested within two outer grids with 400-m and 2-km grid spacing, respectively. Both outer grids assimilate radar, upper-air, and surface observations via 5-min three-dimensional variational data assimilation (3DVAR) cycles. The 100-m grid is initialized from a 40-min forecast on the 400-m grid. Results from the 100-m simulation provide a detailed picture of the development of a mesovortex that produces a submesovortex-scale tornado-like vortex (TLV). Closer examination of the genesis of the TLV suggests that a strong low-level updraft is critical in converging and amplifying vertical vorticity associated with the mesovortex. Vertical cross sections and backward trajectory analyses from this low-level updraft reveal that the updraft is the upward branch of a strong rotor that forms just northwest of the simulated TLV. The horizontal vorticity in this rotor originates in the near-surface inflow and is caused by surface friction. -
Central Region Technical Attachment 95-08 Examination of an Apparent
CRH SSD APRIL 1995 CENTRAL REGION TECHNICAL ATTACHMENT 95-08 EXAMINATION OF AN APPARENT LANDSPOUT IN THE EASTERN BLACK HILLS OF WESTERN SOUTH DAKOTA David L. Hintz1 and Matthew J. Bunkers National Weather Service Office Rapid City, South Dakota 1. Abstract On June 29, 1994, an apparent landspout occurred in the Black Hills of South Dakota. This landspout exhibited most of the features characteristic of traditional landspouts documented in eastern Colorado. The landspout lasted 3 to 8 minutes, had a width of less than 20 m and a path of 1 to 3 km, produced estimated wind speeds of Fl intensity (33 to 50 m s1), and emanated from a towering cumulus (TCU) cloud located along a quasi-stationary convergencq/cyclonic shear zone. No radar echo was observed with this event; however, a supercell thunderstorm was located 80-100 km to the east. National Weather Service meteorologists surveyed the “very localized” damage area and ruled out the possibility of the landspout being related to microburst, gustnado, or dust devil activity, as winds away from the landspout were less than 3 m s1. The landspout apparently “detached” from the parent TCU and damaged a farm which resulted in $1,000 dollars in expenses. 2. Introduction During the late 1980’s and early 1990’s researchers documented a phe nomenon with subtle differences from traditional tornadoes and waterspouts, herein referred to as the landspout (Seargent 1994; Brady and Szoke 1988, 1989; Bluestein 1985). The term “landspout” was actually coined by Bluestein (I985)(in the formal literature) when he observed this type of vortex along an Oklahoma squall line.