Tuesday, January 29, 2008

The Following, Six Posts, Are From Archived Chases Beginning In The Year 2005 And Concluding In The Year 2007


FO AND F2 RATED (MAF/NWS) TORNADO, SOUTHEASTERN BORDEN COUNTY, TEXAS, JUNE 2005

The first Image was taken in eastern Dawson County on SH 180, near SH 87 intersection, looking east/south/east toward Borden County at a developing "Tail-End Charlie" Storm Tower apart of a larger multi-cell complex but separated. My youngest daughter and I chose this cell to chase because of its position although stronger mature cells from a distant complex, north, existed at the time. Approximately 8 miles east of the townsite of Gail, in Borden County, on SH 180, looking to the south, we took the next digital image of a conical descending Wall Cloud as marble size hail began to fall from the RFD. We turned down the caliche road as indicated in photo and drove several miles south and took the third image of the first indication of a small tubular vortex beginning to descend with hail still originating aloft over the viewed updraft circulation but transported counterclockwise over us and on the northwestern side of the Wall Cloud.

The fourth image was taken only moments later as the tornado touched down, as noted from debris cloud on surface. The fifth image became obscure at the base of the tornado, although it may have retreated slightly, due to hail and rain cascading from the RFD as it neared the vortex. The sixth image is taken as driving back toward Gail, on SH 180, approximately 3-4 miles east of Gail looking south at intensifying tornado. This small Supercell was almost stationary with little movement noted and later seemed to have a retrograde movement toward the southwest. The final image is from MAF NWS WSR-88D radar (composite reflectivity), courtesy of the NWS at MAF "Dust Devil Dispatch" newsletter. As a side note the author called his oldest daughter, meteorologist at a Midland/Odessa news station, and provided "ground truth" conformation of the visual sighting with VIPIR radar display(s) which was detecting low-level circulation within the BWER. Below the radar image the author has attached two digital photographs of the tornado as it apparently intensified, based on visual larger cone-shaped size, as captured on FM 669 near the Borden/Howard Countly line looking east. An F2 rated tornado survey by MAF NWS, as shown on last attachment, and determined to have occured later in time than the author was present is suggestive of the southwest retrograde direction of this small Mesocyclone. The last graphic is also from the NWS at MAF "Dust Devil Dispatch" newsletter.




Sunday, January 27, 2008

Genesis of Patricia,TX Tornadic Classic Supercell, May 5th, 2006









The following digital images were taken of a Classic Supercell which originated in south central Gaines county and continued a path across southwestern Dawson county through northwestern to southeastern Martin County Texas on May 5th, 2006. The first image is near the Gaines/Dawson county line on SH 115 looking northwest at developing updraft circulation and small inflow band. The storm is moving from left to right on photo. The second image was captured just west of the townsite of Patricia, TX on SH 115 looking NWN at sculptured updraft intake region, lowering Wall Cloud, and main Rain/Hail Core. The third image is just west of Patricia looking north at eastern center of updraft circulation and lowered Wall Cloud being undercut by intensifying RFD. The fourth image, very up close, is of eastern dissected rotating updraft intake area and Wall Cloud with Fractus Scud Clouds in foreground and intense "sculpturing" RFD. The fifth image is approximate "golf ball"size hail blown off of updraft intake area by strongly sheared winds aloft. The sixth image is viewed from north on SH 828, just east of Patricia, after relocating to the east, looking south at well developed Wall Cloud and Tornado, partially rain wrapped , storm is moving from right to left on photo. This Wall Cloud may be a second generated lowered updraft from previous images of occluding original updraft region. Another image of Tornado as it intensifies. The NWS in Midland rated the Tornado as F0, F1, and F2 during it's brief lifespan on ground. Traveling back down SH 349 toward Midland the next two images were captured which, first, show the asymmetrically downwind tilted Storm Tower and, lastly, an image of Mammatus Clouds beneath the anvil, as viewed from the southwest, nearing dusk.



LP to Classic Supercell Transition, Patricia,TX, June 2007










The transition from a LP to Classic Supercell was observed from 0-3 Z on June 3rd, 2007 just west of Patricia, TX. The first image, as viewed from southeast, shows early genesis of LP with saucer shaped Rain Free Cloud Base, slightly lowered updraft intake area with rotating Fractus Scud Cloud(s), and light precipitation. The second image reveals pronounced Wall Cloud lowering partially obscuring the RFD "Clear Slot". The third image is un-zoomed to show the gradual transition to Classic Supercell by denoting low level moisture transport from "Beavers Tail" (lower right), ragged slightly lowered Wall Cloud, and RFD "Clear Slot" with noted blowing dust to southwest. The fourth image is driving quickly to the south of circulation center (to the right on image) to become better positioned on southeast side of storm but encountered large 2.5" diameter hail as shown hitting pavement and strong RFD winds estimated at 55-60 knots shown by blowing dust in background. The last image is viewing the RFD (upper center) from the southwest side of Classic Supercell with heavy rain and hail core lower center and left.

Saturday, January 26, 2008

CG Lightning Highlighted Tail Cloud, HP Supercell, Ft Stockton, TX, April 2007



The first image is from WSR-88D base reflectivity radar at MAF showing right turning HP Supercell (WO cell) with well developed V-notch (north of interstate 10). At the time of this radar capture the author was at Interstate 20 but turned south on HWY 285 and captured the two photos of a highlighted Tail Cloud from CG lightening just northwest of Ft Stockton, Texas at 2215 Z, April 29, 2007.

Long Arcus Cloud Associated with Multi-Cell Complex, East of Pecos, TX, April 2007






The first image is WSR-88D base reflectivity radar from MAF /NWS, on April 29th, 2007 just before 2200 Z, capturing the N-S striking multi-cell complex with three embedded cells labeled T5,V2, and O7. The first photo is viewing the southern portion of Arcus Cloud complex toward cell O7. The second photo is viewing the northern portion of Arcus Cloud complex toward cell T5. Both photos were taken along Interstate 20, east of Pecos, as viewed from east looking west. Based on apparent detachment from parent Shelf Cloud this long Arcus Cloud is an outflow boundary Roll Cloud.

Tuesday, January 22, 2008

Tail Cloud Inflow Band and Rear Flank Downdraft Gust Front, Southwestern Ector County, TX, June 2007







Two images of an Inflow Band ingested by a HP Supercell cyclonic circulation (slightly descended wall cloud), captured in extreme southwestern Ector Co., Texas on June 3rd, 2007, approximate 2200 Z as viewed from ENE. The Rear Flank Downdraft gust front, in second image, is seen just to the left (horizontal blowing dust at surface) of the southern precipitation core advancing and beginning to wrap around the updraft region of the Rain Free Cloud Base. The last image is taken very close to beneath the updraft region looking southwest where strong Rear Flanking Downdraft and associated Gust Front is blowing dust from northwest to southeast. After retreating away from advancement of storm the circulation updraft region became obscurred by occlusion from RFD (rain wrapped)