Austin / Travis County and South Central Texas Weather Update #3
Prepared by UT University/Incident Meteorologist Troy Kimmel
310pm CT – Sunday / 28 May 2017
.. Authority NWS/Storm Prediction Center ..
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 293
NWS Storm Prediction Center Norman OK
310 PM CDT Sun May 28 2017
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Central and Southeast Texas
* Effective this Sunday afternoon and evening from 310 PM until
1000 PM CDT.
* Primary threats include...
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
Scattered damaging wind gusts to 70 mph possible
SUMMARY...Thunderstorms are expected to rapidly develop over the
watch area this afternoon, spreading slowly eastward this evening.
Damaging winds and hail will be possible in the strongest cells.
The severe thunderstorm watch area is approximately along and 60
statute miles either side of a line from 35 miles south southeast of
Del Rio TX to 65 miles north of Huntsville TX. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 292...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
25025.
...Hart
WATCH COUNTY NOTIFICATION FOR WATCH 293
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
310 PM CDT SUN MAY 28 2017
TXC013-019-021-029-031-053-055-091-123-127-137-149-163-171-177-
187-209-255-259-265-271-285-287-299-323-325-385-453-463-465-491-
493-507-290300-
/O.NEW.KEWX.SV.A.0293.170528T2010Z-170529T0300Z/
THE NATIONAL WEATHER SERVICE HAS ISSUED SEVERE THUNDERSTORM WATCH
293 IN EFFECT UNTIL 10 PM CDT THIS EVENING FOR THE FOLLOWING
AREAS
IN TEXAS THIS WATCH INCLUDES 33 COUNTIES
IN SOUTH CENTRAL TEXAS
ATASCOSA BANDERA BASTROP
BEXAR BLANCO BURNET
CALDWELL COMAL DEWITT
DIMMIT EDWARDS FAYETTE
FRIO GILLESPIE GONZALES
GUADALUPE HAYS KARNES
KENDALL KERR KINNEY
LAVACA LEE LLANO
MAVERICK MEDINA REAL
TRAVIS UVALDE VAL VERDE
WILLIAMSON WILSON ZAVALA
THIS INCLUDES THE CITIES OF AUSTIN, BANDERA, BASTROP, BLANCO,
BOERNE, BRACKETVILLE, BURNET, CARRIZO SPRINGS, CRYSTAL CITY,
CUERO, DEL RIO, EAGLE PASS, FLORESVILLE, FREDERICKSBURG,
GEORGETOWN, GIDDINGS, GONZALES, HALLETSVILLE, HONDO, KARNES CITY,
KERRVILLE, LA GRANGE, LEAKEY, LLANO, LOCKHART, NEW BRAUNFELS,
PEARSALL, PLEASANTON, ROCKSPRINGS, SAN ANTONIO, SAN MARCOS,
SEGUIN, AND UVALDE.
$$
—–
Austin / Travis County and South Central Texas Weather Update #2
Prepared by UT University/Incident Meteorologist Troy Kimmel
205pm CT – Sunday / 28 May 2017
.. Authority NWS/Storm Prediction Center ..
Mesoscale Discussion 0901
NWS Storm Prediction Center Norman OK
0134 PM CDT Sun May 28 2017
Areas affected...Central Texas
Concerning...Severe potential...Watch likely
Valid 281834Z - 281930Z
Probability of Watch Issuance...80 percent
SUMMARY...A severe weather watch seems probable at some point late
this afternoon and evening, perhaps as early as 20-21Z.
DISCUSSION...Objective analysis indicates that insolation within a
boundary layer characterized by high moisture content (lower/mid 70s
F surface dew points) is contributing to strong/extreme CAPE on the
order of 4000+ J/kg across much of the region, including the
Interstate 35 corridor between San Antonio and Waco. Mid-level
inhibition beneath warm elevated mixed layer air does still appear
considerable, particularly given weak, or at least unclear,
mid/upper forcing for ascent. An area of enhanced ascent
contributing to deepening mid-level based convection near the
Interstate 20 corridor, west of the Dallas/Fort Worth metroplex, may
remain displaced to the north of an area of sustained enhanced
low-level convergence near the Waco area. This is near the
intersection of a surface front that extends southwestward into the
Rio Grande Valley, to the west of Del Rio, and the western flank of
composite outflow from extensive overnight convection, now advancing
into the north central Gulf Coast.
However, the latest Rapid Refresh suggests that additional surface
heating, coupled with subtle mid-level height falls on the southern
fringe of the westerlies, may be sufficient to support the
initiation of thunderstorms as early as 20-21Z. Once this does
occur, intensification likely will be very rapid, and deep layer
shear appears sufficient for the evolution of supercell structures
with large hail and perhaps an isolated tornado, in addition to
strong downbursts accompanied by potentially damaging surface gusts.
..Kerr/Hart.. 05/28/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...HGX...FWD...EWX...SJT...
LAT...LON 30359938 31149852 31689787 31949702 31599588 30929570
30419690 29639779 29409830 29329912 30359938