Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 200213
SPC MCD 200213
Mesoscale Discussion 0192
NWS Storm Prediction Center Norman OK
0813 PM CST Sun Feb 19 2017
Areas affected...South Central Texas
Concerning...Severe Thunderstorm Watch 35...
Valid 200213Z - 200415Z
The severe weather threat for Severe Thunderstorm Watch 35
SUMMARY...Thunderstorms will spread across the remainder of ww35
over the next few hours. Large hail is the primary risk with
isolated embedded supercells, and locally damaging winds may
accompany bowing line segments.
DISCUSSION...Convection has steadily increased in areal coverage
over the western half of ww35 ahead of a well-defined upper vort
that is located south of the Big Bend region near 28N/104w. Latest
model guidance suggests height falls will overspread deep south TX
later tonight which appears to be partly responsible for southward
thunderstorm development to Zapata county in the Valley. While BRO
and CRP soundings are both capped this evening, seasonally high PW
exists across south TX with 14.8 g/kg observed at CRP. As the LLJ
increases ahead of this activity there is increasing confidence
thunderstorms will continue to propagate east. Given the observed
instability across this region there is some concern for isolated
hail/damaging winds into portions of Deep South TX. Will continue
to monitor the region immediately south of ww35 for possible ww.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 28220129 30230082 30239898 28239947 28220129