Mesoscale Discussion 0098
NWS Storm Prediction Center Norman OK
1200 AM CST Sun Feb 25 2018
Areas affected...Texas coastal plain
Concerning...Severe potential...Watch unlikely
Valid 250600Z - 250730Z
Probability of Watch Issuance...5 percent
SUMMARY...Some thunderstorm activity developing across the region
could become fairly strong through the 2-4 AM CST time frame.
Overall, though, the severe weather potential seems limited, and a
watch is not currently anticipated.
DISCUSSION...Scattered thunderstorm development is underway near and
ahead of the weak surface front advancing into the Texas coastal
plain. This is being aided by forcing for ascent associated with
another low-amplitude short wave impulse crossing the lower Rio
Grande Valley, within the subtropical westerlies. Although
southerly low-level flow across the region is generally modest, with
speeds up to 30 kt generally confined to upper Texas coastal areas,
deep layer shear is strong. With layers of modestly steep lower/mid
tropospheric lapse rates contributing to CAPE up to around 1000 J/kg
(for moist boundary layer parcels with dew points in the upper 60s
to near 70), some of these storms could be accompanied by some risk
for severe hail into the 07-09Z time frame. Eventually, upscale
convective growth is possible along and just ahead of the front. As
this occurs, the risk for hail probably will decrease, but a few
locally strong wind gusts may accompany developing outflow.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 29389792 29819689 30329548 30699453 30749369 29739370
29199540 28219685 28179780 29389792