Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 251025
SPC MCD 251025
Mesoscale Discussion 0329
NWS Storm Prediction Center Norman OK
0525 AM CDT Sat Mar 25 2017
Areas affected...Parts of coastal southeast TX and western LA
Concerning...Severe potential...Watch unlikely
Valid 251025Z - 251230Z
Probability of Watch Issuance...20 percent
SUMMARY...Mainly an isolated strong to damaging wind threat could
develop with thunderstorms forming along a cold front this morning.
Watch issuance is unlikely.
DISCUSSION...10Z surface observations depict a southeastward-moving
cold front extending across east TX from an area of low pressure in
eastern OK/northwestern AR. Radar and IR satellite trends have shown
convective development beginning along the front since 09Z, mainly
just north/northwest of the Houston metro thus far. Additional
development along much of the length of the cold front may occur
through 12Z as this front encounters an unstable airmass across
parts of coastal southeast TX and western LA. Although parts of this
region experienced convective overturning earlier tonight, modestly
steep mid-level lapse rates and a moist low-level airmass are
contributing to MLCAPE generally ranging from 500 to 1500 J/kg ahead
of the front. Mid-level winds are not overly strong across most of
east TX (30-40 kt), with short-term guidance indicating mid-level
jet cores located to the north and south of this area. Low-level
winds have also generally veered to southwesterly as a low-level jet
across the lower MS Valley continues to shift away from the region.
Regardless, the expected combination of weak to moderate instability
and marginal shear should support some isolated strong/damaging wind
risk and perhaps some hail with the line of thunderstorms as it
moves southeastward to the coast this morning.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 29639670 30019613 30569507 31409384 31409332 31109295
30759267 30189290 29699365 29379459 28859532 28739568