000
ACUS11 KWNS 200128
SWOMCD
SPC MCD 200128
TXZ000-200300-

MESOSCALE DISCUSSION 2179
NWS STORM PREDICTION CENTER NORMAN OK
0728 PM CST THU NOV 19 2009

AREAS AFFECTED...PARTS OF S TX AND THE LOWER TX COAST

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 200128Z - 200300Z

THE THREAT FOR ISOLATED SEVERE STORMS...INCLUDING EPISODIC SUPERCELL
STRUCTURES...IS EXPECTED TO CONTINUE ACROSS REGION TONIGHT.  A WW IS
NOT CURRENTLY ANTICIPATED.

TSTMS CONTINUE TO INCREASE IN COVERAGE AND INTENSITY THIS EVENING
OVER THE LOWER TX COAST WITHIN STRENGTHENING WWA REGIME ASSOCIATED
WITH MIDLEVEL TROUGH APPROACHING FROM THE W.  AS OF 0117Z...CRP
RADAR DATA INDICATED A STORM EXHIBITING SUPERCELL CHARACTERISTICS
OVER CORPUS CHRISTI BAY ALONG THE SRN FRINGE OF A LARGER COMPLEX OF
STORMS.  AS MENTIONED IN 01Z OUTLOOK...AIR MASS IS RATHER MOIST
WHICH SHOULD MAINTAIN AT LEAST A MARGINALLY UNSTABLE ENVIRONMENT
OVERNIGHT WITH MLCAPE OF LESS THAN 1000 J/KG.

LATEST TRENDS IN CRP VWP DO INDICATE SOME INCREASE IN LOW-LEVEL
WINDS WHICH IS RESULTING IN AN ENVIRONMENT FAVORABLE FOR UPDRAFT
ROTATION.  AS SUCH...THE POTENTIAL WILL EXIST FOR TRANSIENT
SUPERCELL STRUCTURES CAPABLE OF ISOLATED SEVERE WEATHER. IT APPEARS
THAT A MORE WIDESPREAD SEVERE WEATHER EPISODE WILL LIKELY BE LIMITED
BY THE WEAK LOW-LEVEL LAPSE RATES AND MARGINAL CONVECTIVE
INSTABILITY...AND THUS A WW IS NOT CURRENTLY ANTICIPATED.

..MEAD.. 11/20/2009

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...HGX...CRP...EWX...BRO...

LAT...LON   27279724 27169817 27929850 28849834 29249781 29279712
            29069644 28529609 27759650 27279724