ZCZC SPCSWOMCD ALL ACUS11 KWNS 241253 SPC MCD 241253 LAZ000-MSZ000-241530- MESOSCALE DISCUSSION 0263 NWS STORM PREDICTION CENTER NORMAN OK 0753 AM CDT THU MAR 24 2016 AREAS AFFECTED...PORTIONS CENTRAL/SRN LA...SEWN MS. CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 241253Z - 241530Z PROBABILITY OF WATCH ISSUANCE...40 PERCENT SUMMARY...STRONGEST PART OF TSTM BAND THAT HAS PRODUCED SUB-SVR GUSTS ACROSS SE TX IS FCST TO PROCEED EWD OVER MAINLY SRN LA...WITH SOME INCREASE IN ORGANIZATION NOTED AND NWD EXTENSION POSSIBLE INTO SLOWLY DESTABILIZING ENVIRONMENT PRECONVECTIVE WAA REGIME. WW MAY BE REQUIRED IF ADDITIONAL ORGANIZATION TAKES PLACE. DISCUSSION...CLUSTER OF TSTMS THAT PRODUCED SVR GUSTS IN AUS AREA AROUND 07Z SINCE BECAME MORE POORLY ORGANIZED...YET STILL MAINTAINING SOME OF ITS ORIGINAL COLD POOL WHILE PRODUCING 30-45-KT GUSTS ACROSS PORTIONS HOU METRO AND SURROUNDING TERRITORY. THIS ACTIVITY THEN FIRMED UP SOMEWHAT INTO SQUALL LINE THAT EXTENDED AT 1230Z FROM NEAR BKB SWWD ACROSS SABINE PASS REGION...BUT SINCE HAS DISORGANIZED SLIGHTLY AGAIN. 12Z LCH RAOB APPEARS TO HAVE SAMPLED IMMEDIATE PRECONVECTIVE ENVIRONMENT REASONABLY WELL...WITH SFC DEW POINT 67 F AND 1.3-INCH PW SUPPORTING AROUND 600 J/KG MLCAPE. BUOYANCY DECREASES WITH NNEWD EXTENT AHEAD OF SQUALL LINE...AND INCREASES SWD OVER GULF...LARGELY COMMENSURATE WITH SFC THETAE. BOUNDARY-LAYER MOIST ADVECTION AND WAA JUST AHEAD OF THIS CONVECTION SHOULD MAINTAIN AT LEAST MRGLLY UNSTABLE ENVIRONMENT. MEANWHILE...BASE OF EML LAYER HAS BEEN LIFTED AND WEAKENED...EVIDENT IN COMPARISON OF 00Z AND 12Z LCH RAOBS...AND THAT PROCESS SHOULD CONTINUE IN NARROW ZONE JUST AHEAD OF CONVECTIVE BAND. THAT MAY BE RELATED PARTLY TO PASSAGE OF GRAVITY WAVE... APPARENT FOR LAST FEW HOURS IN REFLECTIVITY ANIMATIONS AND CONSISTENT SFC RESPONSES ABOUT 60-90 NM AHEAD OF CONVECTIVE BAND. WINDS HAVE TEMPORARILY WEAKENED AND/OR VEERED IMMEDIATELY BEHIND GRAVITY WAVE...AS SAMPLED BY THAT LCH RAOB AND BY EARLIER OBS. HOWEVER...SOME BACKING IS NOTED IN NARROW CORRIDOR BETWEEN THAT PROCESS AND CONVECTIVE BAND. ACCORDINGLY MODIFIED SOUNDING AND VWP DOES RESULT IN LOCALLY ENHANCED LOW-LEVEL SHEAR AND HODOGRAPH SIZES...DESPITE RATHER VEERED 850-MB FLOW...SUCH THAT 150-250 J/KG 0-1 KM SRH MAY BE AVAILABLE TO SOME PARTS OF CONVECTIVE BAND. 50-50-KT EFFECTIVE-SHEAR MAGNITUDES ALSO ARE APPARENT OVER AREA. AS SUCH...SMALL/SHORT-LIVED TORNADO OR TWO CANNOT BE RULED OUT WITH TRANSIENT MESO/MISO-CIRCULATIONS ALONG LEADING EDGE OF QLCS. HOWEVER...MAIN THREAT WILL BE DAMAGING GUSTS. LIMITING FACTOR MAY BE LACK OF MORE ROBUST INSTABILITY...WITH 1. ONLY LOW-MID-60S F DEW POINTS PRESENTLY APPARENT OVER MUCH OF INLAND AREA NEAR/N OF I-10 FARTHER E...AND 2. DENSE CLOUD COVER PER VIS IMAGERY THAT WILL IMPEDE DIABATIC HEATING. ..EDWARDS/DIAL.. 03/24/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JAN...LIX...LCH...SHV... LAT...LON 29739367 30729299 31279251 31419206 31449093 30579081 29809111 29259131 29419150 29379130 29519129 29519141 29519150 29649158 29629165 29499178 29499188 29579207 29539225 29599274 29779325 29739367 NNNN