ZCZC SPCSWOMCD ALL ACUS11 KWNS 090025 SPC MCD 090025 TXZ000-090300- MESOSCALE DISCUSSION 0190 NWS STORM PREDICTION CENTER NORMAN OK 0625 PM CST TUE MAR 08 2016 AREAS AFFECTED...PORTIONS SW TX...SRN HILL COUNTRY AND LOWER-MIDDLE RIO GRANDE VALLEY REGION. CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 090025Z - 090300Z PROBABILITY OF WATCH ISSUANCE...40 PERCENT SUMMARY...PRECIP/CONVECTIVE COVERAGE AND ACCOMPANYING SVR POTENTIAL ARE FCST TO INCREASE GRADUALLY OVER THIS REGION THROUGH EVENING. WHILE THREAT APPEARS SOMEWHAT MRGL/ISOLATED FOR WW NEXT 1-2 HOURS...WW MAY BE REQUIRED AT SOME POINT THIS EVENING. DISCUSSION...00Z SFC MESOANALYSIS SHOWED OUTFLOW BOUNDARY -- LEFT OVER FROM EARLY-DAY MCS -- FROM NEAR OCH...HLR...NRN GILLESPIE COUNTY...TO CENTRAL VAL VERDE COUNTY...WHERE IT INTERSECTED DRYLINE. DRYLINE EXTENDED FROM THERE SSEWD BETWEEN FTN-COT...TO ERN ZAPATA COUNTY THEN SWD OVER MEX. BASED ON ITS PRESENTATION IS VIS IMAGERY...OUTFLOW BOUNDARY HAS BECOME QUASISTATIONARY AND MAY BE RETREATING NWWD IN SOME LOCALES. MID/UPPER-LEVEL CYCLONE -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER NWRN MEX -- IS EXPECTED TO PROCEED SEWD OBLIQUELY TOWARD THIS REGION. ASSOCIATED LOW/MIDDLE-LEVEL HEIGHT FALLS...AND BROAD/PATCHY SFC PRESSURE FALLS ALREADY ARE EVIDENT OVER THIS AREA. EXPECT WEAK MOIST ADVECTION ACROSS THIS CORRIDOR W OF PRIMARY EVENING LLJ THAT IS EXPECTED TO DEVELOP OVER E TX AND LA...AMIDST CONTINUED ISALLOBARIC FORCING. DRYLINE SHOULD RETREAT NWWD WITH DEW POINTS CONTINUING TO RISE ACROSS CURRENTLY WELL-MIXED AREAS OF RIO GRANDE VALLEY. TSTMS ARE BUILDING ATOP DEEPLY MIXED BOUNDARY LAYER...W OF DRYLINE AND OVER NERN MEX FROM FTN AREA SSEWD TO ABOUT 75 W MFE...NRN PORTION OF WHICH LIKELY WAS SAMPLED BY 00Z DRT RAOB. THIS ACTIVITY SHOULD ENCOUNTER INCREASING MOISTURE ACROSS S TX AS DRYLINE RETREATS...BUT ALSO...STRONGER MLCINH WITH EWD EXTENT RELATED TO PLUME OF EML-RELATED MLCINH OVER S TX THAT WAS SAMPLED WELL BY 00Z CRP SOUNDING. EML SHOULD BE WEAKENED SLOWLY WITH TIME AS LOW-LEVEL THETAE INCREASES AND AS MIDLEVEL UVV GRADUALLY STRENGTHENS. ACTIVITY CROSSING OUTFLOW BOUNDARY MAY TEMPORARILY BOOST SVR RISK WHILE ENCOUNTERING ASSOCIATED LIFT/VORTICITY...EITHER BECOMING ELEVATED AND OFFERING HAIL THREAT OR WEAKENING. WARM-SECTOR CONVECTION WILL REMAIN POORLY FOCUSED WITH SPORADIC...ISOLATED RISK FOR DAMAGING GUSTS AND LARGE HAIL GIVEN PRESENCE OF LARGE BUOYANCY -- MLCAPE 2000-3500 J/KG MLCAPE -- AMIDST GENERALLY 45-55 KT EFFECTIVE-SHEAR MAGNITUDE. WITH TIME...AS CONVECTIVE COVERAGE AND AVBL MOISTURE EACH INCREASE...SO WILL DENSITY AND INTENSITY OF SVR THREAT. ..EDWARDS/THOMPSON.. 03/09/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CRP...EWX...BRO...MAF... LAT...LON 26419909 26499911 26549919 26849926 26909938 27059947 27279943 27339957 27469944 27609953 27679974 27989996 28270028 28900063 29100066 29160078 29310084 29390096 29460109 29520125 29620120 29600136 29710134 29790144 29810176 30010135 30249985 30219915 28689870 27769845 26829814 26189848 26229865 26359884 26419909 NNNN