ZCZC SPCSWOMCD ALL ACUS11 KWNS 161657 SPC MCD 161657 OKZ000-TXZ000-161900- MESOSCALE DISCUSSION 0658 NWS STORM PREDICTION CENTER NORMAN OK 1157 AM CDT SAT MAY 16 2015 AREAS AFFECTED...SRN TX PANHANDLE...TX SOUTH PLAINS...W-CNTRL TX...SWRN OK CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 161657Z - 161900Z PROBABILITY OF WATCH ISSUANCE...80 PERCENT SUMMARY...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY ACROSS THE SRN TX PANHANDLE/SOUTH PLAINS INTO W-CNTRL TX AND SWRN OK. THE POTENTIAL FOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL...DMGG WIND GUSTS...AND A COUPLE TORNADOES WILL INCREASE...AND A TORNADO WATCH WILL LIKELY BE ISSUED WITHIN THE NEXT 1-2 HRS. DISCUSSION...THE SVR THREAT IS EXPECTED TO RAPIDLY INCREASE THROUGHOUT THE EARLY AFTERNOON ACROSS THE SRN TX PANHANDLE AND S PLAINS INTO W-CNTRL TX. THE LEADING EDGE OF STRONGER FORCING FOR ASCENT APPEARS TO BE DEMARCATED BY CONVECTION OVER NERN NM /E OF LVS/...BUT SATELLITE/RADAR TRENDS SHOW ADDITIONAL AREAS OF TSTM INITIATION OCCURRING W OF LBB ALONG A REMNANT OUTFLOW BOUNDARY...WITH ANOTHER OUTFLOW BOUNDARY REINFORCED BY MORE RECENT CONVECTION DRAPED ACROSS THE SRN TX PANHANDLE. MID-LEVEL CONVECTION WAS MORE PREVALENT FARTHER S TOWARDS BPG...BUT MAY EVENTUALLY EVOLVE INTO SFC-BASED TSTMS. VERY RICH MOISTURE ACROSS THE REGION AMIDST STEEPENING MIDLEVEL LAPSE RATES /SAMPLED BY 12Z MAF SOUNDING/ SHOULD RESULT IN MLCAPE VALUES APPROACHING 3000 J/KG THIS AFTERNOON...AMIDST AMPLE DEEP-LAYER SHEAR SUFFICIENT FOR SUPERCELLS. A CONSOLIDATING DRYLINE WILL SHIFT THE PRIMARY SVR THREAT INTO CNTRL/ERN PORTIONS OF THE TX PANHANDLE/SOUTH PLAINS INTO NWRN TX LATER THIS AFTERNOON. TORNADO POTENTIAL WILL ALSO INCREASE WITH EWD EXTENT AS WELL...AS THE LOW-LEVEL JET AXIS WILL BE ALIGNED ACROSS N TX INTO CNTRL OK. HOWEVER...TORNADO POTENTIAL COULD STILL ACCOMPANY ANY SUSTAINED DISCRETE SUPERCELL GIVEN STRONG DEEP-LAYER SHEAR AND A MOIST BOUNDARY LAYER WITH LOW LCLS...AND ESPECIALLY WITH ANY BOUNDARY INTERACTION. TRENDS ARE BEING MONITORED FOR A WW...WHICH WILL PROBABLY BE ISSUED BEFORE 19Z. ..ROGERS/DIAL.. 05/16/2015 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FWD...OUN...SJT...LUB...AMA...MAF... LAT...LON 31470082 32120139 34010239 35080208 35350077 35469963 34879874 32459899 31719970 31470082 NNNN