ZCZC SPCSWOMCD ALL ACUS11 KWNS 232325 SPC MCD 232325 TXZ000-OKZ000-240100- MESOSCALE DISCUSSION 0255 NWS STORM PREDICTION CENTER NORMAN OK 0625 PM CDT WED MAR 23 2016 AREAS AFFECTED...PORTIONS OF NORTHERN IN CENTRAL TX CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 232325Z - 240100Z PROBABILITY OF WATCH ISSUANCE...80 PERCENT SUMMARY...A SEVERE THUNDERSTORM WATCH IS LIKELY ACROSS PARTS OF NORTH TX THIS EVENING. LARGE HAIL AND DAMAGING WINDS WILL BE THE MAIN CONCERN. THE SOUTHWARD EXTENT OF THE SEVERE THREAT REMAINS UNCERTAIN...BUT COULD EXTEND AS FAR SOUTH AS CENTRAL TX INTO THE OVERNIGHT HOURS. DISCUSSION...THE SEVERE THREAT IS INCREASING ACROSS NORTH TX THIS EVENING...THOUGH THE SOUTHWARD EXTENT OF THIS SEVERE THREAT STILL REMAINS UNCERTAIN. A TONGUE OF GREATER INSTABILITY CURRENTLY LIES ACROSS THE METROPLEX VICINITY WITH MLCAPE VALUES NEAR 1500-2000 J/KG AHEAD OF THE SURFACE DRYLINE. LOW LEVEL CONFLUENCE ALONG THE DRYLINE COUPLED WITH INCREASING DEEP LAYER FORCING FOR ASCENT AS THE MAIN SHORTWAVE IMPULSE EJECTS INTO THE SOUTHERN PLAINS WILL SUPPORT FURTHER THUNDERSTORM DEVELOPMENT SOUTH OF THE RED RIVER. STEEP MIDLEVEL LAPSE RATES AND EFFECTIVE SHEAR GREATER THAN 45 KT WILL SUPPORT ROTATING UPDRAFTS AND LARGE HAIL WILL BE THE MAIN CONCERN AS INITIAL STORM MODE SHOULD BE SEMI-DISCRETE SUPERCELLS. WITH EASTWARD EXTENT...LOW LEVEL SHEAR WILL BECOME PARALLEL TO THE BOUNDARY. THIS MAY RESULT IN A TREND TOWARD LINEAR/BOWING SEGMENTS WITH DAMAGING WINDS POSSIBLE IN ADDITION TO LARGE HAIL. 0-1KM SRH WILL INCREASE TONIGHT AS THE LOW LEVEL JET STRENGTHENS AND A TORNADO OR TWO CAN NOT BE RULED OUT...BUT THE PRIMARY THREAT IS EXPECTED TO BE LARGE HAIL AND DAMAGING WINDS. FURTHER SOUTH INTO CENTRAL TX...UNCERTAINTY INCREASES WITH REGARDS TO SEVERE POTENTIAL. HI-RES GUIDANCE SUGGESTS STORMS WILL CONTINUE TO DEVELOP SOUTHWESTWARD ALONG/AHEAD OF THE DRYLINE. MODERATE INSTABILITY IS IN PLACE ACROSS THIS REGION WITH THE AXIS OF HIGHER MLCAPE VALUES SPREADING SOUTH/SOUTHWEST FROM THE METROPLEX TOWARD AUS AND VICINITY. ADDITIONALLY...AGITATED CU NEAR/JUST BEHIND THE DRYLINE WAS NOTED IN VIS SAT FROM NEAR DYS TO SJT. HOWEVER...FORCING FOR ASCENT AND LOW LEVEL FLOW IS WEAKER/LESS FAVORABLE ACROSS THIS REGION. HIGHER QUALITY MOISTURE IS ALSO LACKING GIVEN VEERED LOW LEVEL FLOW ACROSS THE SOUTHWESTERN PORTIONS OF THE MCD AREA. SHOULD STORMS DEVELOP THIS FAR SOUTH...LARGE HAIL WILL BE THE PRIMARY THREAT. ..LEITMAN/HART.. 03/23/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...SHV...FWD...OUN...EWX...SJT... LAT...LON 32549551 31969592 31049670 30269771 30099871 30169939 30439972 30859962 31549902 32439834 33439744 33749686 33819658 33799644 33879611 33819575 33709550 33449534 33149524 32549551 NNNN