SPC AC 251630 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1130 AM CDT WED MAR 25 2015 VALID 251630Z - 261200Z ...THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF CNTRL AND NRN OK...SW MO...AND NW AR... ...THERE IS AN ENH RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM SW OK ENE INTO PARTS OF SRN MO AND NRN AR... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE ENH RISK AREA FROM PARTS OF N TX NEWD INTO THE LWR OH VLY... ...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING THE ABOVE AREAS FROM S CNTRL TX NEWD INTO THE MID-OH VLY... ...SUMMARY... NUMEROUS SEVERE THUNDERSTORMS...CAPABLE OF VERY LARGE HAIL...DAMAGING WINDS AND PERHAPS A TORNADO ARE EXPECTED OVER PARTS OF THE SOUTHERN PLAINS AND OZARKS LATE THIS AFTERNOON AND EVENING...PERHAPS CONTINUING INTO PARTS OF THE LOWER OHIO VALLEY LATE TONIGHT. ...SYNOPSIS... WITHIN A BROAD UPPER-LEVEL TROUGH OVER THE CENTRAL CONUS...A SHORTWAVE IMPULSE OVER WY/CO WILL MOVE EAST ACROSS KS/OK THIS AFTERNOON AND INTO THE OZARKS/MID-MS VALLEY BY 12Z THURSDAY. TWO WEAKER UPPER-LEVEL IMPULSES OVER WRN NM AND W TX WILL ALSO MOVE ACROSS THE SRN PLAINS THIS AFTN/EVENING. A SURFACE COLD FRONT NOW MOVING SWD THROUGH THE CENTRAL PLAINS WILL SURGE SWD ACROSS THE SRN PLAINS TONIGHT...WHILE A FRONTAL BOUNDARY THAT MOVED THROUGH THE SRN PLAINS/OZARKS TUESDAY WILL LIFT NORTH TODAY. SLY LOW-LEVEL FLOW ACROSS THE SRN PLAINS TODAY WILL RESULT IN UPPER 50S/NEAR 60 DEW POINTS AS FAR NORTH AS CENTRAL/ERN OK...AR...EWD TO WRN PORTIONS OF TN/KY. ...SRN PLNS/OZARKS TO LWR OH VLY TODAY/TNGT... BROAD SURFACE LOW OVER THE TX PANHANDLE WILL BECOME BETTER FOCUSED BY MID/LATE AFTN ACROSS SWRN/W-CENTRAL OK...WITH A NEARLY STATIONARY FRONTAL BOUNDARY EXTENDING EWD FROM THE LOW ACROSS SRN PORTIONS OF MO/IL. A DRY LINE WILL EXTEND SWD FROM THE SURFACE LOW ACROSS WRN PORTIONS OF N TX. LATER THIS EVENING...THE STRONGER COLD FRONT WILL OVERTAKE THIS FRONTAL BOUNDARY AND BECOME THE PRIMARY SURFACE FEATURE. STG/ISOLD SVR TSTMS WITH A THREAT FOR LARGE HAIL WILL CONTINUE TO DEVELOP NORTH OF THE SFC BOUNDARY OVER S-CENTRAL/SERN KS AIDED BY LOW-LEVEL WAA. REF MCD 138 FOR THE LATEST SHORT-TERM DETAILS IN THIS AREA. BY MID-AFTN...STRENGTHENING LOWER-MID TROPOSPHERIC WIND FIELDS...STEEP MID-LEVEL LAPSE RATES AND INCREASING BOUNDARY LAYER MOISTURE WILL RESULT IN A VERY FAVORABLE ENVIRONMENT FOR RAPID SURFACE-BASED SVR TSTM DEVELOPMENT FROM SRN MO/NRN AR WWD TO NRN/CENTRAL OK. STRONG DIURNAL HEATING AND MODEST LARGE-SCALE FORCING FOR ASCENT WILL COMBINE TO REDUCE CINH ACROSS NRN OK EWD TO SRN MO/AR. INITIALLY DISCRETE SUPERCELL STORMS WILL POSE A LARGE HAIL/DAMAGING WIND RISK...WITH A TORNADO POSSIBLE. VERY LARGE HAIL...IN EXCESS OF TWO INCHES IN DIAMETER...IS POSSIBLE GIVEN THE STEEP MID-LEVEL LAPSE RATES IN PLACE. ORIENTATION OF SHEAR VECTORS RELATIVE TO THE FRONTAL BOUNDARY SUGGESTS EVENTUAL EVOLUTION INTO SHORT BOWING SEGMENTS IS LIKELY WITH DAMAGING WINDS THE DOMINANT RISK EWD THROUGH THE OH RIVER VALLEY TONIGHT. ACROSS CENTRAL/SWRN OK...LAST SEVERAL RUNS OF THE NCEP HRRR ARE CONSISTENT IN DEVELOPING SUPERCELLS NEAR THE SURFACE LOW AND ALONG THE DRYLINE BY MID TO LATE AFTN. THESE STORMS WOULD POSE A RISK FOR VERY LARGE HAIL AND DAMAGING GUSTS FOR A FEW HOURS BEFORE BEING UNDERCUT BY THE ADVANCING COLD FRONT. ALTHOUGH A TORNADO OR TWO WILL BE POSSIBLE...LARGE SFC TEMP-DEW POINT SPREADS AND RESULTANT HIGH LCL HEIGHTS WILL TEND TO MITIGATE POTENTIAL FOR PERSISTENT LOW-LEVEL ROTATION. WITH TIME...STORMS SHOULD DEVELOP A MORE LINEAR STRUCTURE ALONG THE COLD FRONT ACROSS ERN OK. FARTHER SOUTH...MORE ISOLD SVR TSTM DEVELOPMENT IS PSBL SWD ALONG THE DRYLINE INTO PORTIONS OF N TX THROUGH EARLY EVENING WHERE A MODERATELY UNSTABLE AIR MASS WILL EXIST IN THE PRESENCE OF 40-45 KTS OF DEEP-LAYER SHEAR. LARGE HAIL AND DAMAGING GUSTS WILL BE THE PRIMARY THREATS. LATER TONIGHT...TSTM COVERAGE SHOULD INCREASE ALONG THE COLD FRONT INTO N TX. ...CAROLINAS... TSTMS WILL BE POSSIBLE ALONG A CONFLUENCE ZONE AND WITHIN A MOIST /PW AOA ONE INCH/ AIR MASS TONIGHT ACROSS PORTIONS OF THE CAROLINAS. WHILE A WEAKLY ROTATING STORM IS NOT OUT OF THE QUESTION...FORECAST SOUNDINGS SUGGEST THE OVERALL SVR RISK IS LOW AND WILL NOT INTRODUCE SVR PROBS WITH THIS OUTLOOK. ..BUNTING/MEAD/COHEN.. 03/25/2015 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z