The SPC is forecasting ...severe thunderstorms expected over parts of the south-central plains this afternoon and tonight.... Please read the latest public statement about this event.
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SPC AC 140558 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1258 AM CDT THU APR 14 2011 VALID 141200Z - 151200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM SERN KS THROUGH ERN OK INTO WRN AR AND EXTREME NERN TX... ...THERE IS A SLGT RISK OF SVR TSTMS FROM A PORTION OF THE CNTRL AND SRN PLAINS INTO THE LOWER MS VALLEY REGION... ...SYNOPSIS... SPLIT FLOW UPPER PATTERN WILL PREVAIL THURSDAY WITH A POTENT SHORTWAVE TROUGH CURRENTLY OVER THE GREAT BASIN EMERGING FROM SRN BRANCH AND CONTINUING THROUGH THE CNTRL AND SRN PLAINS. A SURFACE CYCLONE WILL DEEPEN AND LIFT NEWD THROUGH KS WITHIN UPPER JET EXIT REGION. STATIONARY FRONT NOW EXTENDS FROM NRN MO SWWD THROUGH KS INTO NWRN OK. ERN KS PORTION OF FRONT MAY LIFT NWD INTO EXTREME SERN NEB AS SURFACE LOW DEEPENS OVER CNTRL KS. DRYLINE WILL SHARPEN AND EXTEND SWD FROM THE LOW THROUGH CNTRL OK AND N-CNTRL TX. PACIFIC FRONT WILL ADVANCE EWD AND EVENTUALLY MERGE WITH DRYLINE ACROSS ERN OK...THEN CONTINUE TOWARD THE LOWER MS VALLEY OVERNIGHT. ...KS...ERN OK THROUGH THE LOWER MS VALLEY AREA... RICH GULF MOISTURE RESIDES ACROSS SRN TX WITH LOW 60S DEWPOINTS AS FAR NORTH AS CNTRL TX. A SLY LOW LEVEL JET WILL PERSIST FROM CNTRL-NCNTRL TX AND SHIFT NWD THROUGH ERN OK AND KS IN RESPONSE TO DEEPENING SURFACE LOW. THIS WILL RESULT IN NWD ADVECTION OF RICHER MOISTURE WITH LOW 60S DEWPOINTS LIKELY ACROSS CNTRL-ERN OK AND NEAR 60 DEWPOINTS INTO SERN KS. EWD ADVECTING EML PLUME AND COLD TEMPERATURES ALOFT ACCOMPANYING THE UPPER TROUGH SHOULD YIELD 8-8.5 C/KM 700-500 MB LAPSE RATES ABOVE THE MOISTENING BOUNDARY LAYER. SOME STRATUS WILL LIKELY DEVELOP EARLY THURSDAY FROM PARTS OF N-CNTRL TX...OK AND KS IN ASSOCIATION WITH RETURN OF RICHER MOISTURE. HOWEVER...DIABATIC WARMING IS EXPECTED BY EARLY AFTERNOON AS LOW CLOUDS MIX OUT...RESULTING IN AXIS OF 2000-2500 J/KG MLCAPE FROM N-CNTRL TX...ERN HALF OF OK INTO SERN KS WITH MORE LIMITED INSTABILITY FARTHER NORTH. ELEVATED STORMS WILL LIKELY BE ONGOING OR DEVELOP EARLY WITHIN ZONE OF ISENTROPIC LIFT NORTH OF THE FRONT FROM NRN KS INTO NEB. THIS ACTIVITY COULD POSE A THREAT FOR MARGINALLY SEVERE HAIL. INITIAL SURFACE BASED STORMS ARE EXPECTED BY EARLY AFTERNOON WITHIN ZONE OF DEEP ASCENT ASSOCIATED WITH UPPER JET EXIT REGION INTERACTING WITH OCCLUDED FRONT/DRYLINE ACROSS CNTRL KS. VERTICAL SHEAR WILL SUPPORT SUPERCELLS WITH LARGE HAIL AND TORNADOES POSSIBLE. OTHER STORMS WILL LIKELY INITIATE ALONG THE DRYLINE FROM SRN KS...CNTRL-ECNTRL OK...AND POSSIBLY INTO N-CNTRL TX BY MID-LATE AFTERNOON. THESE STORMS WILL LIKELY BE DISCRETE SUPERCELLS CAPABLE OF PRODUCING VERY LARGE HAIL AND TORNADOES. GREATEST TORNADO THREAT IS EXPECTED IN MODERATE RISK AREA WHERE 0-1 KM HODOGRAPH SIZE WILL INCREASE TOWARD EVENING WHILE STORMS ARE STILL DISCRETE AND BEFORE THE BOUNDARY LAYER BEGINS TO DECOUPLE. ADDITIONAL STORMS WILL LIKELY DEVELOP AS THE FRONT OVERTAKES THE DRYLINE...AND THIS ACTIVITY WILL PROBABLY BEGIN TO GROW UPSCALE AS IT CONTINUES THROUGH ERN OK INTO THE LOWER MS VALLEY OVERNIGHT WHERE THE THREAT FOR DAMAGING WIND MAY ALSO INCREASE. ..DIAL/COHEN.. 04/14/2011 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z