The SPC is forecasting ...severe thunderstorms expected over parts of the cntrl plains...srn plains and ozarks this afternoon and evening.... Please read the latest public statement about this event.
| Categorical Graphic |
|---|
|
| Probabilistic Tornado Graphic |
 |
 |
| Probabilistic Damaging Wind Graphic |
 |
 |
| Probabilistic Large Hail Graphic |
 |
 |
SPC AC 091615 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1115 AM CDT THU APR 09 2009 VALID 091630Z - 101200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER PARTS OF EASTERN OK...SOUTHEAST KS...SOUTHWEST MO AND WESTERN AR... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE SOUTHERN PLAINS INTO THE MID MS VALLEY... PREVIOUS FORECAST LOOKS ON TRACK FOR A FOCUSED BUT POTENTIALLY SIGNIFICANT SEVERE WEATHER EVENT LATER THIS AFTERNOON/EVENING IN ADVANCE OF THE STRONG UPPER TROUGH CURRENTLY MOVING EWD ACROSS SRN HIGH PLAINS. AN ELONGATED SURFACE LOW ALONG KS/OK BORDER WITH PRIMARY CENTER SWRN KS EXPECTED TO CONSOLIDATE AND MOVE EWD TO BE LOCATED S OF ICT BY LATER THIS AFTERNOON. ...SOUTHEASTERN KS/NORTHEASTERN OK THIS AFTERNOON... DRY LINE CURRENTLY SHARPENING UP WRN OK WILL BE PRIMARY FOCUS FOR SEVERE THUNDERSTORM INITIATION AFTER 21Z. RAPID MOISTENING OF THE BOUNDARY LAYER IS OCCURRING THIS MORNING AS STRONG SOUTHERLY LOW LEVEL JET TRANSPORTS GULF AIRMASS NORTHWARD INTO OK/AR. BY MID AFTERNOON...SURFACE DEWPOINTS IN THE MID TO UPPER 50S ARE EXPECTED OVER MOST OF EASTERN OK EAST OF THE DRYLINE...WITH NEAR 50F DEWPOINTS WRAPPING WESTWARD ALONG THE KS/OK BORDER NEAR THE SURFACE LOW. THE CAPPING INVERSION WILL SUPPRESS SURFACE-BASED CONVECTION OVER THIS REGION UNTIL EARLY THIS AFTERNOON. HOWEVER...IT APPEARS LIKELY THAT STRONG FORCING AND COOLING ALOFT WILL YIELD A NARROW ZONE OF WEAKENING CAP ALONG THE OK/KS BORDER BY 19-21Z. ISOLATED THUNDERSTORMS WILL LIKELY DEVELOP IN THIS ZONE AND TRACK NORTHEASTWARD INTO SOUTHEASTERN KS. FORECAST SOUNDINGS IN THIS REGION SUGGEST THE RISK OF RELATIVELY LOW-TOPPED SUPERCELLS CAPABLE OF HAIL AND ISOLATED TORNADOES. ...EASTERN OK/SOUTHWEST MO/WESTERN AR... ONLY ADJUSTMENT IN THIS AREA WAS TO SHIFT THE INITIATION ZONE A LITTLE FURTHER W BASED ON SUGGESTIONS BY HIGH RES MODELS AND RUC THAT THE STRONG HEATING COULD ERODE CAP SUFFICIENTLY ALONG DRY LINE TO REMOVE CINH PRIOR TO DRY LINE MIXING TO THE E OF A TUL/MLC LINE. UPON DEVELOPMENT...THESE STORMS WILL MOVE INTO SOUTHWEST MO AND WESTERN AR DURING THE EVENING. STEEP MID LEVEL LAPSE RATES AND COOL TEMPERATURES ALOFT...COUPLED WITH SUFFICIENT EFFECTIVE SHEAR FOR SUPERCELLS WILL PROMOTE THE RISK OF VERY LARGE HAIL IN STRONGER CELLS. FORECAST SOUNDINGS ALSO INDICATE SUBSTANTIAL VEERING AND INCREASING LOW LEVEL WINDS WITH HEIGHT...POSING A RISK OF SIGNIFICANT TORNADOES OVER THE MODERATE RISK AREA THROUGH EARLY EVENING. SURFACE DEWPOINT VALUES ARE ONLY FORECAST TO REACH THE LOWER 60S AT BEST ACROSS THE MDT AREA...BUT RAPIDLY COOLING TEMPERATURES ALOFT AND STRENGTH OF VERTICAL SHEAR EXPECTED TO RESULT IN MLCAPES TO 2000 J/KG AND WIND PROFILES MORE THAN SUFFICIENT TO SUPPORT DEVELOPMENT OF TORNADIC SUPERCELLS. OVERNIGHT...THUNDERSTORMS WILL LIKELY INCREASE IN COVERAGE AS THEY SPREAD EASTWARD ACROSS AR AND SOUTHERN MO INTO WESTERN KY/TN. THE SEVERE THREAT WILL LIKELY BECOME LESS ORGANIZED...BUT STRONGER CELLS WILL REMAIN CAPABLE OF HAIL AND DAMAGING WINDS MUCH OF THE NIGHT. ..HALES/SMITH.. 04/09/2009 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z