| Categorical Graphic |
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| Probabilistic Tornado Graphic |
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| Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point. |
| Probabilistic Damaging Wind Graphic |
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| Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point. |
| Probabilistic Large Hail Graphic |
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| Probability of hail 1" or larger within 25 miles of a point. Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point. |
SPC AC 192000 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0300 PM CDT THU MAY 19 2011 VALID 192000Z - 201200Z ...THERE IS A MDT RISK OF SVR TSTMS ACROSS CENTRAL KANSAS AND A PORTION OF NORTHWEST AND WESTERN OKLAHOMA... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM WEST TX TO SRN NEB... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE NORTHEAST FROM SERN NY AND ERN PA AND NJ TO DELMARVA... ...OK/KS... INTENSE SUPERCELL DEVELOPMENT ALONG THE DRYLINE IN WRN OK OVER THE PAST TWO HOURS...AND HIGHER CONFIDENCE IN SIGNIFICANT SEVERE STORMS ACROSS CENTRAL KS THIS AFTERNOON HAVE RESULTED IN AN INCREASE IN HAIL AND TORNADO PROBABILITIES ACROSS THESE AREAS...AND THE INTRODUCTION OF A MDT RISK OF SEVERE STORMS THIS AFTERNOON AND TONIGHT. SUPERCELLS IN OK WILL CONTINUE TO POSE A VERY LARGE HAIL THREAT AS WELL AS SOME TORNADO POTENTIAL AS THEY TRACK NNEWD ACROSS WRN PORTIONS OF THE STATE THROUGH THE AFTERNOON. MEANWHILE...A MORE VOLATILE ENVIRONMENT APPEARS TO BE DEVELOPING NEAR TRIPLE-POINT LOW INVOF WRN AND CNTRL KS. STORM INITIATION APPEARS IMMINENT ALONG THE WARM FRONT TO THE WEST OF ICT TO HLC. AIRMASS DESTABILIZATION CONTINUES ACROSS THIS AREA AND SHOULD FUEL INTENSE STORM UPDRAFTS. LOCALLY BACKED LOW LEVEL FLOW TOPPED BY CLASSIC DIFFLUENT EXIT REGION OF MID/UPPER JET WILL SUPPORT SUPERCELLS GIVEN EFFECTIVE DEEP-LAYER SHEAR OF 40-60KT. IN ADDITION TO VERY LARGE HAIL...EFFECTIVE SRH ON THE ORDER OF 200 M2/S2 ALONG THE WARM FRONT SHOULD ALSO SUPPORT THE POTENTIAL FOR A COUPLE TO A FEW STRONG TORNADOES. GIVEN THE SUPPORTIVE INGREDIENTS IN PLACE...BUT STILL SOME QUESTIONS ABOUT STORM EVOLUTION/COVERAGE...SUFFICIENT CONFIDENCE EXISTS FOR AN UPGRADE TO MDT RISK WITH THIS OUTLOOK. ..CARBIN.. 05/19/2011 .PREV DISCUSSION... /ISSUED 1122 AM CDT THU MAY 19 2011/ ...CENTRAL/SOUTHERN PLAINS... SATELLITE IMAGERY THE PAST 6 HOURS SHOWS THE UPPER WINDS HAVE STARTED TO BACK ACROSS THE SRN/CENTRAL HIGH PLAINS...IN RESPONSE TO ONE SHORTWAVE TROUGH LIFTING NWWD FROM THE CENTRAL PLAINS TOWARD THE NRN ROCKIES...AND AN IMPRESSIVE SHORTWAVE TROUGH MOVING ESEWD THROUGH SRN CA TOWARD AZ. THIS SHOULD RESULT IN THE DRYLINE TO NOT MIXING AS FAR EAST AS WED...PERHAPS ONLY TO NEAR A DDC-GAG-ABI LINE BY LATE AFTERNOON. WV IMAGERY SUGGESTS A WEAK WAVE IS MOVING INTO WRN NM AND PRIMARY LIFT WILL SPREAD TOWARD ERN CO/WRN KS LATE IN THE DAY...BUT THE DYNAMICAL FORCING SHOULD BE WEAK OVER MOST OF THE WARM SECTOR. MOST MODELS...INCLUDING THE HIGH RESOLUTION VERSIONS...ARE CONSISTENT IN STORMS DEVELOPING 21-00Z IN AREA OF STRONGER LOW LEVEL CONVERGENCE NEAR INTERSECTION OF DRYLINE AND WARM FRONT IN CENTRAL KS. THE APPROACHING WAVE MAY ALSO AID STORM DEVELOPMENT SWD ALONG DRYLINE INTO NWRN OK. MODERATE INSTABILITY AND DEEP LAYER SHEAR AT 50-60 KT WILL FAVOR SUPERCELLS. THIS COMBINATION OF SHEAR AND INSTABILITY SHOULD SUPPORT HAIL IN EXCESS OF 2 INCHES...WIND DAMAGE AND TORNADOES...ESPECIALLY CLOSER TO THE WARM FRONT IN KS. ...SWRN OK SWWD INTO SWRN TX... DRYLINE WILL RETREAT WWD DURING THE NIGHT AND MAY PROVIDE FOCUS FOR THUNDERSTORMS TO DEVELOP...AFTER 06Z...AS LARGE SCALE FORCING INCREASES FROM THE WEST. THE COMBINATION OF DEWPOINTS CLIMBING BACK INTO THE MID 60S...STEEP MID LEVEL LAPSE RATES AND MID LEVEL SPEED MAX AT 50 KT WILL PROVIDE SUFFICIENT SHEAR AND INSTABILITY FOR SUPERCELLS. GIVEN THE TIME OF NIGHT AND SLIGHTLY STABLE BOUNDARY LAYER...EXPECT SEVERE HAIL TO BE THE MAIN THREAT... THOUGH STRONG DOWNDRAFTS MAY ALSO RESULT IN WIND DAMAGE. ...MID ATLANTIC STATES INTO SOUTHERN NEW ENGLAND... THE UPPER LOW IS CURRENTLY LOCATED OVER FAR NRN WV AND IS FORECAST TO SHIFT EWD ACROSS NRN MD THROUGH THE DAY. AT MID MORNING...WV IMAGERY SHOWS AN IMPRESSIVE SHORTWAVE MOVING NEWD AROUND UPPER LOW FROM NRN VA TOWARD ERN PA/NJ. CONVECTION HAS RECENTLY DEVELOPED AHEAD OF THIS FEATURE IN ERN PA AND SHOULD MOVE/SPREAD NWD THROUGH THE DAY ACROSS ERN PA/NJ AND NY. ALTHOUGH INSTABILITY IS NOT PARTICULARLY STRONG...SOME WARMING HAS RESULTED IN MLCAPES TO AROUND 500 J/KG. THIS INSTABILITY COMBINED WITH DEEP LAYER SHEAR AROUND 30 KT AND MID LEVEL LAPSE RATES BETWEEN 6.5-7.0 C/KM FAVOR MULTICELL STORMS WITH HAIL AND STRONG GUSTY WINDS. ANOTHER IMPULSE WAS LOCATED NEAR THE KY/WV BORDER AND ALL MODELS ARE SUGGESTIVE OF CONVECTION DEVELOPING LATER THIS AFTERNOON IN THE DELMARVA AREA WITH THIS SYSTEM. STORMS THAT DEVELOP WILL BE WITHIN A SLOWLY DRYING BOUNDARY LAYER AND WHEN COMBINED WITH WLY WINDS ALOFT AND STEEPENING LOW LEVEL LAPSE RATES...STRONG AND POSSIBLY SEVERE WIND GUSTS ARE POSSIBLE. CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z