Nov 8, 2011 1300 UTC Day 1 Convective Outlook | |
Updated: Tue Nov 8 12:49:08 UTC 2011 | |
Probabilistic to Categorical Outlook Conversion Table |
Categorical Graphic |
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Probabilistic Tornado Graphic |
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 |
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 |
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 081245 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0645 AM CST TUE NOV 08 2011 VALID 081300Z - 091200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE SOUTHERN PLAINS AND THE MID MS VALLEY... A STRONG AND PROGRESSIVE UPPER TROUGH CURRENTLY OVER NM WILL MOVE EASTWARD ACROSS THE SOUTHERN PLAINS AND INTO THE MID MS VALLEY BY WED MORNING. AS THIS OCCURS...A SURFACE LOW WILL TRACK FROM OK INTO MO/IL WITH A TRAILING COLD FRONT SWEEPING ACROSS TX/AR. SCATTERED STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE ACROSS THE WARM SECTOR OF THE LOW FROM OK/TX INTO MUCH OF THE MID AND LOWER MS VALLEY DURING THIS FORECAST PERIOD. ...OK/TX/LA... A BROKEN LINE OF CONVECTION CURRENTLY EXTENDS FROM SOUTHERN OK INTO CENTRAL TX. THESE STORMS ARE AHEAD OF THE MAIN COLD FRONT...AND SHOULD PROGRESS EASTWARD THROUGH THE DAY INTO EASTERN OK/EAST TX. POCKETS OF HEATING AHEAD OF THE ACTIVITY WILL LIKELY HELP DESTABILIZE THE AIR MASS AND INTENSIFY THE STORMS BY EARLY/MID AFTERNOON WITH AN INCREASING RISK OF LOCALLY SEVERE STORMS. GUSTY/DAMAGING WINDS APPEAR TO BE THE MAIN THREAT ACROSS THIS REGION. THE LOW LEVEL JET WILL WEAKEN SIGNIFICANTLY THROUGH THE LATE AFTERNOON AND EVENING AS THE UPPER SYSTEM DEPARTS TO THE NORTHEAST...HELPING TO DIMINISH THE SEVERE THREAT AFTER MIDNIGHT. ...AR/MO/IL... FARTHER NORTH...MODEL SOLUTIONS INDICATE THE MAIN SURFACE LOW WILL BE SLOWLY DEEPENING THROUGH THE EVENING/NIGHT AS IT TRACKS NORTHEASTWARD TOWARD THE STL AREA. STRENGTHENING LOW LEVEL WIND FIELDS AND VERTICAL SHEAR WILL POSE A CONDITIONAL RISK OF SEVERE STORMS AND EVEN ISOLATED TORNADOES ALONG A CORRIDOR FROM AR INTO SOUTHEAST MO AND SOUTHWEST IL. THIS THREAT WILL BE DEPENDENT ON THE EVOLUTION OF ONGOING PRECIPITATION AND WHETHER A MOIST/UNSTABLE AIR MASS CAN RETURN NORTHWARD. CURRENT MODEL SOLUTIONS PROVIDE SUFFICIENT EVIDENCE THAT THIS COULD OCCUR TO MAINTAIN THE SLIGHT RISK IN THESE AREAS. ..HART/COHEN.. 11/08/2011 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z