Categorical Graphic
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 030521
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1221 AM CDT FRI JUN 03 2011
   
   VALID 031200Z - 041200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MS 
   VALLEY AND GREAT LAKES REGION...
   
   ...SYNOPSIS...
   UPPER TROUGH IN THE NRN ROCKIES WILL MOVE NEWD INTO SOUTH CENTRAL
   CANADA...WITH THE SRN END OF THE TROUGH MOVING EWD THROUGH ND AND
   INTO MN BY THE END OF THE PERIOD. A WEAK COLD FRONT WILL PUSH SEWD
   AHEAD OF THIS TROUGH AND IS FORECAST TO EXTEND FROM NEAR THE MN/WI
   BORDER INTO NWRN KS/ERN CO BY LATE AFTERNOON. AHEAD OF THE UPPER
   TROUGH...HIGH PRESSURE RIDGE WILL BUILD NEWD FROM THE MID MS VALLEY
   INTO THE GREAT LAKES...AS AN UPPER TROUGH DIGS SEWD FROM NEW ENGLAND
   INTO THE ATLANTIC.
   
   ...UPPER MS VALLEY AND WRN GREAT LAKES...
   STORMS CURRENTLY LOCATED OVER THE DAKOTAS ARE EXPECTED TO
   DEVELOP/MOVE THROUGH MN AND INTO ONTARIO BY MID MORNING AS
   LOW LEVEL JET VEERS AND MASS CONVERGENCE MOVES NORTH OF THE BORDER.
   THIS SHOULD ALLOW SKIES TO BECOME PARTY CLOUDY AHEAD OF THE
   FRONT...AND WARMING TEMPERATURES WILL RESULT IN A STRONGLY UNSTABLE
   AIR MASS BY AFTERNOON. THE COMBINATION OF LARGE SCALE LIFTING AND A
   WEAK CAPPING INVERSION SHOULD RESULT IN THUNDERSTORMS DEVELOPING
   ACROSS CENTRAL/ERN MN AROUND MID AFTERNOON. ONCE STORMS
   DEVELOP...40-50 KT DEEP LAYER SHEAR COMBINED WITH STEEP MID-LEVEL
   LAPSE RATES/STRONG INSTABILITY SHOULD GENERATE SUPERCELLS WITH LARGE
   HAIL THE PRIMARY THREAT. A FEW TORNADOES ARE ALSO POSSIBLE
   ...ESPECIALLY ACROSS NRN WI WHERE FORECAST SOUNDINGS SHOW LOW LCLS
   AND 1KM SHEAR AROUND 20 KT. HOWEVER...NEARBY UPPER RIDGING PRECLUDES
   A TORNADO PROBABILITY HIGHER THAN 5 PERCENT. BY SUNSET...MOSTLY
   UNIDIRECTIONAL WSWLY WINDS ABOVE THE BOUNDARY LAYER MAY RESULT IN A
   TRANSITION FROM DISCRETE STORMS TO A LINEAR MCS...WITH A  HIGHER
   THREAT FOR WIND DAMAGE.
   
   ...CENTRAL PLAINS...
   AN AXIS OF WEAK TO MODERATE INSTABILITY SHOULD BE IN PLACE AHEAD OF
   A SEWD MOVING COLD FRONT. HOWEVER...WARM MID LEVEL TEMPERATURES
   SHOULD INHIBIT CONVECTION UNTIL LATE IN THE DAY WHEN STRONG HEATING
   WOULD AID PARCELS REACHING LCL/LFC. THESE STORMS SHOULD BE VERY
   ISOLATED...THOUGH THE DEEPLY MIXED BOUNDARY LAYER WOULD SUPPORT
   STRONG WIND GUSTS. AFTER DARK...STRONG FORCING IS FORECAST WITH EXIT
   REGION OF UPPER JET AND AIDS IN STRENGTHENING LOW LEVEL JET.
   THUNDERSTORMS ARE FORECAST TO DEVELOP AND/OR SPREAD NORTH OF THE
   FRONT AND SHIFT FROM WRN KS INTO NEB/IA OVERNIGHT. HAIL WOULD BE
   POSSIBLE WITH THESE ELEVATED STORMS. FORECAST SOUNDINGS SHOW THAT
   THE INSTABILITY WOULD BE MARGINAL FOR A MORE WIDESPREAD HAIL THREAT
   AND SLIGHT RISK ISSUANCE.
   
   ...ERN GULF COAST STATES/SOUTH CAROLINA...
   MODERATE TO STRONG INSTABILITY SHOULD ONCE DEVELOP WITHIN A
   A HOT AND MOIST AIR MASS ACROSS THE REGION FRIDAY AFTERNOON.
   ALTHOUGH LARGE SCALE FORCING WILL BE WEAK...MODELS ARE CONSISTENT IN
   DEVELOPING SCATTERED THUNDERSTORMS DUE TO WEAK CAPPING. STORMS THAT
   DO DEVELOP WILL BE IN AN ENVIRONMENT WITH STEEP LOW-LEVEL LAPSE
   RATES AND MID LEVEL NLY WINDS AT 20 KT. THIS SHOULD BE SUFFICIENT
   FOR MULTICELLS WITH A MARGINAL HAIL AND WIND DAMAGE THREAT. IF
   STORMS CAN ORGANIZE A COLD POOL WITH THE SWD MOVING STORMS
   ...PORTIONS OF AREA COULD BE UPGRADED TO A SLIGHT RISK IN LATER DAY
   1 OUTLOOKS.
   
   ..IMY/COHEN.. 06/03/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z