Jun 4, 2011 0600 UTC Day 1 Convective Outlook
Updated: Sat Jun 4 05:00:05 UTC 2011
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20110604 1200 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20110604 1200 UTC Day 1 Tornado Probabilities 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
20110604 1200 UTC Day 1 Damaging Wind Probabilities 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
20110604 1200 UTC Day 1 Large Hail Probabilities 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 040456
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1156 PM CDT FRI JUN 03 2011
   
   VALID 041200Z - 051200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH VALLEY...SRN GREAT
   LAKES WWD INTO THE MID MO RIVER VALLEY...
   
   ...SYNOPSIS...
   UPPER TROUGH...CURRENTLY MOVING THROUGH THE NRN PLAINS...WILL SHIFT
   EWD THROUGH THE GREAT LAKES ON SATURDAY AND FLATTEN THE NRN EXTENT
   OF THE UPPER RIDGE ACROSS THE GREAT LAKES/OH VALLEY. WEAK COLD WILL
   ACCOMPANY THE UPPER TROUGH AND IS FORECAST TO EXTEND FROM SERN LOWER
   MI SWWD NEAR THE MO/IA BORDER AND INTO NRN KS/ERN CO BY LATE
   AFTERNOON. ELSEWHERE...THE LARGE UPPER RIDGE WILL REMAIN ANCHORED
   OVER THE SOUTHERN HALF OF THE COUNTRY...EXCEPT IN THE FAR WEST WHERE
   A CLOSED LOW WILL APPROACH THE CA COAST.
   
   ...OH VALLEY/GREAT LAKES/MID-MO VALLEY...
   MODELS ARE SUGGESTIVE OF SCATTERED THUNDERSTORMS DEVELOPING AHEAD OF
   THE FRONT DURING THE AFTERNOON AS HEIGHTS GRADUALLY LOWER AND
   CONVERGENCE INCREASES AHEAD OF SEWD MOVING COLD FRONT. HEATING OF
   THE RICH BOUNDARY LAYER MOISTURE...DEWPOINTS IN THE LOWER TO MID
   70S...WILL RESULT IN MLCAPES TO EXCEED 3000 J/KG FROM SRN LOWER
   MI/OH WWD INTO SRN IA/NRN MO. MID LEVEL WINDS ARE FORECAST TO
   GRADUALLY INCREASING INTO THE 25-40 KT RANGE DURING THE DAY...BUT
   THE DEEP LAYER SHEAR IS ONLY FORECAST TO RANGE FROM 25-35 KT DUE TO
   MOSTLY UNIDIRECTIONAL WLY WINDS ABOVE THE SURFACE. THE COMBINATION
   OF STRONG INSTABILITY AND UNIDIRECTIONAL WLY FLOW SHOULD SUPPORT ONE
   OR TWO LINEAR MCS/S MOVING ESEWD WITHIN THE SLIGHT RISK AREA. WHILE
   THE MAIN THREAT WILL BE WIND DAMAGE... SEVERE HAIL IS POSSIBLE WITH
   STORMS BEFORE OUTFLOWS MERGE. THESE STORMS ARE EXPECTED TO MOSTLY
   DIMINISH IN INTENSITY BETWEEN 03-06Z DUE TO WEAKENING INSTABILITY.
   HOWEVER...00Z NAM/GFS SUGGEST ELEVATED CONVECTION MAY DEVELOP
   OVERNIGHT IN IOWA WITHIN ZONE OF INCREASING LOW LEVEL JET/WARM
   ADVECTION. HAIL WOULD BE POSSIBLE WITH THIS ACTIVITY.
   
   ...CENTRAL HIGH PLAINS...
   UPSLOPE FLOW WILL ADVECT A MORE MOIST BOUNDARY LAYER WWD INTO THE
   FOOTHILLS WITH AT LEAST MID AND UPPER 40S RESULTING IN MODERATE
   INSTABILITY. SURFACE HEATING AND TOPOGRAPHICAL FORCED LIFTING MAY BE
   SUFFICIENT FOR HIGHER BASED STORMS TO DEVELOP BY LATE AFTERNOON.
   STRONGLY VEERING WIND PROFILES WOULD SUGGEST THAT A SUPERCELL OR TWO
   WOULD BE POSSIBLE WITH HAIL THE MAIN THREAT. HOWEVER...BUILDING 500
   MB HEIGHTS SUGGEST STORMS SHOULD BE VERY ISOLATED...SO ONLY LOW
   SEVERE WEATHER PROBABILITIES ARE FORECAST.
   
   ...SRN HIGH PLAINS...
   STORMS ARE ONCE AGAIN EXPECTED TO DEVELOP DURING THE AFTERNOON
   HOURS. WHILE SHEAR AND INSTABILITY WILL NOT BE PARTICULARLY
   STRONG...LARGE TEMPERATURE/DEWPOINT SPREADS ON THE ERN END OF THE
   CONVECTION IS LIKELY TO RESULT IN A FEW STRONG WIND GUSTS...
   ESPECIALLY BY EARLY EVENING WHEN THE STORMS ARE WEAKENING.
   
   ...GULF COAST STATES...
   A MODERATELY TO STRONGLY UNSTABLE AIR MASS WILL LIKELY BE IN PLACE
   AGAIN ACROSS THE REGION ON SATURDAY. AS TEMPERATURES WARM WELL INTO
   THE 90S...A FEW THUNDERSTORM ARE EXPECTED TO DEVELOP FROM THE FL
   PANHANDLE WWD INTO FAR ERN TX. THE COMBINATION OF STEEP LOW-LEVEL
   LAPSE RATES...STRONG INSTABILITY AND WEAK SHEAR WILL BE FAVORABLE
   FOR ISOLATED MICROBURSTS AND SOME SEVERE HAIL...MAINLY BETWEEN
   20-02Z.
   
   ..IMY/COHEN.. 06/04/2011
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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