Categorical Graphic
Probabilistic Graphic
Probability of severe weather within 25 miles of a point. Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.

   SPC AC 300721
   
   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0221 AM CDT MON MAY 30 2011
   
   VALID 011200Z - 021200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER THE NERN STATES...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF THE CNTRL AND
   NRN PLAINS INTO THE UPPER MS VALLEY...
   
   ...SYNOPSIS...
   
   NRN PERIPHERY OF SUBTROPICAL HIGH ANCHORED OVER THE SRN U.S. WILL
   REMAIN SUPPRESSED BY PROGRESSIVE UPPER TROUGH THAT WILL MOVE FROM
   THE GREAT LAKES INTO QUEBEC AND THE NERN STATES. FARTHER UPSTREAM
   ANOTHER UPPER LOW WILL MOVE FARTHER INTO THE WESTERN STATES. AT THE
   SURFACE A COLD FRONT WILL ACCOMPANY THE UPPER TROUGH THROUGH NERN
   U.S. WHILE TRAILING PORTION OF THIS BOUNDARY WILL RETURN NWD AS A
   WARM FRONT THROUGH THE CNTRL PLAINS.  
   
   ...NERN STATES THROUGH MID ATLANTIC...
   
   RICHER MOISTURE WITH MID-UPPER 60S DEWPOINTS WILL HAVE ADVECTED
   THROUGH THE PRE-FRONTAL WARM SECTOR BENEATH REMNANT EML. THIS WILL
   RESULT IN MODERATE INSTABILITY FROM THE NERN STATES INTO THE MID
   ATLANTIC REGION. WHILE VERTICAL SHEAR WILL REMAIN MODEST OVER MUCH
   OF THIS REGION EXCEPT FOR MAINE...DEEP LAYER WINDS WILL GRADUALLY
   STRENGTHEN AS THE UPPER TROUGH ADVANCES THROUGH THE GREAT LAKES AND
   SRN CANADA. STORMS WILL LIKELY DEVELOP AHEAD OF THE FRONT AS THE
   BOUNDARY LAYER WARMS. BOTH MULTICELL AND SUPERCELL STORM STRUCTURES
   WILL BE POSSIBLE WITH SUPERCELLS MORE LIKELY FARTHER NWD INTO NEW
   ENGLAND. DAMAGING WIND AND LARGE HAIL WILL BE THE PRIMARY THREATS.
   
   ...NEB...SD...IA AND SRN MN...
   
   THE ATMOSPHERE WILL BECOME QUITE UNSTABLE ALONG AND SOUTH OF WARM
   FRONT AS RICHER MOISTURE RETURNS NWD BENEATH STEEP LAPSE RATES. A
   WEAK UPPER RIDGE WILL BUILD IN WAKE OF UPPER TROUGH MOVING THROUGH
   THE GREAT LAKES WHICH IN CONJUNCTION WITH EWD EXPANDING EML SUGGEST
   THE MOIST WARM SECTOR COULD POTENTIALLY REMAIN CAPPED OR SURFACE
   BASED STORM COVERAGE MIGHT BE LIMITED. NEVERTHELESS A FEW STORMS
   WILL BE POSSIBLE NEAR THE WARM FRONT DURING PEAK AFTERNOON HEATING
   OVER A PORTION OF CNTRL NEB WHERE DEEPER VERTICAL SHEAR AND LOW
   LEVEL HODOGRAPHS WILL PROMOTE SUPERCELLS. A HIGHER CONFIDENCE EXISTS
   THAT ELEVATED STORMS WILL DEVELOP OVERNIGHT NORTH OF THE WARM FRONT
   WITHIN ZONE OF ISENTROPIC LIFT FROM ERN SD...NWRN IA INTO SRN MN
   WHERE THE THERMODYNAMIC ENVIRONMENT AND EFFECTIVE SHEAR WILL BE
   SUFFICIENT FOR HAILSTORMS. 
   
   ...WRN KS AND ERN CO THROUGH SRN HIGH PLAINS...
   
   DEEP MIXING ALONG WRN EDGE OF RICHER MOISTURE WILL LIKELY PROMOTE A
   FEW STORMS DEVELOPING FROM THE SRN THROUGH CNTRL HIGH PLAINS. DEEP
   LAYER SHEAR WILL DECREASE WITH SWD EXTENT INTO THE SRN PLAINS...BUT
   STEEP LAPSE RATES AND MODERATE INSTABILITY WILL SUPPORT A THREAT OF
   ISOLATED LARGE HAIL AND DOWNBURSTS.
   
   ...SERN STATES...
   
   WIDELY SCATTERED TO SCATTERED STORMS WILL BE POSSIBLE DURING THE
   AFTERNOON WITH GREATEST COVERAGE EXPECTED ALONG THE APPALACHIANS.
   WEAK VERTICAL SHEAR BENEATH UPPER RIDGE WILL PROMOTE MULTICELL
   STORMS...BUT STEEP LAPSE RATES AND MODERATE INSTABILITY WILL SUPPORT
   A THREAT OF ISOLATED DOWNBURSTS AND MARGINALLY SEVERE HAIL THROUGH
   EARLY EVENING.
   
   ..DIAL.. 05/30/2011
   
   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z