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 251730
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1230 PM CDT FRI MAY 25 2012
   
   VALID 261200Z - 271200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS OVER CNTRL AND SRN MN...NRN
   IA...WRN WI...FAR ERN SD...
   
   ...SYNOPSIS...
   AN EXPANSIVE UPPER LOW WILL BE CENTERED OVER THE GREAT BASIN SAT
   MORNING...AND WILL EJECT NEWD ACROSS THE ROCKIES THROUGH THE PERIOD.
   IN ADVANCE OF THIS TROUGH...A BROAD AREA OF SWLY FLOW WILL EXIST
   OVER THE PLAINS...WITH AN UPPER RIDGE CENTERED OVER THE MIDDLE AND
   LOWER MS VALLEY.
   
   AT THE SURFACE...A WARM FRONT WILL LIFT NWD OUT OF NEB AND IA INTO
   SD...MN AND WI BY AFTERNOON. THE ERN PORTION OF THIS BOUNDARY WILL
   BE WEAK BUT WILL EXIST OVER NRN IND...OH AND PA. DEWPOINTS IN THE
   MID TO UPPER 60S F WILL EXIST FROM THE CNTRL PLAINS INTO THE OH
   VALLEY...RESULTING IN AMPLE INSTABILITY FOR THUNDERSTORMS.
   
   TO THE W AND LATER IN THE DAY...LOW PRESSURE WILL DEEPEN OVER SERN
   WY AND NERN CO AHEAD OF THE ADVANCING UPPER TROUGH. STRONG FORCING
   WILL DEVELOP IN THIS REGION...BUT INSTABILITY WILL BE WEAK.
   
   ...NRN PLAINS/UPPER MS VALLEY...
   A FAIRLY COMPLEX SCENARIO WILL UNFOLD ON SATURDAY. MODELS INDICATE
   THAT MULTIPLE EPISODES OF STORMS WILL BE POSSIBLE...BUT THERE IS
   DISAGREEMENT WITH EXACTLY WHERE THESE STORMS WILL FOCUS. IN A
   GENERAL SENSE...AREAS OF STORMS SHOULD EXIST NEAR THE WARM FRONT
   EARLY ON SAT...AND PERSIST AS THE FRONT LIFTS N. INSTABILITY AND
   SHEAR WILL STRONGLY FAVOR SUPERCELLS CAPABLE OF VERY LARGE
   HAIL...AND THE DEGREE OF INSTABILITY AND LARGE LOW LEVEL HODOGRAPHS
   WOULD ALSO FAVOR TORNADOES. THE MAIN QUESTION IS STORM COVERAGE IN
   THE WAKE OF THE EARLY ACTIVITY. THE SYNOPTIC PATTERN ALOFT IS
   RELATIVELY NEUTRAL...SO THIS EVENT WILL ALMOST ENTIRELY BE DRIVEN BY
   WARM ADVECTION. MODELS DO INDICATE A PLUME OF STRONGER HEATING AND
   LOW LEVEL LAPSE RATES FROM ERN NEB AND PERHAPS INTO WRN IA...WHICH
   COULD HELP BREAK THE CAP. AFTERNOON SOUNDINGS S OF THE WARM FRONT
   OVER IA APPEAR CAPPED...BUT CONDITIONALLY FAVORABLE FOR SIGNIFICANT
   SEVERE WEATHER. THUS...WILL INTRODUCE A BROAD SLIGHT RISK
   AREA...WITH LATER OUTLOOKS PROVIDING GREATER PRECISION.
   
   ...NERN WY...
   FORCING FOR ASCENT WILL INCREASE MARKEDLY AS THE SURFACE LOW DEEPENS
   AND SHEAR PROFILES WILL BE QUITE STRONG AND VEERING WITH HEIGHT.
   HOWEVER...INDICATIONS ARE THAT MOISTURE AND INSTABILITY WILL BE
   LIMITED IN GENERAL WITH ONLY A NARROW AXIS OF UPPER 40S TO PERHAPS
   LOWER 50S F DEWPOINTS EXTENDING WWD ALONG THE NEB/SD BORDER INTO FAR
   ERN WY. S OF THIS NARROW CORRIDOR...DEEP MIXING WILL OCCUR WITH
   INVERTED-V TYPE SOUNDINGS AND STRONG SHEAR. GIVEN THE STRENGTH OF
   THE FORCING AND ADVANCING COLD FRONT DURING THE EVENING...THERE WILL
   BE A THREAT OF ISOLATED SEVERE WIND...AND PERHAPS MARGINAL HAIL
   DEPENDING ON HOW MUCH INSTABILITY EXISTS.
   
   ...OH...NRN WV...PA...
   STRONG HEATING WILL OCCUR ACROSS THIS AREA...RESULTING IN AROUND
   1500 J/KG MUCAPE AS DEWPOINTS REMAIN IN THE MID 60S F. WINDS ALOFT
   WILL BE WEAK...AS WILL FORCING. HOWEVER...WITH FULL HEATING...AMPLE
   MOISTURE...AND AT LEAST WEAK LOW LEVEL CONVERGENCE...ISOLATED
   THUNDERSTORMS WILL BE POSSIBLE. SOME OF THESE STORMS MAY PRODUCE
   LOCALLY STRONG TO SEVERE DOWNBURSTS...ALONG WITH MARGINALLY SEVERE
   HAIL. SOME MODELS DO INDICATE A WEAK WAVE DEVELOPING ATOP THE UPPER
   RIDGE...WHICH COULD HELP FOCUS CONVECTION INTO A SMALL CLUSTER.
   
   ..JEWELL.. 05/25/2012
   
   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z