SPC AC 091718

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1218 PM CDT TUE SEP 09 2014

   VALID 101200Z - 111200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM LOWER MI TO PORTIONS OF
   MO...

   ...SUMMARY...
   STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A COLD FRONT FROM
   LOWER MICHIGAN...SOUTHWEST INTO MISSOURI.  DAMAGING WINDS ARE THE
   PRIMARY THREAT WITH THIS FRONTAL CONVECTION.

   ...LOWER MI TO MO...

   CONSIDERABLE DIFFERENCES HAVE DEVELOPED WITHIN LATEST SHORT-RANGE
   MODEL GUIDANCE...SPECIFICALLY THE NAM DEEPENING A CYCLONE OVER THE
   UPPER GREAT LAKES DURING THE DAY WEDNESDAY.  GFS/ECMWF ARE
   CONSIDERABLY FLATTER WITH MID-LEVEL SHORT-WAVE AND SUBSEQUENTLY SFC
   LOW IS MUCH WEAKER AS IT TRACKS FROM SRN WI INTO NRN LOWER MI BY MID
   AFTERNOON.  INSTABILITY WILL LIKELY BE A MAJOR CONCERN DURING THE
   DAY2 PERIOD AS VERY WARM MID-LEVEL TEMPERATURES WILL OVERSPREAD THE
   PRE-FRONTAL ENVIRONMENT AND FORECAST LAPSE RATES REFLECT THIS
   WARMING WITH VALUES ON THE ORDER OF 6 C/KM.  ADDITIONALLY...VERY
   MOIST PROFILES ARE EXPECTED TO SPREAD NEWD AHEAD OF THE FRONT WITH
   PW OF 2-2.25 IN.

   EARLY IN THE PERIOD NUMEROUS SHOWERS/THUNDERSTORMS WILL BE ONGOING
   ALONG/AHEAD OF COLD FRONT ACROSS THE UPPER GREAT LAKES...SWWD INTO
   THE MID MS VALLEY.  THIS ACTIVITY SHOULD SPREAD ENEWD DURING THE DAY
   WITHIN A STRONGLY SHEARED ENVIRONMENT.  LATEST THINKING IS AN
   ORGANIZED SQUALL LINE...OR MULTIPLE SHORT LINE SEGMENTS...WILL BE
   THE PRIMARY STORM MODE WITHIN DEEP SWLY FLOW REGIME.  PER ABOVE
   REASONING...EXTENSIVE CLOUDS/PRECIP SHOULD LIMIT SFC HEATING AND
   LAPSE RATES...THUS UPDRAFTS SHOULD BE HAMPERED SOMEWHAT.  EVEN
   SO...STRONG WIND FIELDS SUGGEST DAMAGING WINDS MAY ACCOMPANY
   ORGANIZED LINE SEGMENTS WITH THE MOST LIKELY CORRIDOR FOR STRONG
   WINDS ACROSS PORTIONS OF IL/INDIANA WHERE GREATER DIABATIC HEATING
   IS EXPECTED.

   ..DARROW.. 09/09/2014

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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z