SPC AC 151729

   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1229 PM CDT MON AUG 15 2016

   VALID 161200Z - 171200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM A PORTION OF THE OH VALLEY
   INTO THE NERN STATES...

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM THE OH VALLEY THROUGH THE
   NERN STATES AND MID ATLANTIC...

   ...THERE IS A MRGL RISK OF SVR TSTMS OVER A PORTION OF THE UPPER MS
   VALLEY...

   ...SUMMARY...
   STRONG TO SEVERE STORMS WILL BE POSSIBLE FROM A PORTION OF THE OHIO
   VALLEY INTO THE NORTHEASTERN  STATES TUESDAY AFTERNOON AND EVENING
   WITH DAMAGING WIND THE MAIN THREAT. OTHER MORE ISOLATED STRONG TO
   SEVERE STORMS WILL BE POSSIBLE OVER A PART OF THE UPPER MISSISSIPPI
   VALLEY.

   ...SYNOPSIS...

   SRN STREAM SHORTWAVE TROUGH CURRENTLY OVER OK/KS WILL SHEAR NEWD
   INTO THE GREAT LAKES REGION...BECOMING ABSORBED WITHIN BELT OF
   MODEST NRN STREAM FLOW. THIS FEATURE WILL DEAMPLIFY TUESDAY AS IT
   CONTINUES THROUGH THE CONFLUENT FLOW REGIME ALONG NWRN PERIPHERY OF
   AN UPPER RIDGE. A WEAK SFC LOW WILL EVOLVE OVER THE GREAT LAKES IN
   RESPONSE THE DEAMPLIFYING SHORTWAVE TROUGH AND MOVE EWD ALONG A WARM
   FRONT THAT WILL EXTEND FROM THE LOWER GREAT LAKES INTO SRN NEW
   ENGLAND. A COLD FRONT WILL EXTEND SWWD FROM THE LOW THROUGH THE OH
   VALLEY AND INTO TX...BUT SWRN EXTENSION OF THIS BOUNDARY WILL REMAIN
   NEARLY STATIONARY.

   ...OH VALLEY THROUGH NERN SATES...

   A MOIST WARM SECTOR WILL RESIDE SOUTH OF WARM FRONT THAT MAY MOVE
   VERY SLOWLY NWD INTO SRN NEW ENGLAND DURING THE DAY. IT IS LIKELY
   THAT WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE ONGOING EARLY IN
   THE DAY WITHIN ZONE OF ISENTROPIC ASCENT NORTH OF THE WARM FRONT
   FROM THE LOWER GREAT LAKES INTO A PORTION OF THE NERN STATES. THIS
   ACTIVITY WILL SHIFT NEWD WITH TIME AS THE LLJ MIGRATES NEWD AND
   VEERS IN RESPONSE TO THE PREVIOUSLY MENTIONED PROGRESSIVE SHORTWAVE
   TROUGH. CURRENT INDICATIONS ARE THAT THE BOUNDARY LAYER WILL UNDERGO
   SOME DESTABILIZATION IN WARM SECTOR AS BREAKS IN CLOUDS OCCUR DURING
   THE DAY WITH LOW 70S DEWPOINTS AND TEMPERATURES RISING TO THE 80S
   SUPPORT MODERATE INSTABILITY...BUT MLCAPE SHOULD BE LIMITED TO
   GENERALLY AOB 1500 J/KG DUE TO WEAK MID-LEVEL LAPSE RATES. A BELT OF
   35-40 KT WINDS IN THE 700-500 MB LAYER WILL SPREAD THROUGH THE WARM
   SECTOR AND EFFECTIVE BULK SHEAR WILL INCREASE TO 35-40
   KT...ESPECIALLY IN VICINITY OF WARM FRONT. WIDELY SCATTERED TO
   SCATTERED STORMS ARE EXPECTED TO DEVELOP FROM THE OH VALLEY INTO THE
   NERN STATES WARM SECTOR AS THE WEAKLY CAPPED BOUNDARY LAYER
   DESTABILIZES.  DOMINANT STORM MODE WILL PROBABLY BE MULTICELLULAR IN
   CHARACTER IN MOST OF WARM SECTOR...BUT A FEW SUPERCELL STRUCTURES
   WILL BE POSSIBLE WITH STORMS DEVELOPING CLOSER TO AND INTERACTING
   WITH WARM FRONT WHERE BOTH LOW-LEVEL AND DEEP LAYER SHEAR WILL BE
   STRONGER.  DAMAGING WIND WILL BE THE MAIN THREAT...BUT A CONDITIONAL
   RISK ALSO EXISTS FOR A COUPLE OF TORNADOES. WILL MAINTAIN 15% SEVERE
   PROBABILITIES THIS UPDATE...BUT AN ENHANCED MIGHT BE INTRODUCED IN
   LATER UPDATES ONCE UNCERTAINTIES REGARDING THE EVOLUTION OF THE
   THERMODYNAMIC ENVIRONMENT HAVE BEEN MITIGATED.

   ...UPPER MS VALLEY...

   MODERATE INSTABILITY IS EXPECTED IN THIS REGION DOWNSTREAM FROM A
   LOW-AMPLITUDE SHORTWAVE TROUGH THAT WILL MOVE THROUGH THIS AREA
   DURING THE AFTERNOON.  THIS REGION WILL RESIDE ALONG ERN FRINGE OF
   STEEPER LAPSE RATE PLUME...BUT ONLY MODEST WINDS ALOFT AND VERTICAL
   SHEAR WILL ACCOMPANY THE MID-LEVEL WAVE. THUNDERSTORMS ARE EXPECTED
   TO REDEVELOP AS THE BOUNDARY LAYER DESTABILIZES. VERTICAL SHEAR FROM
   25-30 KT AND MLCAPE GENERALLY AROUND 2000 J/KG WILL SUPPORT
   POTENTIAL FOR A FEW MULTICELL STORMS TO PRODUCE LARGE HAIL AND
   ISOLATED DOWNBURST WINDS FROM MID AFTERNOON THROUGH EARLY EVENING.

   ..DIAL.. 08/15/2016

   CLICK TO GET WUUS02 PTSDY2 PRODUCT

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