SPC AC 070730

   DAY 3 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0230 AM CDT SUN JUL 07 2013

   VALID 091200Z - 101200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM A PORTION OF THE CNTRL AND
   NRN PLAINS INTO THE UPPER MS VALLEY AND WRN GREAT LAKES...

   ...SYNOPSIS...

   TYPICAL SUMMER SYNOPTIC PATTERN WITH EXPANSIVE UPPER RIDGE OVER THE
   SRN TWO THIRDS OF THE COUNTRY AND BELT OF STRONGER WLYS OVER THE NRN
   TIER STATES WILL PREVAIL TUESDAY. A LOW AMPLITUDE SHORTWAVE TROUGH
   EMBEDDED WITHIN THIS BELT OF STRONGER FLOW IS FORECAST TO MOVE FROM
   ERN MT EARLY TUESDAY TO THE WRN GREAT LAKES BY THE END OF THE
   PERIOD. THERE IS ALSO SOME INDICATION AMONG MODELS THAT AN MCV OR
   TWO MIGHT DEVELOP AHEAD OF THE SHORTWAVE TROUGH IN ASSOCIATION WITH
   ONGOING CONVECTION. AT THE SFC A QUASISTATIONARY FRONT /PORTIONS OF
   WHICH MAY BE CONVECTIVELY REINFORCED/ WILL LINGER FROM THE GREAT
   LAKES WWD THROUGH IA AND NEB. THE NRN STREAM SHORTWAVE TROUGH WILL
   PROVIDE THE IMPETUS FOR A COLD FRONT TO ACCELERATE SEWD THROUGH THE
   NRN/CNTRL PLAINS AND UPPER MS VALLEY. BY THE END OF THE PERIOD THIS
   BOUNDARY IS FORECAST TO EXTEND FROM THE GREAT LAKES SWWD THROUGH KS.


   ...CNTRL/NRN PLAINS THROUGH UPPER MS VALLEY AND GREAT LAKES...

   MAIN COMPLICATING FACTOR THIS FORECAST IS POTENTIAL FOR WIDESPREAD
   CONVECTION TO BE ONGOING EARLY TUESDAY. MCS MAY BE IN PROGRESS FROM
   ND INTO NRN MN AND FARTHER SOUTH FROM IA INTO THE SRN GREAT LAKES OR
   NRN OH VALLEY WITHIN A BROAD ZONE OF WARM ADVECTION. THIS ACTIVITY
   SHOULD CONTINUE EAST ALLOWING POTENTIAL FOR THE UPSTREAM BOUNDARY
   LAYER TO DESTABILIZE. WHILE SOME CONVECTIVE DEBRIS MIGHT LINGER A
   PORTION OF THE DAY...AT LEAST PARTIAL CLEARING SHOULD DEVELOP FROM
   THE WEST. A BROAD FETCH OF MULTI-DAY SLY WINDS AND
   EVAPOTRANSPIRATION WILL CONTRIBUTE TO UPPER 60S DEWPOINTS IN
   PRE-FRONTAL WARM SECTOR...WHILE PLUME OF STEEPER LAPSE RATES ADVECT
   EWD ABOVE THE MOIST AXIS. ASSUMING THE EARLY CONVECTION IS NOT TOO
   WIDESPREAD AND CONTINUES EAST...POTENTIAL WILL EXIST FOR A RESERVOIR
   OF STRONG INSTABILITY TO DEVELOP FROM ERN NEB...SERN SD...SRN MN
   INTO IA WITH MLCAPE FROM 2000-3000 J/KG POSSIBLE.

   STORMS SHOULD REDEVELOP DURING THE AFTERNOON ALONG RESIDUAL
   PRE-FRONTAL OUTFLOW BOUNDARIES AND SEWD ADVANCING COLD FRONT. THIS
   REGION WILL EXIST WITHIN BELT OF MODERATE WLY FLOW AOA 500 MB WITH
   30-45 KT EFFECTIVE SHEAR SUPPORTIVE OF ORGANIZED STORMS INCLUDING
   SUPERCELLS AND LINES WITH BOWING SEGMENTS. DAMAGING WIND AND LARGE
   HAIL WILL BE THE MAIN THREATS...BUT A CONDITIONAL THREAT WILL ALSO
   EXIST FOR ISOLATED TORNADOES...ESPECIALLY OVER THE UPPER MS VALLEY
   REGION.

   ..DIAL.. 07/07/2013

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

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