MESOSCALE DISCUSSION 2022
   NWS STORM PREDICTION CENTER NORMAN OK
   0141 PM CDT WED SEP 26 2007
   
   AREAS AFFECTED...FAR ERN SD...WRN/CENTRAL MN...FAR NERN NEB AND NWRN
   IA
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 261841Z - 261945Z
   
   SCT TSTMS ARE EXPECTED TO DEVELOP AHEAD OF A SFC TROUGH IN THE NEXT
   2-3 HRS. A FEW OF THESE TSTMS MAY POSE A MARGINAL SVR WIND/HAIL
   THREAT WHILE MOVING QUICKLY EWD.
   
   LATEST SFC ANALYSIS SHOWS A NARROW INSTABILITY AXIS HAS DEVELOPED
   ACROSS FAR ERN SD/WRN MN...NERN NEB AND NWRN IA AHEAD OF A SFC
   TROUGH. PER VIS/WV SAT IMAGERY...THE LEADING EDGE OF THE STRONGER
   HEIGHT FALLS/MID LEVEL COOLING WAS MOVING EWD AROUND 35 KTS ACROSS
   CENTRAL SD. EXTRAPOLATION OF THIS MOTION TAKES THIS COOLING OVER THE
   WRN EDGE OF THE INSTABILITY AXIS AROUND 20Z. WITH A FEW MORE HRS OF
   HEATING...500-750 J/KG OF SBCAPE AND MINIMAL CINH WILL REMAIN BY 20Z
   PER 18Z RUC FORECAST SOUNDINGS. MARGINAL MID LEVEL FLOW CLOSER TO
   THE VORT CENTER OVER CENTRAL MN/ECENTRAL SD SHOULD LIMIT VERTICAL
   SHEAR. ALTHOUGH STEEP MID LEVEL LAPSE RATES MAY SUPPORT ISOLATED SVR
   HAIL THREAT. FURTHER SOUTH...STRONGER MID LVL FLOW OVER SERN SD/NERN
   NEB...SWRN MN AND NWRN IA MAY SUPPORT A FEW ORGANIZED LINE SEGMENTS.
   SUFFICIENT VERTICAL SHEAR WILL BE PRESENT TO SUPPORT AT LEAST AN
   ISOLATED SVR WIND/HAIL THREAT WITH THE STRONGEST TSTMS. MAIN
   LIMITING FACTOR FOR A GREATER SVR THREAT WILL BE MARGINAL
   INSTABILITY.
   
   ..CROSBIE.. 09/26/2007
   
   
   ATTN...WFO...MPX...DMX...FGF...FSD...OAX...ABR...
   
   45699673 44409725 42849797 42419802 41919737 41849662
   42409550 43749456 45219427 45849461 45979588