MESOSCALE DISCUSSION 2016
   NWS STORM PREDICTION CENTER NORMAN OK
   0209 PM CDT THU AUG 18 2005
   
   AREAS AFFECTED...PORTIONS NERN AND EXTREME E-CENTRAL IA...NWRN
   IL...SWRN/S-CENTRAL WI...EXTREME SERN MN
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 181909Z - 182045Z
   
   WW MAY BE REQUIRED ACROSS SOME PORTION OF THIS REGION...WITH SEVERE
   POTENTIAL INCREASING OVER NEXT FEW HOURS.  DAMAGING
   GUSTS...TORNADOES AND OCCASIONAL LARGE HAIL ARE POSSIBLE.
   
   SFC MESOANALYSIS SHOWS WELL-DEFINED LOW OVER SERN MN -- N RST AS OF
   19Z -- FCST TO MOVE EWD INTO SWRN/S-CENTRAL WI THROUGH REMAINDER
   AFTERNOON.  WARM FRONT EXTENDS SEWD FROM LOW ACROSS SWRN WI INTO
   OUTFLOW POOL LEFT BY MORNING MCS.  WARM FRONT WILL CONTINUE LIFTING
   NWD AND WRN PORTION OF OLD OUTFLOW POOL WILL FAVORABLY MODIFY. 80S
   SFC TEMPS AND 70S DEW POINTS -- EVIDENT IN WARM SECTOR ALONG AND S
   OF WARM FRONT AND OUTFLOW BOUNDARY -- SHOULD SUPPORT MLCAPES AROUND
   2000 J/KG BASED ON MODIFIED RUC SOUNDINGS.  LOW LEVEL VERTICAL SHEAR
   PROFILES SHOULD REMAIN MAXIMIZED INVOF WARM FRONT...WHERE BACKED SFC
   WINDS CONTRIBUTE TO ENLARGED LOW LEVEL HODOGRAPHS AND 0-1 KM SRH OF
   150-250 J/KG SRH IN 0-1 KM AGL LAYER.  THOSE VALUES -- DERIVED FROM
   OBSERVED REGIONAL VWP DATA...ARE SUBSTANTIALLY HIGHER THAN INDICATED
   BY SHORT TERM RUC ANALYSES AND FCSTS...AND SUPPORT SUPERCELL/TORNADO
   THREAT PARTICULARLY NEAR WARM FRONT.
   
   FARTHER S...ISALLOBARICALLY FORCED VEERING OF SFC FLOW OVER MUCH OF
   IA SHOULD SHIFT EWD INTO IL THIS AFTERNOON S OF OUTFLOW
   BOUNDARY...LIMITING CONVERGENCE AND LOW LEVEL SHEAR...HOWEVER SEVERE
   GUSTS AND HAIL WILL BE POSSIBLE.
   
   IN IMMEDIATE VICINITY OF LOW/MIDDLE LEVEL CYCLONE OVER SERN MN...0-1
   KM SRH APPEARS SMALL BECAUSE OF WEAKER FLOW...HOWEVER VERY LOCALIZED
   AREA OF JUXTAPOSITION EXISTS BETWEEN FAVORABLE SFC VORTICITY MAX AND
   LOW LEVEL CAPE FIELD.  POSSIBILITY OF NONSUPERCELL TORNADOES CANNOT
   BE RULED OUT AS THAT REGIME SHIFTS EWD ACROSS REMAINDER EXTREME SERN
   MN AND LSE REGION INTO SWRN WI.
   
   ..EDWARDS.. 08/18/2005
   
   
   ATTN...WFO...GRB...LOT...ILX...MKX...DVN...ARX...DMX...
   
   41189032 41939139 42939212 43919236 44279184 44479098
   44469000 44378957 44098911 43708862 43128861 42498873
   41408896 41098934