SPC AC 262017
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0317 PM CDT THU AUG 26 2004
   
   VALID 262000Z - 271200Z
   
   THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 W
   OTM 40 ESE OMA 25 NNE OMA 50 E SUX 30 ESE SPW 35 ENE MCW 50 SSW LSE
   20 WSW DBQ 30 WNW MLI 25 W OTM.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM OSC
   FNT JXN 45 NW MIE HUF 30 NNE SLO ALN COU OJC TOP 10 S BIE 25 SSE OLU
   15 SE OFK 35 N SUX 10 SSE OTG 15 NW MKT 30 NNE MSP 45 S DLH 25 ENE
   DLH.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 S VCT 50 NNW VCT
   15 SSE TPL 40 ESE DAL 20 W PRX 10 ENE MLC 50 E OKC 30 SE FSI 30 NNE
   BWD 35 S SJT 25 ESE P07 ...CONT... 70 SSW GDP 35 SW INK 45 NNW BGS
   35 SSW CDS 35 ESE GAG 30 SE P28 30 ESE SLN 25 SE HSI 15 NNE MCK 20
   NNE LIC 10 NW COS 30 ENE GJT 55 WNW PUC 40 S OWY 65 NNW BNO 15 W DLS
   40 SSE OLM 40 ESE SEA 25 NE BLI ...CONT... 10 NNW ART 40 WNW IPT 25
   WNW SHD 35 NE HKY 15 W AND 25 WNW AGS 30 WSW SOP FAY 20 N HSE.
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS A LARGE PORTION OF IA...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID AND UPPER MS
   VALLEY TO THE WRN GREAT LAKES...
   
   ...NORTH CENTRAL U.S...
   EARLY AFTERNOON SURFACE ANALYSES SHOWED A COLD FRONT CONTINUING TO
   MOVE SLOWLY EWD...AND EXTENDED AT 18Z FROM WRN WI SWWD TO NWRN
   IA/NERN NEB TO A SURFACE LOW OVER FAR NORTH CENTRAL KS...AND THEN
   WWD INTO CENTRAL CO.  A DRY LINE EXTENDED FROM WRN TX/WRN OK NNEWD
   TO THE KS SURFACE LOW. MEANWHILE...AN OUTFLOW BOUNDARY EXTENDED
   FROM SRN IL NNWWD INTO ERN IA. VERY MOIST SLY LOW-LEVEL FLOW TO THE
   EAST OF THE SURFACE LOW WILL DESTABILIZE THE WARM SECTOR FURTHER AS
   SURFACE DEWPOINTS RISE THROUGH THE MID 70S.  18Z OMA SOUNDING SHOWS
   AIR MASS REMAINS CAPPED.  STEEP LAPSE RATES /7-7.5 C/KM/ ATOP THIS
   MOISTURE AND CONTINUED SURFACE HEATING WILL FURTHER DESTABILIZE THE
   AIR MASS WITH THE POTENTIAL FOR A VERY UNSTABLE TO LOCALLY EXTREME
   INSTABILITY ACROSS THE MODERATE RISK AREA AND SWD INTO NRN MO AND
   NRN/CENTRAL IL.  
   
   VIS IMAGERY SHOWS A FEW CU DEVELOPING ALONG THE COLD FRONT...BUT
   MORE RAPID SURFACE DEVELOPMENT IS EXPECTED LATER THIS AFTERNOON INTO
   THE EVENING ACROSS THE MID MO RIVER VALLEY INTO IA AND EVENTUALLY
   NEWD INTO WI AS LARGE SCALE ASCENT INCREASES WITH THE APPROACH OF A
   SHORT WAVE TROUGH... CURRENTLY OVER SD/WRN NEB.  18Z OMA SOUNDING
   ALSO SHOWED LOWER TROPOSPHERE WINDS HAVE BACKED TO SSELY IN RESPONSE
   TO THE SHORT WAVE TROUGH...WITH HODOGRAPH BECOMING MORE FAVORABLE
   FOR SUPERCELLS WITH 0-3 KM SRH AROUND 200 M2/S2.  GIVEN POTENTIAL
   VERY TO EXTREMELY UNSTABLE AIR MASS AND DEEP LAYER SHEAR INCREASING
   TO 40-50 KT... TORNADOES WILL BE POSSIBLE ALONG WITH LARGE HAIL AND
   DAMAGING WINDS WITH THE INITIAL ACTIVITY.  
   
   AS A SWLY LLJ STRENGTHENS THIS EVENING/OVERNIGHT TO 40 KT FROM ERN
   KS TO SRN WI...CONVECTION WILL LIKELY EVOLVE INTO A BROKEN LINE OF
   STRONG TO SEVERE STORMS FROM IA INTO WI.  SEVERE THREAT SHOULD
   EVOLVE INTO MORE OF A DAMAGING WIND POTENTIAL WITH STORMS SPREADING
   EWD OVERNIGHT INTO PORTIONS OF MI AND NRN IL.
     
   ...SERN WY/NRN CO...
   AIR MASS WILL SLOWLY DESTABILIZE INTO THE EARLY EVENING AS COLD
   MID-LEVEL TEMPERATURES /-12 TO -16C AT 500 MB/ SPREAD ACROSS WY/NRN
   CO.  THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER THE HIGHER TERRAIN
   OF SERN WY/NRN CO...WITH STRONG DEEP LAYER SHEAR AND STEEP LAPSE
   RATES SUPPORTING A FEW STRONG WIND GUSTS AND HAIL.  HOWEVER...WEAK
   INSTABILITY WILL LIMIT THE SEVERE POTENTIAL.
   
   ..PETERS.. 08/26/2004
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED FOR 0100Z