SPC AC 171743
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1243 PM CDT WED AUG 17 2005
   
   VALID 181200Z - 191200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM MKG
   GRR 35 WNW FDY DAY LUK 40 SSE SDF BWG PAH CGI VIH 50 N SZL 55 ENE
   OMA FRM MKT MSP EAU CWA MTW MKG.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 SE IPL EDW FAT TVL
   RNO WMC OWY SUN BTM HLN LWT MLS DIK 70 NE MOT ...CONT... 40 NNW BUF
   PSB MRB CHO LYH DAN RDU GSB HSE ...CONT... LRD COT SAT AUS SHV 35
   ENE TXK FSM EMP BIE LNK OLU BUB BBW MCK EHA MAF 40 S P07.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SERN MN/IA TO WRN
   OH/NRN KY...
   
   ...SYNOPSIS...
   PROGRESSIVE NRN STREAM FLOW PATTERN WILL BE DOMINATED BY MID/UPPER
   LEVEL LOW NOW TAKING SHAPE OVER SRN BC AND PACIFIC NW. THIS FEATURE
   IS PROGGED TO TURN EWD ACROSS SRN ALTA AND SRN SASK THROUGH
   PERIOD...WITH ASSOCIATED TROUGH SWD INTO N-CENTRAL ROCKIES.  AS THIS
   GRADUALLY OCCURS...LEADING SHORTWAVE TROUGH -- NOW EVIDENT IN
   VWP/PROFILER DATA AND MOISTURE CHANNEL IMAGERY OVER ERN WY -- IS
   EXPECTED TO EJECT EWD OVER UPPER MS VALLEY AND LM REGION.
   
   QUASISTATIONARY SFC FRONTAL ZONE -- NOW ANALYZED ACROSS NRN/ERN
   MT...SRN ND AND NRN MN -- IS EXPECTED TO BECOME COLD FRONT AS NWRN
   TROUGH/LOW APCH AREA...MOVING SEWD ACROSS NRN/CENTRAL PLAINS AND NRN
   MN.  ATTACHED SFC LOW SHOULD MOVE EWD ACROSS NRN MN...WHILE MIDLEVEL
   TROUGH MOVES OVHD.  WARM FRONT SHOULD LIFT NWD OVER PORTIONS
   IA/WI/IL/LM AND LOWER MI THROUGH PERIOD.
   
   ...MID MS VALLEY...SRN GREAT LAKES...LOWER OH VALLEY...
   STRONGEST DEEP-LAYER ASCENT IS EXPECTED TO OCCUR INVOF SFC LOW...AND
   ALONG AND N OF WARM FRONT OVER UPPER MIDWEST.  HOWEVER...TIGHTEST
   FLOW GRADIENTS ALOFT AND STRONGEST DEEP-LAYER SHEAR IS EXPECTED TO
   BE GENERALLY S OF SFC WARM FRONT ACROSS WARM SECTOR...FROM ERN IA
   ACROSS WRN IL BY AFTERNOON.  HORIZONTAL DISPLACEMENT BETWEEN
   STRONGEST PROGGED LIFT AND STRONGEST BUOYANCY/SHEAR LENDS SOME
   UNCERTAINTY ABOUT LOCATION/COVERAGE OF CONVECTION..AND WHERE TO
   ASSIGN HIGHER PROBABILITIES WITHIN BROAD 15% ENVELOPE. 
   HOWEVER...WEAK CAP IS EVIDENT IN MODIFIED ETA FCST
   SOUNDINGS...SUGGESTING ANY CONVECTION THAT DOES DEVELOP WILL BECOME
   SEVERE WITH DAMAGING GUSTS, HAIL AND A FEW TORNADOES POSSIBLE. 
   ALSO...OUTFLOW BOUNDARY FROM POSSIBLE MCS OVERNIGHT DAY-1 MAY MAKE
   PROFILES MORE FAVORABLE ON MESOSCALE AND OPTIMAL SEVERE THREAT AREA
   MORE PRECISELY DEFINED.
   
   GREATEST SUPERCELL POTENTIAL SHOULD BE INVOF WARM FRONT OR OUTFLOW
   BOUNDARY WHERE SFC FLOW IS MOST STRONGLY BACKED...OPTIMALLY
   ENLARGING LOW LEVEL HODOGRAPHS WHERE THERE STILL IS SUBSTANTIAL
   SFC-BASED INSTABILITY. MODIFIED MODEL SOUNDINGS SHOW 0-1 KM SRH
   200-300 J/KG NEAR WARM FRONT...AND A STILL-FAVORABLE 100-200 J/KG
   SWD TOWARD NERN MO/WRN IL DESPITE NEARLY UNIDIRECTIONAL DEEP-LAYER
   FLOW S OF WARM FRONT.  WARM SECTOR EFFECTIVE SHEARS MAY REACH 45-50
   KT.  BUOYANCY WILL BE MAXIMIZED S OF WARM FRONT...AS VERY RICH
   BOUNDARY LAYER MOISTURE AND SFC DIABATIC HEATING CONTRIBUTE TO
   MLCAPES 2000-3000 J/KG.  STRONGEST DEEP-LAYER SHEAR WILL SHIFT EWD
   ACROSS IL/INDIANA DURING EVENING AND OVERNIGHT.
   
   AFTERNOON ACTIVITY MAY EVOLVE INTO EVENING/OVERNIGHT COMPLEX THAT
   WOULD MOVE ACROSS PORTIONS IL/WI/LM AND POSSIBLY LOWER MI BEFORE
   WEAKENING.  DAMAGING GUSTS AND OCCASIONAL HAIL ARE POSSIBLE.
   
   ...UPPER MIDWEST TO WY...
   SCATTERED TO WIDELY SCATTERED TSTMS ALSO ARE POSSIBLE ALONG AND
   BEHIND FCST SFC COLD FRONT...WITH ACTIVITY OVER ERN WY/SERN MT AIDED
   BY POSTFRONTAL UPSLOPE COMPONENT TO BOUNDARY LAYER WINDS. 
   DEEP-LAYER SHEAR WILL BE FAVORABLE AND INCREASING THROUGHOUT DAY
   WITH APCH OF STRONG NWRN TROUGH...I.E. 50-60 KT OF 0-6 KM AND
   EFFECTIVE SHEARS PROGGED IN NERN WY.  ALTHOUGH LOW LEVEL MOISTURE
   AND INSTABILITY WILL BE MORE LIMITED IN THIS AREA...STEEPENING
   MIDLEVEL LAPSE RATES MAY YIELD ENOUGH BUOYANCY TO SUPPORT HAIL/WIND
   THREAT WITH STRONGER CELLS.
   
   ..EDWARDS.. 08/17/2005
   
   ...NOTICE...
   THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
   SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
   WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
   IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
   CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
   WILL PROVIDE DETAILS ON THE TRANSITION.
   
   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0800Z