SPC AC 271741
   
   DAY 2 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1241 PM CDT FRI AUG 27 2004
   
   VALID 281200Z - 291200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 WNW
   ROC 25 SW BFD 20 NNE PKB 20 WNW LEX 30 WSW EVV 40 SSE SPI 35 ESE CGX
   70 N MTC.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 75 SSW
   GDP 40 NW GDP 25 N HOB 25 NW BGS 30 WNW SJT 70 SW SJT 25 SE P07.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 SW DMN 45 SSE FMN
   55 WNW COS 15 SW RWL 30 WNW PIH 45 N BKE 35 NNW 4OM ...CONT... 50 W
   RRT 10 NE MBG 30 SW RAP 30 WNW SNY 25 WNW EHA 30 NNE PVW 30 W LTS 25
   SE END 55 SW SZL 20 NE IRK 35 S OSH 10 NNE APN ...CONT... 35 NNE HYA
   15 S POU CXY 40 WSW SHD 35 S PSK 40 ENE CLT 10 NNW HSE.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE LOWER OH
   VALLEY/MIDWEST AREA TO LOWER GREAT LAKES...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SOUTHWEST TX...
   
   ...SYNOPSIS...
   HEIGHT FALLS...ALTHOUGH WEAK...ARE EXPECTED ON SATURDAY FROM THE SRN
   PLAINS TO THE OH VALLEY/GREAT LAKES REGION AS UPPER TROUGH MOVES EWD
   ACROSS THE UPPER MS VALLEY/WRN GREAT LAKES AND MID MS VALLEY TO SRN
   PLAINS.  THE PROGRESSIVE NATURE OF THE UPPER TROUGH/FLOW PATTERN
   APPEARS LIKELY...AS UPSTREAM TROUGH /CURRENTLY LOCATED ALONG THE BC
   COAST/ PHASES WITH TROUGH OVER NRN CANADA AND AMPLIFIES ACROSS
   CENTRAL CANADA AND THE NRN PLAINS ON DAY 2.
   
   COLD FRONT PROGGED TO INITIALLY EXTEND FROM ERN QUEBEC/LOWER GREAT
   LAKES SWWD ACROSS SRN LOWER MI TO NRN IL TO CENTRAL OK AND WEST
   CENTRAL TX WILL ADVANCE EAST AND SOUTH.  THE CENTRAL/SRN PARTS OF
   THIS BOUNDARY SHOULD REACH FAR NWRN OH TO CENTRAL AR AND CENTRAL TX
   BY 00Z.  A SURFACE WAVE LOCATED OVER NRN IL AT 12Z SATURDAY WILL
   MOVE ENEWD ALONG THE FRONT TO FAR NWRN OH BY 00Z...BEFORE MOVING
   ACROSS THE LOWER GREAT LAKES SATURDAY NIGHT.
   
   ...OH VALLEY/LOWER GREAT LAKES...
   LEAD SHORT WAVE TROUGH...CURRENTLY LOCATED OVER ERN CO AND AHEAD OF
   MAIN UPPER TROUGH...WILL MOVE EWD ACROSS THE MIDWEST TO MID MS
   VALLEY/OZARKS. LARGE SCALE ASCENT WITH THIS FEATURE AND WITHIN THE
   ENTRANCE REGION OF 130-140 KT SWLY UPPER LEVEL JET WHICH WILL EXTEND
   FROM UPPER GREAT LAKES TO ERN CANADA IS EXPECTED TO AID IN
   CONVECTIVE DEVELOPMENT ON DAY 2 ALONG THE COLD FRONT.  SWLY
   LOW-LEVEL FLOW IN ADVANCE OF THE COLD FRONT WILL MAINTAIN A VERY
   MOIST AIR MASS /SURFACE DEWPOINTS IN THE LOWER 70S/ ACROSS THE WARM
   SECTOR.
   
   THUNDERSTORMS IN THE FORM OF AT LEAST TWO MCS/S ARE EXPECTED TO BE
   ONGOING AT THE START OF THE FORECAST PERIOD ACROSS THE SRN GREAT
   LAKES/LOWER OH VALLEY AND THE SRN PLAINS.  MODELS SUGGEST...
   ESPECIALLY THE 27/09Z ETAKF...THAT ENOUGH CLEARING IN THE WAKE OF
   LOWER OH VALLEY MORNING CONVECTION SHOULD OCCUR AND ALLOW FOR
   SUFFICIENT DESTABILIZATION...GIVEN MODEST LAPSE RATES /AROUND 6.5
   C/KM/. INCREASING DEEP LAYER ASCENT SATURDAY AFTERNOON ASSOCIATED
   WITH AFOREMENTIONED UPPER FEATURES AND LOW-LEVEL CONVERGENCE AS THE
   COLD FRONT MOVES EWD INTO THE MODERATELY UNSTABLE AIR MASS SHOULD
   RESULT IN NEW STORMS FROM SERN MO TO NWRN IND/SRN LOWER MI.
   DEEP LAYER SHEAR VALUES SUPPORT MULTICELLS AND ISOLATED SUPERCELLS
   WITH ACTIVITY MOST LIKELY IN THE FORM OF A BROKEN LINE ALONG THE
   FRONT.
   
   AS THE LEAD SHORT WAVE AND COLD FRONT MOVE EWD ACROSS THE MIDWEST/
   OH VALLEY...THE THREAT FOR SEVERE STORMS WILL CONTINUE INTO THE
   EARLY EVENING BEFORE ACTIVITY WEAKENS WITH THE LOSS OF DAY TIME
   HEATING STABILIZING THE ENVIRONMENT.
   
   ...SW TX...
   COLD FRONT WILL MOVE SWD ACROSS SWRN TX...WITH ENELY LOW-LEVEL WINDS
   IN ITS WAKE ADVECTING LOWER-MIDDLE 60S SURFACE DEWPOINTS INTO THIS
   REGION.  STEEP LAPSE RATES ATOP THIS LOW-LEVEL MOISTURE WILL RESULT
   IN MODERATE INSTABILITY /MLCAPE 1500-2500 J/KG/ FROM SERN NM INTO
   SWRN TX.  DESPITE MODEST NWLY MID-LEVEL FLOW /20-25 KT/...ENELY
   LOW-LEVEL WINDS WILL ENHANCE DEEP LAYER SHEAR FOR MULTICELLS AND A
   FEW SUPERCELLS AS THUNDERSTORMS DEVELOP ALONG AND JUST NORTH OF THE
   COLD FRONT.  HAIL AND DAMAGING WIND GUSTS SHOULD BE THE PRIMARY
   THREATS.
   
   ...NRN NEW ENGLAND...
   MODERATE /40 KT/ DEEP WLY SHEAR WILL OVERSPREAD NRN NEW ENGLAND ON
   SATURDAY ALONG SRN FRINGE OF STRONG UPPER IMPULSE CROSSING QUEBEC.
   HOWEVER...MEAN WLY FLOW WILL KEEP CONVERGENCE WEAK ALONG ASSOCIATED
   COLD FRONT DROPPING S INTO NRN PORTIONS OF ME/NH/VT.  COUPLED WITH
   WARM TEMPERATURES IN THE 700-600 MB LAYER DUE TO RIDGING OFF THE ERN
   SEABOARD...POTENTIAL FOR SUSTAINED STORMS AND SEVERE WEATHER SHOULD
   REMAIN LIMITED.
   
   ..PETERS.. 08/27/2004
   
   ...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 2 OUTLOOK IS SCHEDULED FOR 0800Z