SPC AC 200102
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0802 PM CDT THU MAY 19 2005
   
   VALID 200100Z - 201200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM HSS
   RMG 40 S MSL TUP UOX 40 SW JBR UNO TBN JEF 25 NW UIN PIA RFD 35 ENE
   RFD CGX 25 SE CGX 10 E SBN CMH UNI 30 E 5I3 HSS.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM AQQ 40 NNW CEW LUL
   HEZ 30 NNE SHV PRX 30 WNW ADM 45 SW END ICT MKC MLI LNR MSN MKG MTC
   DUJ DOV 40 E SBY ...CONT... 45 SSW CHS SAV 30 ESE AYS GNV 50 W ORL
   SRQ.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 80 N GFK GFK 50 NW
   ABR PHP DGW 50 S TWF OWY BNO RDM EUG 40 NW OTH.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS MUCH OF INDIANA/IL SEWD TO SRN
   APPALACHIANS AND SWWD TO ERN OZARK REGION...
   
   ...SYNOPSIS...
   DOMINANT LARGE SCALE FEATURE REMAINS ANTICYCLONE OVER SWRN DESERTS
   --- WITH RIDGE NEWD ACROSS N-CENTRAL PLAINS TO HUDSON BAY.  AS
   HEIGHTS BEGIN BUILDING E OF THAT RIDGE...PRONOUNCED UPPER LOW NOW
   OVER WI/IL BORDER REGION WILL MOVE SEWD...CROSSING OH VALLEY AT
   INDIANA/KY BORDER BY END OF PERIOD.  THIS WILL STRENGTHEN AND VEER
   MID/UPPER LEVEL FLOW TO NWLY OR NNWLY OVER MID/LOWER MS VALLEY
   REGION.
   
   AT SFC...VERY COMPLEX PATTERN IS ANALYZED AND ONLY SUMMARIZED HERE. 
   SYNOPTIC WARM FRONT LOOSELY EXTENDS FROM LOWER CHESAPEAKE/TIDEWATER
   REGION WNWWD ACROSS N-CENTRAL APPALACHIANS AND INDIANA TO SFC LOW
   OVER NRN IL...WITH WEAK COLD FRONT OVER NERN MO...NERN KS AND SWRN
   NEB.  SFC CYCLONE SHOULD REDEVELOP EWD ALONG FRONTAL ZONE OVER WV
   LATE TONIGHT...WITH WARM FRONT REVERSING COURSE AND MOVING OVER KY
   AS COLD FRONT -- REINFORCED BY CONVECTIVE OUTFLOWS. NUMEROUS
   MESOSCALE OUTFLOW BOUNDARIES ARE ANALYZED BETWEEN NRN/WRN NC AND NRN
   IL...EFFECTIVELY ADJUSTING FRONTAL ZONE SWD IN SEGMENTED FASHION. 
   VERY WEAK/RESIDUAL FRONT ALSO IS EVIDENT IN SFC ANALYSIS AND VIS
   IMAGERY FROM SRN IL WSWWD ACROSS OZARKS TO SWRN KS AND N-CENTRAL
   OK...INTERSECTING DRYLINE OVER NWRN OK.
   
   ...GREAT LAKES STATES...LOWER OH AND MID MS VALLEYS...
   SEVERAL CLUSTERS OF STRONG AND SEVERE TSTMS ARE ONGOING AND WILL
   CONTINUE TO POSE POTENTIAL FOR DAMAGING WIND AND LARGE HAIL FROM
   NERN TN/ERN KY NWWD INTO IL.  REF FOLLOWING SPC WATCHES --
   289..290...292...293...294 -- ALONG WITH LATEST RELATED MESOSCALE
   DISCUSSIONS...FOR SHORT-TERM FCST DETAILS ON THIS SITUATION.
   
   TWO MCS SCENARIOS APPEAR MOST PROBABLE ATTM...
   1. EVOLUTION OF LARGE KY CLUSTER AND SEWD MOTION ACROSS REMAINDER
   CENTRAL/ERN KY AND ERN TN...SEVERE POTENTIAL DIMINISHING SWD AS
   INSTABILITY WEAKENS WITH TIME.
   2. ACTIVITY OVER NRN IL AND NWRN INDIANA MAY BACKBUILD WWD AS IT
   MOVES SEWD...RESULTING IN NET SWD MOTION IN GOOD AGREEMENT WITH LAST
   SEVERAL ETA RUNS OF CORFIDI MCS MOTION VECTORS.  CONVECTION THEN
   SHOULD MOVE ACROSS REMAINDER IL/INDIANA INTO WRN KY/TN AND PERHAPS
   ERN  MO...ALONG AND W OF OUTFLOW FROM NUMBER 1.
   
   DAMAGING WIND APPEARS TO BE PRIMARY THREAT CONSIDERING VERY DRY LOW
   LEVEL AIR MASS EVIDENT IN ILX RAOB.  SOMEWHAT RICHER MOISTURE
   EVIDENT FARTHER S FROM OZARKS TO TN VALLEY...S OF WEAK/SRN
   FRONT...WITH MLCAPES 500-1500 J/KG.
   
   ...SRN PLAINS...
   WEAK CONVERGENCE AND RELATIVELY STRONG CAPPING HAVE PRECLUDED
   ORGANIZED/DEEP CONVECTIVE DEVELOPMENT ALONG/S OF WEAK SRN FRONT AND
   E OF DRYLINE...DESPITE POCKETS OF FAVORABLE LOW LEVEL MOISTURE WITH
   MID 60S-LOW 70S F DEW POINTS.  ISOLATED AND VERY CONDITIONAL SEVERE
   POTENTIAL REMAINS FOR ANOTHER FEW HOURS OVER ERN OK...ESPECIALLY
   INVOF RESIDUAL N-S OUTFLOW BOUNDARY FROM MORNING CONVECTION. 
   HOWEVER...COMBINATION OF LOSS OF DIURNAL HEATING...WEAK LOW LEVEL
   CONVERGENCE AND BUILDING HEIGHTS ALOFT SUGGEST PROBABILITIES HAVE
   MARGINALIZED TO BELOW CATEGORICAL THRESHOLDS.
   
   ....NRN PLAINS...
   ISOLATED STRONG-SEVERE TSTMS POSSIBLE ANOTHER 2-3 HOURS OVER
   PORTIONS CENTRAL/WRN DAKOTAS.  AIR MASS OVER THIS REGION IS
   CHARACTERIZED BY MARGINAL BUOYANCY BECAUSE OF STRONG DIURNAL HEATING
   AND RELATIVELY DRY SFC DEW POINTS 40S/50S F. THIS YIELDS MLCAPES
   UNDER 500 J/KG.  SFC-BASED BUOYANCY GOES AWAY IN MODIFIED RAOBS AND
   RUC SOUNDINGS WITH LOSS OF 2-3 DEG C SFC TEMPS.  SHORT-TERM
   POTENTIAL EXISTS FOR HAIL OR DAMAGING DOWNDRAFTS...BUT THREAT IS TOO
   ISOLATED AND TRANSIENT TO WARRANT CATEGORICAL UPGRADE.
   
   ..EDWARDS.. 05/20/2005
   
   ...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 WUUS01 PTSDY1 PRODUCT

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