Sep-17-2004 2000 UTC Day 1 Convective Outlook
Updated: Fri Sep 17 20:01:50 UTC 2004
Categorical Graphic
20040917 2000 UTC Day 1 Outlook Graphic
Probablistic Tornado Graphic
20040917 2000 UTC Day 1 Tornado Probabilities Graphic
Probablistic Damaging Wind Graphic
20040917 2000 UTC Day 1 Damaging Wind Probabilities Graphic
Probablistic Large Hail Graphic
20040917 2000 UTC Day 1 Large Hail Probabilities Graphic
   SPC AC 171953
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0253 PM CDT FRI SEP 17 2004
   
   VALID 172000Z - 181200Z
   
   THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 WNW
   ILM 30 NE FLO RDU 15 NE DAN 25 WNW SHD 50 NNE SHD 30 SSE MRB 15 NW
   NHK 45 S NHK ORF EWN 25 WNW ILM.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 SSW
   CRE 30 N CHS 20 NNW FLO 40 ESE CLT 15 NW PSK 10 NW EKN 25 S AOO 35 E
   CXY 10 ESE ACY.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 WNW CTY AYS 45 SE
   AGS 40 SSE SPA 20 ENE TYS 40 WNW HTS 25 WNW PIT 30 SE UCA 10 SE PWM.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 55 ENE CTB 30 NNE SUN
   75 NNW LOL 10 SW EKA.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 80 WSW TUS 50 ENE PHX
   35 NNW SOW 35 ESE ONM 40 SSE LVS 20 WSW RTN 20 SSE LHX 30 NNW RSL 40
   N GRI FSD 25 N FRM 30 S RST 25 N COU 10 ENE UMN 20 SSW BVO P28 40 S
   EHA 35 ESE CVS 20 S INK 75 S MRF.
   
   ...THERE IS A MDT RISK OF SVR TSTMS ACROSS ERN VA...MUCH OF ERN
   NC...AND PARTS OF SRN MD...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM SRN PA / SRN NJ / ERN WV
   SWD INTO NERN NC...
   
   ...MID-ATLANTIC REGION...
   STRONG LOW- TO MID-LEVEL WIND FIELD PERSISTS ACROSS THE MID-ATLANTIC
   REGION THIS AFTERNOON IN ERN HALF OF CIRCULATION ASSOCIATED WITH THE
   REMNANTS OF IVAN.
   
   BROKEN N-S LINE OF STORMS EXISTS FROM ERN SC NWD ACROSS CENTRAL NC
   INTO CENTRAL VA...WHILE MORE ISOLATED CONVECTION IS ONGOING AHEAD OF
   THIS LINE.  WITH BACKED SURFACE WIND FIELD ALONG AND E OF THIS
   CONVECTIVE LINE BENEATH STRONG / WEAKLY-VEERING FLOW THROUGH 700
   MB...SHEAR PROFILES REMAIN FAVORABLE FOR ROTATING STORMS.
   
   ALTHOUGH MID-LEVEL LAPSE RATES REMAIN WEAK ACROSS THIS
   REGION...DAYTIME HEATING OF VERY MOIST BOUNDARY LAYER HAS ALLOWED
   STEEP LOW-LEVEL LAPSE RATES TO DEVELOP ALONG WITH 500 TO 1500 J/KG
   MEAN-LAYER CAPE.  THIS COMBINED WITH STRONGLY-SHEARED LOW-LEVEL
   ENVIRONMENT HAS RESULTED IN A FAVORABLE ENVIRONMENT FOR SUPERCELLS
   AND TORNADOES.
   
   ALTHOUGH LOW-LEVEL STABILIZATION WITH THE LOSS OF DAYTIME HEATING
   SUGGESTS A SLOW DECREASE IN TORNADO POTENTIAL LATER THIS EVENING /
   OVERNIGHT...ENHANCED THREAT WILL PERSIST FOR SEVERAL HOURS -- LIKELY
   WELL INTO THIS EVENING.
   
   ...MIDDLE MO VALLEY REGION...
   ELEVATED THUNDERSTORMS CONTINUE ATTM ACROSS PARTS OF ERN KS AS WELL
   AS WRN PORTIONS OF MO...IN ZONE OF WEAK WARM ADVECTION.  A FEW
   STORMS WILL LIKELY LINGER THROUGH THE AFTERNOON AND INTO THE
   EVENING...WHEN AN INCREASE IN CONVECTION MAY OCCUR AS LOW-LEVEL JET
   NOCTURNALLY RE-INTENSIFIES.  ALTHOUGH STORMS WILL REMAIN
   ELEVATED...SUFFICIENT INSTABILITY ABOVE APPROXIMATELY 800 MB MAY
   SUPPORT A FEW MARGINALLY-SEVERE HAIL EVENTS WITH STRONGER STORMS
   THROUGH THE END OF THE PERIOD.
   
   ..GOSS.. 09/17/2004
   
   ...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