Dec- 6-2004 1630 UTC Day 1 Convective Outlook
Updated: Mon Dec 6 16:33:56 UTC 2004
Categorical Graphic
20041206 1630 UTC Day 1 Outlook Graphic
Probablistic Tornado Graphic
20041206 1630 UTC Day 1 Tornado Probabilities Graphic
Probablistic Damaging Wind Graphic
20041206 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Probablistic Large Hail Graphic
20041206 1630 UTC Day 1 Large Hail Probabilities Graphic
   SPC AC 061629
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1029 AM CST MON DEC 06 2004
   
   VALID 061630Z - 071200Z
   
   THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 NW
   CLL 10 E ACT 10 SSE DAL 25 W PRX 40 N DYR 50 SSE PAH 40 NNE TUP 55 W
   JAN 30 WSW POE 20 NW CLL.
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 SSE
   PSX 45 ENE COT 55 WNW COT 25 NNW DRT 55 W SJT 70 WSW SPS 10 SSW ADM
   35 ENE FSM 30 NNW UNO ALN 20 S DNV 50 NW LUK 45 SW LEX 35 NNE MEI 15
   S 7R4.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 SE ELP 30 ENE ALM
   50 NNW CDS 35 SSE P28 35 ENE MKC 30 SE MLI 10 N SBN TOL 30 NW ZZV 10
   NNE 5I3 10 N SEM 35 SSW MOB ...CONT... 30 SSE CRP 15 SW LRD.
   
   ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FROM
   EAST TX INTO THE MID MS VALLEY...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM TX...ACROSS THE LOWER/MID
   MS VALLEY...INTO THE LOWER OH VALLEY...
   
   POWERFUL UPPER TROUGH OVER SOUTHERN NM IS FORECAST TO TRACK RAPIDLY
   EASTWARD ACROSS TX AND INTO THE MID MS VALLEY THIS AFTERNOON AND
   TONIGHT.  12Z ETA GUIDANCE SUGGESTS TROUGH IS STRONGER AND HIGHER
   AMPLITUDE THAN PREVIOUS RUNS...INCREASING CONFIDENCE OF A HEIGHTENED
   THREAT OF SEVERE STORMS FROM TX INTO THE LOWER OH VALLEY.
   
   ...WEST/CENTRAL TX TODAY...
   SCATTERED THUNDERSTORMS HAVE DEVELOPED THIS MORNING NEAR MAF.  THIS
   ACTIVITY IS BENEATH LEADING EDGE OF STRONG UPPER FORCING...AND
   SHOULD SPREAD EASTWARD INTO NORTH CENTRAL TX BY THIS AFTERNOON. 
   SUFFICIENT ELEVATED CAPE IN THIS AREA COULD POSE A RISK OF LARGE
   HAIL IN STRONGER CELLS.  STEEP LAPSE RATES ON NOSE OF MID LEVEL DRY
   SLOT MAY ALSO ALLOW STRONGER GUSTS TO REACH THE SURFACE.
   
   ...EAST TX...NRN LA...SRN AR...WEST TN...NWRN MS...
   WIDESPREAD THUNDERSTORMS ARE EXPECTED TO INCREASE THIS AFTERNOON
   ACROSS CENTRAL TX...AS STRONGER VERTICAL MOTION FIELD OVERSPREADS
   LOW LEVEL MOISTURE/INSTABILITY.  SURFACE DEWPOINTS IN THE UPPER 60S
   AND COMBINATION OF HEIGHT FALLS/COOLING AT MID LEVELS WILL HELP
   DESTABILIZE THIS AREA WITH MUCAPE VALUES OF 1000-1500 J/KG.  STORMS
   IN THIS AREA WILL ALSO BE IN AN INCREASINGLY FAVORABLE VERTICAL
   SHEAR PROFILE AS LOW LEVEL JET STRENGTHENS...WITH SUPERCELLS AND A
   FEW TORNADOES POSSIBLE BY LATE AFTERNOON AND EARLY EVENING. 
   SUPERCELL STORMS ARE EXPECTED TO TRACK/DEVELOP RAPIDLY NORTHEASTWARD
   OVERNIGHT ACROSS SRN AR/NRN LA AND INTO PARTS OF TN/MS.  ORGANIZED
   SQUALL LINE WILL ALSO LIKELY RACE THROUGH THIS AREA WITH THE MAIN
   COLD FRONT...WITH THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS. 
   PRIMARY MITIGATING FACTOR FOR A MAJOR SEVERE WEATHER EPISODE IS THE
   LACK OF STRONG INSTABILITY.  HOWEVER...STRENGTH OF WIND FIELDS AND
   RAPIDLY DEEPENING SURFACE LOW SUGGEST THAT DYNAMICS MAY BE STRONG
   ENOUGH TO PARTIALLY COMPENSATE FOR WEAK CAPE VALUES.
   
   ...MID MS AND LOWER OH VALLEYS LATE TONIGHT...
   MODEL GUIDANCE SUGGESTS THAT SURFACE LOW WILL DEEPEN RAPIDLY OVER
   MO/IL LATE TONIGHT.  VERY STRONG SOUTHERLY LOW LEVEL WINDS AHEAD OF
   LOW MAY TRANSPORT SUFFICIENT MOISTURE INTO REGION FOR SURFACE-BASED
   THUNDERSTORMS. FOCUSED ASCENT IN VICINITY OF LOW AND TRAILING COLD
   FRONT MAY RESULT IN A NARROW LINE OF STORMS CAPABLE OF DAMAGING
   WINDS ACROSS SERN MO/SRN IL/SERN IND...MAINLY AFTER 06Z.
   
   ..HART.. 12/06/2004
   
   ...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 BY 2000Z