[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 281639
SWODY1
SPC AC 281638

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1038 AM CST WED DEC 28 2005

VALID 281630Z - 291200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 70 S
MOB 20 WNW GZH 40 N MGM 15 WSW RMG 55 NNW AHN 40 SSE AGS JAX 10 W
OCF 45 WSW PIE.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 70 SW BVE 20 SSW MEI
50 SSW CKV 20 E FAM 10 N STL 20 ESE MMO GRR 30 NNE MTC YNG 20 SSW
SSU 25 NW DAN 40 N AVC 30 SSW NHK 45 ESE DOV ...CONT... 35 E MLB 50
WSW FMY.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 65 NNW UIL 20 W CLM
20 SSE OLM 35 SW YKM 35 WSW PDT 20 NNE BKE 35 SSE MYL 35 SSW SUN 45
WNW ENV 45 SSW TVL 80 SW SFO.

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SOUTHEASTERN
STATES...

...SERN STATES...
VIGOROUS UPPER LOW OVER SRN IL IS EXPECTED TO MOVE EWD ACROSS THE OH
VALLEY AS PROGRESSIVE FLOW REGIME PERSISTS OVER THE CONUS.  THE
SYSTEM IS ASSOCIATED WITH COLD MIDDLE LEVEL TEMPERATURES OF -20C TO
-22C WHICH EXTEND WELL SOUTH INTO THE LOWER MS VALLEY/TN
VALLEY...CONTRIBUTING TO MODERATELY STEEP MIDDLE LEVEL LAPSE RATES
NEAR 7C/KM.  AT THE SURFACE...A LOW NEAR THE IL/IN BORDER IS
FORECAST TO MOVE TOWARD NRN OH.  COLD FRONT ARCING SWD FROM THE LOW
ACROSS MIDDLE TN /MS/SOUTH CENTRAL LA INTO THE GULF WILL MOVE EWD
REACHING ERN PARTS OF KY AND TN/SWRN AL BY 00Z.

PRONOUNCED SWLY LOW LEVEL WINDS AHEAD OF THE COLD FRONT HAVE LIMITED
CONVERGENCE TO SUPPORT CONVECTIVE DEVELOPMENT. WATER VAPOR IMAGERY
ALSO INDICATES STRONG DRYING/SUBSIDENCE IN THE MID/UPPER LEVELS HAS
ADVANCED WELL AHEAD OF THE SURFACE FRONT WHICH IS LIKELY FURTHER
INHIBITING CONVECTIVE STORMS NEAR THE FRONT.  A BAND OF ELEVATED
STORMS HAS DEVELOPED FROM NERN GA INTO EAST CENTRAL AL...APPARENTLY
ALONG THE LEADING EDGE OF STRONG COOLING ALOFT ASSOCIATED WITH THE
UPPER LOW.

LOW LEVEL MOISTURE WITH SURFACE DEW POINTS IN THE UPPER 50S TO LOWER
60S IS EXPECTED TO SPREAD NEWD FROM THE LOWER MS VALLEY/NRN GULF
INTO PARTS OF GA AND NRN FL THIS AFTERNOON.  CONTINUED COOLING ALOFT
WILL AID IN DESTABILIZATION WITH CAPE OF 1000 J/KG EXPECTED ACROSS
SRN PARTS OF AL/GA AND NRN FL. ALTHOUGH FOCUSING MECHANISMS FOR NEW
THUNDERSTORM DEVELOPMENT APPEAR SOMEWHAT UNCERTAIN ATTM...WATER
VAPOR IMAGERY SUGGESTS A ZONE OF ENHANCED LARGE SCALE ASCENT
INITIATING OVER EXTREME SERN LA/SRN MS/SWRN AL REGION...AND VISIBLE
IMAGERY SHOWS A SMALL INCREASE IN SHALLOW CONVECTIVE CLOUDS OVER SRN
AL.  MODEL GUIDANCE INCLUDING THE EXPERIMENTAL WRF-NMM SHOWS AN
INCREASE IN CONVECTION SPREADING ACROSS SERN AL/SRN GA/NWRN FL THIS
AFTERNOON.  GIVEN THE BACKGROUND ENVIRONMENT OF STRONG DEEP LAYER
VERTICAL SHEAR...STORMS WILL HAVE POTENTIAL TO DEVELOP ROTATING
UPDRAFTS WITH STRONGER CELLS CAPABLE OF LARGE HAIL AND DAMAGING WIND
GUSTS. IN ADDITION...LOW LEVEL HODOGRAPH STRUCTURES INDICATE ADDED
POTENTIAL FOR ISOLATED TORNADOES.

...OH VALLEY INTO TN VALLEY...
ALTHOUGH MOISTURE DIMINISHES WITH NWD EXTENT FROM THE GULF
COAST...12Z SOUNDINGS EXHIBITED COLD MID LEVEL TEMPERATURES AND
STEEP LAPSE RATES ABOVE AN INVERSION CENTERED NEAR 850 MB.  THIS
WILL PROVIDE A FAVORABLE THERMODYNAMIC ENVIRONMENT FOR CONTINUED
THUNDERSTORM DEVELOPMENT IN ADVANCE OF THE UPPER LOW NEAR THE
SURFACE FRONT. HAIL AND BRIEF GUSTY WINDS WILL BE POSSIBLE WITH
STRONGER CELLS.

..WEISS.. 12/28/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT WILL BE
DISCONTINUED ON 14 FEBRUARY 2006 BUT WILL REMAIN AVAILABLE
IN THE FOLLOWING PRODUCTS:

   WMO HEADER:       AWIPS ID:
   WUUS01            PTSDY1
   WUUS02            PTSDY2
   WUUS03            PTSDY3

A SERVICE CHANGE NOTICE ...SCN05-39... PROVIDES DETAILS
ON THE TRANSITION. FOR ADDITIONAL DETAILS SEE THE FOLLOWING
WEB ADDRESS USING LOWER CASE LETTERS:
WWW.NWS.NOAA.GOV/OM/NOTIF.HTM