[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 030531
SWODY1
SPC AC 030530

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1130 PM CST FRI DEC 02 2005

VALID 031200Z - 041200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 SSE
BHM 15 ENE JAN 35 NNE ESF 40 SSW ELD 30 NNW ELD PBF MKL 30 W BNA 30
NW CSV 25 SE CSV 45 ENE RMG 30 NNW ATL 20 SSE BHM.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 E ORF 45 NE EWN 20
ESE FLO 15 SSW AGS 45 SE ESF 10 S HOU 55 NNE VCT 35 E AUS 25 E TPL
10 NNW TXK 30 NNE DYR 35 S LUK 20 SSE PKB 20 W MRB 40 ESE ACY.

...THERE IS A SLGT RISK OF SVR TSTMS OVER THE LOWER MS VALLEY AND TN
VALLEY...

...SYNOPSIS...
BROAD UPPER TROUGH OVER THE NWRN STATES IS FORECAST TO MOVE EWD
ACROSS THE NRN PLAINS TOWARD THE UPPER MS VALLEY TODAY.  THIS WILL
OCCUR AS A STRONG MID/UPPER LEVEL JET STREAK PROGRESSES ACROSS THE
CENTRAL PLAINS DURING THE DAY AND REACHES THE MIDDLE MS VALLEY
TONIGHT.  AT THE SURFACE...A LOW CURRENTLY OVER SERN CO IS EXPECTED
TO DEVELOP SEWD INTO SRN OK EARLY IN THE PERIOD ALONG AN EAST/WEST
AXIS OF WARM FRONTOGENESIS THAT IS NOW DEVELOPING EWD INTO AR. THE
LOW IS FORECAST TO MOVE EWD TOWARD WRN TN BY 00Z...THEN CONTINUE
ENEWD TOWARD WV BY THE END OF THE PERIOD.  A COLD FRONT EXTENDING
SWWD FROM THE LOW WILL MOVE SEWD THROUGH THE NIGHT...REACHING AN ERN
TN/CENTRAL MS/SOUTH CENTRAL TX LINE BY 04/12Z.

...TN VALLEY INTO THE LOWER MS VALLEY...
CURRENT PROFILER/VAD WIND DATA INDICATE THE LOW LEVEL JET HAS
DEVELOPED AND INTENSIFIED FROM ERN TX INTO AR WITH 50 KT SWLY WINDS
AT 1 KM AGL AT PAT.  GOES SOUNDER AND GPS WATER VAPOR DATA CONFIRM
THE NNEWD RETURN OF MOISTURE FROM THE NWRN GULF ACROSS ERN TX/WRN LA
INTO SWRN AR.  THE VERTICALLY INTEGRATED MOISTURE FIELD EXTENDS
DOWNSTREAM FROM THE REGION OF HIGHER SURFACE DEW POINTS OVER ERN
TX...CONSISTENT WITH MODEL FORECASTS OF ELEVATED MOISTURE SPREADING
TOWARD THE MID SOUTH REGION BY SUNRISE.

MARGINAL ELEVATED INSTABILITY ON THE NOSE OF THE LOW LEVEL JET MAY
SUPPORT SCATTERED WEAK CONVECTION INCLUDING ISOLATED THUNDERSTORMS
EARLY IN THE PERIOD FROM ERN AR INTO WRN TN AND NRN PARTS OF MS AND
AL.  THE THUNDERSTORM ACTIVITY IS EXPECTED TO GRADUALLY DEVELOP
EWD/NEWD ACROSS TN AND KY DURING THE DAY AND INCREASE IN COVERAGE AS
ADDITIONAL MOISTURE ADVECTS INTO PARTS OF THE TN VALLEY.  THE
ELEVATED NATURE OF STORMS AND WEAK INSTABILITY SHOULD LIMIT THE
SEVERE POTENTIAL ALTHOUGH STRONG VERTICAL SHEAR MAY AID STORM
ORGANIZATION WITH ISOLATED STRONG STORMS POSSIBLE.

MORE SIGNIFICANT STORMS ARE EXPECTED TO DEVELOP DURING THE LATE
AFTERNOON AND EVENING IN ADVANCE OF THE SURFACE LOW AS IT MOVES
ACROSS ERN AR AND WRN TN.  BY THIS TIME...LOW LEVEL MOISTURE WILL
HAVE INCREASED ACROSS THE LOWER MS VALLEY WITH SURFACE DEW POINTS IN
THE UPPER 50S/LOWER 60S INTO NRN MS/AL AND POSSIBLY SRN TN.  IN
ADDITION...A PLUME OF STEEPER MID LEVEL LAPSE RATES ASSOCIATED WITH
THE STRONG WSWLY MID LEVEL FLOW IS FORECAST TO SPREAD EWD ACROSS THE
LOWER MS VALLEY TOWARD THE TN VALLEY.  WHILE THIS ELEVATED MIXED
LAYER SHOULD INITIALLY INHIBIT CONVECTION IN THE WARM SECTOR THROUGH
MID AFTERNOON...INCREASING LOW LEVEL CONVERGENCE NEAR THE LOW AND
WARM FRONT SUGGESTS CONVECTIVE POTENTIAL WILL INCREASE FROM PARTS OF
ERN AR INTO WRN/MIDDLE TN AND NRN MS/NRN AL BY LATE AFTERNOON OR
EVENING.  DEEP LAYER SHEAR OF 40-50 KT IN THE LOWEST 6 KM AND VERY
STRONG LOW LEVEL SHEAR/HELICITY IN THE LOWEST 1-2 KM INDICATE
POTENTIAL FOR SUPERCELLS TO DEVELOP.  DAMAGING WINDS AND LARGE HAIL
ARE EXPECTED TO BE THE PRIMARY THREATS...BUT A FEW TORNADIC
SUPERCELLS ARE ALSO POSSIBLE.

THE STRONGEST LOW LEVEL JET IS FORECAST TO MOVE RAPIDLY NEWD INTO
ERN PARTS OF TN AND KY TONIGHT...MOVING AWAY FROM THE REGION OF
GREATER MOISTURE/INSTABILITY REMAINING OVER LA/MS AND AL.  THUS...
STORMS MOVING TOWARD THE APPALACHIANS WILL LIKELY BECOME
INCREASINGLY ELEVATED AND GRADUALLY WEAKEN AS THEY MOVE INTO A 
MARGINALLY UNSTABLE ENVIRONMENT.  FARTHER WEST...MODEL GUIDANCE
INDICATES A NEW LINE OF STORMS WILL BACKBUILD AT NIGHT FROM SRN
TN/NRN AL/NRN MS WSWWD INTO PARTS OF SERN AR AND PSBLY NRN LA AS THE
COLD FRONT MOVES INTO THE LOW LEVEL MOISTURE/INSTABILITY FIELD. 
STRONG VERTICAL SHEAR SUGGESTS POTENTIAL FOR A FEW STRONG/SEVERE
STORMS TO PERSIST INTO THE OVERNIGHT HOURS... ESPECIALLY IF BOWING
SEGMENTS WITH A COMPONENT NORMAL TO THE LINE CAN DEVELOP.

..WEISS.. 12/03/2005

...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