[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 230545
SWODY2
SPC AC 230544

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1144 PM CST THU DEC 22 2005

VALID 241200Z - 251200Z

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 SE BPT 30 ENE IER
25 NE LLQ 25 SW MEM 30 SE MKL 50 NNE HSV 55 SSW TYS 35 NW AND 25 E
SPA 35 WSW SOP 30 NNE FAY 20 WNW EWN 20 SSE EWN 85 SE EWN ...CONT...
40 ENE VRB 50 WSW APF.

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

A HIGH-AMPLITUDE PATTERN IS FORECAST THROUGH THE DAY TWO PERIOD WITH
PRIMARY FEATURE OF INTEREST BEING EVOLUTION OF DEEP MID/UPPER-LEVEL
TROUGH OVER THE ERN HALF OF THE NATION.  SHORTWAVE TROUGH OVER THE
PACIFIC NW AS OF 23/12Z WILL UNDERGO SIGNIFICANT AMPLIFICATION OVER
THE NEXT 36 HOURS AS IT PROGRESSES SEWD...DUE IN LARGE PART TO
REINTENSIFICATION OF WRN U.S. RIDGE.

IN THE LOW-LEVELS...PRIMARY SURFACE LOW ASSOCIATED WITH EVOLVING
UPPER TROUGH IS EXPECTED TO BE OVER THE MID MS VALLEY AT 24/12Z. 
DESPITE SOME MODEL DIFFERENCES IN IT/S TRACK...THIS FEATURE WILL
GENERALLY DEVELOP NEWD INTO THE UPPER OH VALLEY OR CNTRL/ERN GREAT
LAKES BY 25/12Z.  MEANWHILE...TRAILING COLD FRONT WILL PUSH EWD
THROUGH THE LOWER MS VALLEY AND GULF COAST AND WILL LIKELY EXTEND
FROM THE SURFACE LOW SWD ACROSS THE PIEDMONT INTO NRN FL BY SUNDAY
MORNING.


...GULF COAST INTO THE SERN STATES...

CURRENT SURFACE OBSERVATIONS AND GPS PW LOOPS INDICATE A RELATIVELY
DRY AIR MASS /DEWPOINTS IN THE UPPER 30S TO LOWER 40S/ ACROSS THE
NRN GULF OF MEXICO WITH THE RICHEST MOISTURE CONFINED TO THE SRN BAY
OF CAMPECHE.  INCREASING SLY LOW-LEVEL WINDS AHEAD OF UPPER TROUGH 
AND SURFACE COLD FRONT WILL ALLOW FOR THE NWD RETURN OF A MODIFIED
GULF AIR MASS...WITH DEWPOINTS INCREASING THROUGH THE 50S FROM THE
COAST INLAND.  DESPITE CONSIDERABLE COOLING ALOFT...IT APPEARS THAT
THE MARGINAL MOISTURE RETURN AND MODEST LAPSE RATES WILL TEND TO
LIMIT INSTABILITY WITH MLCAPES AOB 500 J/KG.

ELEVATED TSTMS ARE EXPECTED TO BE IN PROGRESS OR DEVELOPING AT THE
ONSET OF THE FORECAST PERIOD OVER PARTS OF THE LOWER MS VALLEY AS
STRONGER DEEP-LAYER FORCING BEGINS OVERSPREADING WRN EDGE OF
RETURNING LOW-LEVEL MOISTURE.  STORMS ARE EXPECTED TO BECOME
PROGRESSIVELY MORE SURFACE-BASED BY LATE MORNING OR EARLY AFTERNOON
OWING TO BOUNDARY-LAYER HEATING AND RESULTANT DESTABILIZATION. 
THESE STORMS WILL THEN MOVE/DEVELOP EWD ACROSS ERN LA...MS AND AL
SATURDAY AND INTO FL...GA AND SC SATURDAY NIGHT.

DESPITE INCREASING VERTICAL SHEAR AND LARGE-SCALE FORCING FOR
ASCENT...IT APPEARS THAT THE MARGINAL INSTABILITY WILL BE THE
PRIMARY FACTOR LIMITING THE SEVERE WEATHER THREAT ACROSS THE
DISCUSSION AREA.  NONETHELESS...POTENTIAL WILL EXIST FOR SOME
EMBEDDED BOWING OR LEWP STRUCTURES CAPABLE OF ISOLATED DAMAGING
WINDS AND PERHAPS A TORNADO OR TWO.  SHOULD OBSERVATIONAL DATA
AND/OR LATER NWP GUIDANCE INDICATE THAT INSTABILITY WILL BE STRONGER
THAN IS CURRENTLY ANTICIPATED...AN UPGRADE TO SLIGHT RISK MAY BE
REQUIRED IN SUBSEQUENT DAY ONE OUTLOOKS.

..MEAD.. 12/23/2005

...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