[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 201722
SWODY2
SPC AC 201721

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1121 AM CST WED DEC 20 2006

VALID 211200Z - 221200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
12Z GFS/NAM HAVE COME INTO BETTER AGREEMENT WITH THE TEMPORAL
RESOLUTION OF THE UPPER LOW AS IT TRACKS FROM SW KS AND TX PANHANDLE
REGION NEWD TO THE EAST CENTRAL PLAINS/MID-LOWER MO VALLEY BY
22/12Z.  THIS TRANSLATES TO THE SURFACE WITH MORE CONSISTENCY IN THE
SPEED OF THE COLD FRONT AS IT SHOULD SPREAD SLOWLY EWD ACROSS THE
MID AND LOWER MS VALLEY.

...LOWER MS VALLEY...
DESPITE MOISTURE SPREADING NWD AHEAD OF THE COLD FRONT WITH SURFACE
DEWPOINTS IN THE MID 60S REACHING PARTS OF NERN LA AND CENTRAL MS...
EXTENSIVE CLOUDINESS SHOULD CONTINUE TO LIMIT THE POTENTIAL FOR
SURFACE HEATING...AND THE DEVELOPMENT OF STRONGER INSTABILITY.  THIS
COMBINED WITH GENERALLY WEAK LAPSE RATES IS EXPECTED TO RESULT IN
MARGINAL INSTABILITY.  UPPER FORCING SHOULD REMAIN WEAK ACROSS THE
LOWER MS VALLEY ON DAY 2...GIVEN SMALL HEIGHT FALLS LOCATED TO THE S
OF THE TRACK OF THE UPPER LOW.  SOME ASCENT SHOULD OCCUR AS WEAK SRN
STREAM IMPULSES TRAVERSE GULF COAST PORTION OF LOWER MS VALLEY.

NONETHELESS...WEAK UPPER FORCING COMBINED WITH FRONTAL ASCENT AND
AMPLE LOW/MID LEVEL MOISTURE WILL SUPPORT CONTINUATION OF SHOWERS
WITH EMBEDDED TSTMS FROM THE NWRN GULF COAST REGION NWD TO THE MID
MS/LOWER OH VALLEYS.  STRENGTH OF WIND FIELDS WITH SUFFICIENT DEEP
LAYER SHEAR SUGGEST POTENTIAL FOR ISOLATED THUNDERSTORM
INTENSIFICATION AND A MARGINAL SEVERE THREAT THROUGH THE FORECAST
PERIOD.  FORECAST SOUNDINGS INDICATE LOW LEVEL HODOGRAPH CURVATURE
MAY SUPPORT AN ISOLATED TORNADO THREAT...IN ADDITION TO DAMAGING
WINDS WITH THE STRONGER ACTIVITY.  WEAK INSTABILITY AND UNCERTAINTY
IN POTENTIAL COVERAGE OF SEVERE THREAT WILL MAINTAIN LOW SEVERE
PROBABILITIES WITH THIS OUTLOOK.

..PETERS.. 12/20/2006