[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 130556
SWODY1
SPC AC 130555

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1255 AM CDT WED SEP 13 2006

VALID 131200Z - 141200Z

...NO SVR TSTM AREAS FORECAST...

...UPPER OH/TN VALLEYS SWD TO GULF COAST...
UPPER TROUGH CENTERED OVER THE MID MS/LOWER OH VALLEYS AT 12Z WILL
TRACK NORTHEAST TOWARD THE LOWER GREAT LAKES REGION THIS FORECAST
PERIOD...WITH STRONGEST UPPER FORCING SPREADING ACROSS THE UPPER OH/
TN VALLEYS.  ATTENDANT COLD FRONT WILL MOVE SLOWLY EWD TODAY THROUGH
THE OH/TN VALLEYS AND NRN GULF COAST.  A NARROW AXIS OF MOISTURE
WILL EXTEND NWD IN ADVANCE OF THE COLD FRONT...WITH HIGHEST SURFACE
DEWPOINTS EXPECTED TO BE CONFINED TO THE GULF COAST STATES.  WEAK
MID LEVEL LAPSE RATES AND EXTENSIVE CLOUD COVER ARE EXPECTED TO
RESULT IN WEAK INSTABILITY...GENERALLY BELOW 1000 J/KG...MINIMIZING
THE OVERALL SEVERE THREAT.  IF SURFACE HEATING TAKES PLACE IN
ADVANCE OF THE COLD FRONT...THEN POCKETS OF GREATER INSTABILITY WILL
BE POSSIBLE.

LOW LEVEL CONVERGENCE IS EXPECTED TO BE WEAK ALONG THE FRONT...BUT
THE COMBINATION OF FRONTAL LIFT AND ASCENT AHEAD OF THE SHORT WAVE
TROUGH SHOULD SUPPORT THUNDERSTORM DEVELOPMENT ALONG THE
PROGRESSIVE...YET SLOW MOVING COLD FRONT.  ALTHOUGH DEEP LAYER SHEAR
WILL BE FAVORABLE FOR STORM ORGANIZATION...GENERALLY WEAK
INSTABILITY WILL LIMIT DEVELOPMENT OF SEVERE STORMS.  FARTHER S...
WEAK UPPER FORCING SHOULD RESULT IN LESS STORM DEVELOPMENT...THOUGH
AVAILABLE WEAK INSTABILITY AND 30-35 KT OF DEEP LAYER SHEAR MAY
SUPPORT A FEW STRONG TO SEVERE STORMS

...AZ/SWRN NM...
UPPER LOW LOCATED OVER NRN BAJA/SWRN AZ WILL MOVE EWD TODAY REACHING
WRN NM BY 12Z THURSDAY.  EXTENSIVE CLOUD COVER CURRENTLY LOCATED
ACROSS MUCH OF AZ INTO SWRN NM MAY RESULT IN LIMITED SURFACE HEATING
AND LACK OF GREATER DESTABILIZATION THIS FORECAST PERIOD.  LARGE
SCALE ASCENT AHEAD OF THE UPPER LOW COMBINED WITH STEEP MID LEVEL
LAPSE RATES AND SUFFICIENT LOW LEVEL MOISTURE WILL ALLOW FOR
THUNDERSTORMS ACROSS CENTRAL/SRN AZ INTO SWRN NM.  HOWEVER...THE
THREAT FOR SEVERE STORMS SHOULD BE MINIMAL...GIVEN THE POTENTIAL FOR
WEAK INSTABILITY.

..PETERS/CROSBIE.. 09/13/2006