[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 031730
SWODY2
SPC AC 031729

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1229 PM CDT THU AUG 03 2006

VALID 041200Z - 051200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
LARGE SCALE RIDGE WILL SPREAD ACROSS THE SRN TWO-THIRDS OF THE U.S.
DURING THE PERIOD.  THIS WILL KEEP MAIN BAND OF WESTERLIES ACROSS
SRN CANADA/NRN TIER OF STATES. ONE MINOR SHORTWAVE TROUGH WILL MOVE
EWD ACROSS THE NRN GREAT LAKES DURING THE SECOND HALF OF THE
PERIOD...WHILE SECOND STRONGER TROUGH/ASSOCIATED VORTICITY MAX MOVES
SEWD ACROSS ALBERTA/SASKATCHEWAN.  COLD FRONTAL BOUNDARY MOVING
SWD/SEWD ACROSS THE LOWER GREAT LAKES AND NRN MID ATLANTIC REGION ON
DAY 1 WILL WEAKEN UNDERNEATH DOMINATE RIDGE AS IT MOVES THRU VA AND
KY.

...NRN PLAINS...

NAM MODEL RATHER AGGRESSIVE COMPARED TO THE GFS OVER PARTS OF ERN ND
INTO NRN MN.  THIS IS IN ASSOCIATION WITH STRONG WARM ADVECTION
ASSOCIATED WITH EXIT REGION OF 35-45 KT LOW LEVEL JET THAT EXTENDS
FROM NEB INTO CENTRAL AND NERN MN.  THE NAM GENERATES QUITE A BIT OF
DEEP LAYER SHEAR ACROSS MN S OF A WEAK FRONT THAT MAKES ITS WAY SWD
THRU THIS REGION FRIDAY NIGHT. BUT...MODEL SOUNDINGS INDICATE VERY
STRONG CAPPING INVERSION THRU THE NRN PLAINS WHICH WILL INHIBIT
CONVECTIVE DEVELOPMENT EXCEPT NEAR THE ND/CANADA BORDER WHERE 50 KT
MID LEVEL FLOW IS FORECAST...THEN ESEWD ACROSS EXTREME NRN MN. SOME
THUNDERSTORMS CAN MOVE EWD/SEWD ACROSS EXTREME NRN MN FRIDAY
NIGHT...BUT GIVEN THE LIMITED EFFECTIVE INSTABILITY AND ELEVATED
NATURE OF THE STORMS...WOULD EXPECT ACTIVITY TO MOSTLY BE BELOW
SEVERE LEVELS.

...PARTS OF ERN VA/ERN NC...

REMNANTS OF COLD FRONTAL BOUNDARY IS EXPECTED TO EXTEND FROM THE
CENTRAL DELMARVA INTO THE TN VALLEY FRI AFTN.  AIR MASS ALONG AND S
OF THE BOUNDARY WILL BE MODERATELY UNSTABLE WITH SBCAPES FORECAST
BETWEEN 2000 AND 3000 J/KG.  SCATTERED THUNDERSTORMS ARE EXPECTED IN
THE VICINITY OF THE BOUNDARY...BUT REMAIN BELOW SEVERE LEVELS DUE TO
WEAK FLOW AND HIGHER GEOPOTENTIAL HEIGHTS FROM DOMINATING RIDGE. 
ACTIVITY COULD PRODUCE SOME STRONG WINDS GIVEN THE EXPECTED 20 DEG
T/TD SPREADS...BUT GIVEN WEAK FLOW ALOFT AND LOW/MID LEVEL LAPSE
RATES AROUND 6-6.5C/KM ACTIVITY SHOULD REMAIN BELOW SEVERE LEVELS.

..MCCARTHY.. 08/03/2006