[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 021620
SWODY1
SPC AC 021618

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1118 AM CDT WED AUG 02 2006

VALID 021630Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL PLAINS THRU
THE MIDDLE MS VALLEY AND GREAT LAKES TO NEW ENGLAND...

...SYNOPSIS...
WESTERLIES NOW PREVAIL FROM COAST TO COAST ACROSS NRN TIER OF CONUS
WITH BROAD HIGH PRESSURE DOMINATING MUCH OF SRN U.S.  BAND OF
40-50KT MID LEVEL WESTERLIES IN ADVANCE OF S/WV TROUGH NOW MOVING
ACROSS NRN CENTRAL U.S. WILL TRANSLATE EWD ACROSS GREAT LAKES THIS
AFTERNOON AND NERN U.S. TONIGHT.

COLD FRONT FROM UPR MI EXTENDS SWWD THRU SERN NEB TO NERN NM.  FRONT
WILL CONTINUE EWD ACROSS GREAT LAKES AND BY LATER TONIGHT REACH FROM
NRN NY BACK TO VICINITY OK/KS BORDER.

WARM...MOIST AND POTENTIALLY VERY UNSTABLE AIR REMAINS S AND E OF
FRONTAL ZONE PARTICULARLY MS VALLEY EWD.

...GREAT LAKES TO NERN U.S...
STRONG HEATING MOST AREAS TO S OF COLD FRONT WHERE DEWPOINTS
GENERALLY 70F OR GREATER WILL GENERATE A VERY UNSTABLE AIR MASS WITH
MLCAPES RANGING UPWARDS TO 2500 J/KG MANY AREAS.

PRIMARY FOCUS FOR SEVERE THUNDERSTORM INITIATION THIS AFTERNOON WILL
BE THE FRONTAL CONVERGENCE.  BY MID AFTERNOON SEVERE THUNDERSTORMS
EXPECTED TO BE INCREASING IN NUMBER AND INTENSITY FROM WI EWD ACROSS
LOWER MI THRU UPSTATE NY AND WRN NEW ENGLAND.  WITH 30-40KT OF DEEP
LAYER SHEAR...STORMS SHOULD EVOLVE INTO SHORT LINES/BOW IN THE
STRONG FLOW WITH ACCOMPANYING WIND DAMAGE POTENTIAL.  LARGE HAIL
THREAT WILL BE SOMEWHAT MITIGATED BY THE WARM LAPSE RATES.
SUFFICIENT SHEAR GIVEN LARGE AMOUNT OF INSTABILITY FOR SUPERCELL
POTENTIAL. THIS WOULD RESULT IN AN ENHANCED SEVERE THREAT ALONG WITH
ISOLATED TORNADOES.

ONE OF MORE FORWARD PROPAGATING MCS'S LIKELY DEVELOPING THIS EVENING
WHICH ALSO WOULD INCREASE WIND DAMAGE THREAT.

...MID MS VALLEY SWWD TO CENTRAL/SRN HIGH PLAINS...
DEEP LAYER SHEAR WILL RANGE DOWNWARD ALONG FRONTAL ZONE FROM 25-30KT
IA AREA TO LESS THAN 20KT HIGH PLAINS.

HOWEVER THE STRONG HEATING WILL DEVELOP STEEP LOW/MID LAPSE RATES
AHEAD OF FRONT ALONG WITH MLCAPES CLIMBING TO AS HIGH AS 2000 J/KG.
THUNDERSTORMS WILL ALSO DEVELOP IN RESPONSE TO FRONTAL CONVERGENCE
BY MID/LATE AFTERNOON. CONVECTIVE MODE SHOULD BE MORE MULTI-CELLULAR
WITH ISOLATED SUPERCELLS POSSIBLE.  DAMAGING WINDS AND LARGE HAIL
WOULD BE LIKELY...PARTICULARLY IN KS PORTION WHERE CAPE/SHEAR
COMBINATION APPEARS TO BE MORE FAVORABLE.

..HALES/CROSBIE.. 08/02/2006