[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 281723
SWODY2
SPC AC 281722

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1222 PM CDT WED JUN 28 2006

VALID 291200Z - 301200Z

...THERE IS A SLGT RISK OF SVR TSTMS THU ACROSS PARTS OF THE NRN MID
ATLANTIC COAST STATES....

...THERE IS A SLGT RISK OF SVR TSTMS THU NIGHT ACROSS PARTS OF THE
MID MS VALLEY....

WESTERLIES WILL REMAIN WEAK BENEATH SUBTROPICAL RIDGE ACROSS MUCH OF
THE WESTERN/SOUTHERN STATES THROUGH THIS FORECAST PERIOD.  BUT
...WESTERN RIDGE MAY BEGIN TO WEAKEN SOME...AS A SUBTROPICAL IMPULSE
MIGRATES AROUND ITS NORTHWESTERN/NORTHERN PERIPHERY... ACROSS THE
NORTHERN INTERMOUNTAIN REGION AND NORTHERN ROCKIES. 
DOWNSTREAM...MODELS SUGGEST A SIGNIFICANT IMPULSE...EMBEDDED WITHIN
PERSISTENT TROUGHING OVER THE GREAT LAKES/OHIO VALLEY...WILL
ACCELERATE EASTWARD THROUGH MUCH OF THE NORTHEAST AND MID ATLANTIC
REGION BY 12Z FRIDAY.  THIS IS FORECAST TO OCCUR AS ANOTHER FAIRLY
VIGOROUS SHORT WAVE TROUGH DIGS TO THE SOUTHWEST THROUGH SOUTH OF A
CLOSED LOW OVER SOUTHERN HUDSON/JAMES BAY.

...EAST COAST...
HIGH MOISTURE CONTENT AIR OF THE PAST SEVERAL DAYS IS EXPECTED TO
SHIFT EAST OF ALL BUT THE FLORIDA PENINSULA BY EARLY THURSDAY...AS
IMPULSE EMANATING FROM THE LOWER LATITUDES LIFTS NORTHEAST OF NEW
ENGLAND LATER TODAY.  HOWEVER...LINGERING MOISTURE IS EXPECTED TO BE
SUFFICIENT FOR SCATTERED CONVECTIVE DEVELOPMENT THURSDAY... BENEATH
MID-LEVEL COOL POCKET ASSOCIATED WITH APPROACHING UPPER
TROUGH...FROM THE LOWER LAKES INTO THE NORTHEAST...AND AHEAD OF
UPPER TROUGH AXIS ACROSS THE REMAINDER OF ATLANTIC COASTAL AREAS.

BY THURSDAY AFTERNOON...MODELS SUGGEST STRONGEST FORCING FOR UPPER
VERTICAL MOTION MAY BECOME JUXTAPOSED WITH STRONGEST DESTABILIZATION
ACROSS PARTS OF THE NORTHERN MID ATLANTIC COAST STATES...WHERE ANY
SEVERE THREAT APPEARS MOST LIKELY TO BECOME CONCENTRATED.  MIXED
LAYER CAPE LIKELY WILL EXCEED 1000 J/KG ACROSS THIS REGION...AND
COULD APPROACH 2000 J/KG...WHICH WILL BE SUPPORTIVE OF VIGOROUS
UPDRAFTS.  THOUGH LOW-LEVEL FLOW WILL BECOME RATHER WEAK...30 TO 40+
KT SOUTHERLY MID-LEVEL FLOW AHEAD OF UPPER TROUGH AXIS WILL
CONTRIBUTE TO A MODERATELY SHEARED REGIME WHICH COULD ENHANCE HAIL
POTENTIAL IN STRONGEST STORMS.

...CENTRAL STATES...
WEAK SURFACE FRONT/LOW-LEVEL BAROCLINIC ZONE IS EXPECTED TO STALL
FROM PARTS OF THE TENNESSEE VALLEY THROUGH THE LOWER MISSOURI
VALLEY...AND COULD BECOME FOCUS FOR WIDELY SCATTERED THUNDERSTORMS
LATE THURSDAY AFTERNOON.  LOW-LEVEL THERMAL RIDGE AXIS TO THE SOUTH
OF BOUNDARY WILL CONTRIBUTE TO STEEP LAPSE RATES AND FAVORABLE
THERMODYNAMIC ENVIRONMENT FOR HAIL/GUSTY WINDS IN STRONGER STORMS. 
HOWEVER...POTENTIAL FOR A MORE ORGANIZED OR CONCENTRATED SEVERE
THREAT SEEMS LOW UNTIL AFTER DARK...WHEN NOCTURNAL STRENGTHENING OF
LOW-LEVEL JET..TO THE NORTH OF LOWER MISSISSIPPI VALLEY LOW-LEVEL
RIDGE...COULD SUPPORT A GROWING CLUSTER OF STORMS.  MODELS SUGGEST
THIS IS MOST PROBABLE TO THE COOL SIDE OF THE SURFACE FRONT...ACROSS
PARTS OF SOUTHERN IOWA/ NORTHERN MISSOURI INTO WEST CENTRAL ILLINOIS
BY LATE THURSDAY NIGHT.

...WESTERN STATES...
STRONGEST FORCING ASSOCIATED WITH SUBTROPICAL IMPULSE APPEARS LIKELY
TO SHIFT ACROSS IDAHO THROUGH THE NORTHERN ROCKIES DURING THE
DAYTIME HOURS THURSDAY.  UNCERTAINTY EXISTS CONCERNING EXTENT OF
CLOUD COVER LINGERING FROM DAY 1 CONVECTION...AND ITS INFLUENCE ON
MAGNITUDE OF DAYTIME HEATING.  BUT...EVEN IF CAPE IS MINIMAL...
LARGE LOW-LEVEL TEMPERATURE/DEW POINT SPREADS WILL BE FAVORABLE FOR
AT LEAST LOCALIZED DOWNBURSTS.

..KERR.. 06/28/2006