[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 270550
SWODY2
SPC AC 270549

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1249 AM CDT SUN AUG 27 2006

VALID 281200Z - 291200Z

...NO SVR TSTM AREAS FORECAST...

SUBTROPICAL RIDGING WILL REMAIN PROMINENT ACROSS THE GULF AND SOUTH
ATLANTIC COAST STATES THROUGH THIS FORECAST PERIOD. 
HOWEVER...MODELS SUGGEST AMPLIFICATION WILL OCCUR WITHIN THE POLAR
WESTERLIES...WITH A SIGNIFICANT TROUGH DIGGING ALONG THE BRITISH
COLUMBIA/NORTHERN PACIFIC COAST BY 12Z TUESDAY.  DOWNSTREAM
EVOLUTION IN THE SOUTHERN BRANCH OF SPLIT WESTERLIES REMAINS A BIT
MORE UNCERTAIN...BUT IT APPEARS LIKELY THAT THE CENTRAL STATES
TROUGH WILL MAINTAIN A POSITIVE TILT AND BECOME INCREASINGLY
SHEARED...IN CONFLUENT REGIME BETWEEN SOUTHEASTERN RIDGE AND A
NORTHERN BRANCH TROUGH ACROSS THE EASTERN CANADIAN PROVINCES.

A SURFACE FRONTAL ZONE WILL BE SLOW TO PROGRESS THROUGH THE OHIO
VALLEY MONDAY...BUT SOUTHWARD ADVANCEMENT INTO THE SOUTHERN PLAINS
SHOULD OCCUR.  MONSOONAL MOISTURE ADVECTING AROUND MID-LEVEL RIDGE
WILL CONTRIBUTE TO WIDESPREAD CONVECTIVE DEVELOPMENT ALONG AND SOUTH
OF THIS FRONT...AS THE SOUTHERN BRANCH TROUGH SHIFTS EASTWARD INTO
THE CENTRAL PLAINS.  IN THE WAKE OF UPPER SYSTEM...MOISTURE WILL
REMAIN SUFFICIENT AND INHIBITION WEAK ENOUGH TO ALLOW FAIRLY
WIDESPREAD THUNDERSTORM ACTIVITY ACROSS THE SOUTHERN AND CENTRAL
ROCKIES AS WELL.

...CENTRAL/EASTERN STATES...
SURFACE FRONTAL ZONE IS EXPECTED TO STALL FROM THE NORTHERN MID
ATLANTIC COAST THROUGH THE VICINITY OF THE OHIO RIVER. WHILE THIS
FEATURE...AND WEAK WAVES ALONG IT...WILL PROVIDE THE FOCUS FOR
CONVECTIVE DEVELOPMENT MONDAY...DESTABILIZATION MAY BE LIMITED BY
CONSIDERABLE CLOUD COVER AND MOIST MID-LEVEL ENVIRONMENT WITH WEAK
LAPSE RATES.  WITH FLOW FIELDS/DEEP LAYER SHEAR ASSOCIATED WITH THE
SOUTHERN STREAM LIKELY ONLY MODERATE AT BEST...SEVERE POTENTIAL
SEEMS SMALL.  HOWEVER...HIGH PRECIPITABLE WATER CONTENT AROUND 2
INCHES OR BETTER MAY STILL CONTRIBUTE TO LOCALLY HEAVY
DOWNPOURS...AND PERHAPS A FEW WET DOWNBURSTS.

FARTHER WEST...IT APPEARS THAT A PRE-FRONTAL CONGLOMERATE OUTFLOW
BOUNDARY WILL BECOME THE PRIMARY FOCUS FOR CONVECTIVE DEVELOPMENT BY
MONDAY AFTERNOON...ACROSS CENTRAL ARKANSAS INTO NORTHEAST/NORTH
CENTRAL TEXAS. THIS WILL BE WELL SOUTH OF BETTER MID-LEVEL
FLOW/DEEP LAYER SHEAR...BUT STRONG SURFACE HEATING PROBABLY WILL
CONTRIBUTE TO A HOT DEEP MIXED BOUNDARY LAYER...WHICH SHOULD BE
FAVORABLE FOR LOCALIZED DOWNBURSTS NEAR HEAVIER PRECIPITATION CORES.
 THREAT IS EXPECTED TO DIMINISH EARLY MONDAY EVENING WITH ONSET OF
RADIATIONAL COOLING.

..KERR.. 08/27/2006