[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 130605
SWODY2
SPC AC 130604

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1204 AM CST MON MAR 13 2006

VALID 141200Z - 151200Z

...NO SVR TSTM AREAS FORECAST...

CONVECTIVE POTENTIAL IS EXPECTED TO DIMINISH CONSIDERABLY BY THE
BEGINNING OF THIS FORECAST PERIOD.  MODELS SUGGEST BROAD UPPER
TROUGH WILL ENCOMPASS MUCH OF THE EASTERN U.S. BY 12Z TUESDAY...
WITH ASSOCIATED DEEP LOW/MID-LEVEL CYCLONE SLOWLY SHIFTING INTO
WESTERN QUEBEC.  AS UPPER TROUGH AXIS DEVELOPS OFF THE ATLANTIC
COAST LATER TUESDAY INTO EARLY WEDNESDAY...MID-LEVEL CYCLONE IS
PROGGED TO CONTINUE EASTWARD INTO THE ST. LAWRENCE VALLEY.  THIS
WILL BE ACCOMPANIED BY SIGNIFICANT SECONDARY SURFACE CYCLOGENESIS
...WHICH MAY COMMENCE AS EARLY AS TUESDAY MORNING OFF THE NORTH
ATLANTIC COAST...BEFORE LIFTING INTO THE CANADIAN MARITIMES.  IN ITS
WAKE... COLD INTRUSION WILL ADVANCE THROUGH THE REMAINDER OF THE
ATLANTIC SEABOARD AND SOUTHEAST STATES.

UPSTREAM...NEXT SIGNIFICANT SHORT WAVE IMPULSE IS FORECAST TO
RAPIDLY PROGRESS INLAND ACROSS THE NORTHERN/CENTRAL CALIFORNIA
COAST...THROUGH MUCH OF THE GREAT BASIN BY 12Z WEDNESDAY.  THIS WILL
BE ACCOMPANIED BY DEVELOPING SURFACE TROUGH IN THE LEE OF THE
CENTRAL/SOUTHERN ROCKIES...AND INCREASING WARM ADVECTION FROM GULF
COASTAL AREAS THROUGH THE SOUTHERN PLAINS BY LATE IN THE PERIOD. 
HOWEVER...MOISTURE RETURN IN THE WAKE OF PRIOR FRONTAL PASSAGE IS
NOT EXPECTED TO BECOME SUFFICIENT FOR CONVECTIVE DEVELOPMENT...
EXCEPT PERHAPS AREAS WEST/SOUTH OF THE LOWER RIO GRANDE VALLEY AND
AREAS  OFF THE LOWER TEXAS COAST.

...ATLANTIC COAST..
SURFACE COLD FRONT APPEARS LIKELY TO ADVANCE INTO NORTHERN MID
ATLANTIC COASTAL AREAS BY AROUND 12Z TUESDAY...AND INTO/ACROSS THE
REMAINDER OF THE ATLANTIC COAST BY MIDDAY.  ANY THUNDERSTORM
ACTIVITY ACROSS NEW ENGLAND IS EXPECTED TO BE BASED ABOVE MARINE
LAYER...AND IN ELEVATED LAYER OF MOIST ISENTROPIC ASCENT TO THE
NORTH/EAST OF DEVELOPING SURFACE LOW.  WITH COLDER AIR ALOFT LAGGING
TO THE WEST OF SURFACE COLD FRONT...CAPE WILL BE LIMITED AND RISK OF
LARGE HAIL SEEMS SMALL.

FARTHER SOUTH...RELATIVELY WARM MID-LEVEL ENVIRONMENT IS ALSO
EXPECTED TO MINIMIZE INSTABILITY AHEAD OF COLD FRONT ACROSS THE
EASTERN CAROLINAS.  WINDOW OF OPPORTUNITY FOR SURFACE HEATING WILL
BE LIMITED WITH FRONT EXPECTED TO ADVANCE OFFSHORE BY/OR SHORTLY
AFTER 15Z TUESDAY...BUT FORCING MAY STILL BE SUFFICIENT TO SUPPORT
NARROW LINE OF CONVECTION BEFORE THIS OCCURS.  THIS COULD ENHANCE
DOWNWARD TRANSFER OF MOMENTUM ASSOCIATED WITH 40-50+ KT MEAN FLOW
REGIME...CONTRIBUTING TO AT LEAST SOME POTENTIAL FOR DAMAGING
SURFACE GUSTS.

...NORTH CENTRAL PACIFIC COAST INTO NORTHERN GREAT BASIN...
STRONG MID-LEVEL COOLING /500 MB COLD CORE BELOW -30C/ IN EXIT
REGION OF MID/UPPER JET STREAK WILL CONTRIBUTE TO DESTABILIZATION AS
IT NOSES INLAND TUESDAY.  THOUGH INSTABILITY SHOULD REMAIN
WEAK...THERMODYNAMIC PROFILES ARE EXPECTED TO BE SUPPORTIVE OF SMALL
HAIL.  BEST POTENTIAL FOR THIS APPROACHING OR BRIEFLY EXCEEDING
SEVERE LIMITS SEEMS TO BE NORTHERN CALIFORNIA COASTAL AREAS INTO THE
SACRAMENTO VALLEY...WHERE LOW-LEVELS WILL BE WARMER AND MORE MOIST. 
THREAT ACROSS THIS REGION IS EXPECTED TO DIMINISH AS ONSHORE
COMPONENT TO LOW-LEVEL FLOW WEAKENS DURING THE MID TO LATE
AFTERNOON.

..KERR.. 03/13/2006