[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 021701
SWODY2
SPC AC 021700

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1200 PM CDT SUN APR 02 2006

VALID 031200Z - 041200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL
APPALACHIANS EWD INTO THE MIDDLE ATLANTIC STATES AND CAROLINAS...

...SYNOPSIS...

MID-LEVEL TROUGH...ANCHORED BY LOW OVER ONTARIO...IS FORECAST TO
BECOME NEGATIVELY-TILTED OVER THE ERN U.S. AS STRONG MID AND
HIGH-LEVEL JET STREAKS DEVELOP SEWD FROM THE MID MS VALLEY INTO THE
CAROLINAS.  IN THE LOW-LEVELS...OCCLUDING SURFACE LOW OVER LOWER MI
WILL DEVELOP NEWD INTO WRN QUEBEC WHILE TRAILING COLD FRONT SURGES
EWD THROUGH THE UPPER OH VALLEY...APPALACHIAN CHAIN INTO THE
ADJACENT COASTAL PLAIN.  MEANWHILE...WARM FRONT WILL SLOWLY LIFT NWD
THROUGH THE MIDDLE ATLANTIC STATES INTO SRN NEW ENGLAND WITH
SECONDARY CYCLOGENESIS OCCURRING AT INTERSECTION OF WARM AND COLD
FRONTS.  THIS SECONDARY SURFACE LOW WILL DEVELOP NEWD FROM NRN VA
INTO SRN NEW ENGLAND BY TUESDAY MORNING.


...CNTRL APPALACHIANS / MIDDLE ATLANTIC COAST SWD INTO THE
CAROLINAS...

A BROKEN BAND OF PRE-FRONTAL CONVECTION IS EXPECTED TO BE ONGOING AT
THE ONSET OF THE FORECAST PERIOD FROM PORTIONS OF THE UPPER OH
VALLEY SWWD ALONG THE SPINE OF THE APPALACHIANS AND INTO NRN
PORTIONS OF MS/AL/GA.  THIS ACTIVITY MAY TEND TO WEAKEN THROUGH THE
DAY AS IT SHIFTS EWD AWAY FROM THE STRONGER FORCING FOR ASCENT AND
INSTABILITY.  IN IT/S WAKE...STRONG HEIGHT FALLS...DAYTIME HEATING
AND LOW-LEVEL MOISTENING FROM THE S AND SW WILL ALL CONTRIBUTE TO
AIR MASS DESTABILIZATION AHEAD DEEP COLD FRONTAL ZONE RAPIDLY
SWEEPING EWD. THIS DESTABILIZATION WILL RESULT IN SBCAPES INCREASING
TO 250-500 J/KG OVER PORTIONS OF PA...TO AS HIGH AS 1000-2000 J/KG
OVER SERN VA INTO THE CNTRL AND ERN CAROLINAS.

A MORE FOCUSED LINE OF VIGOROUS TSTM DEVELOPMENT IS ANTICIPATED BY
EARLY AFTERNOON ALONG FRONT...INITIALLY ALONG NRN PORTION OF
INSTABILITY AXIS OVER ERN OH/WRN PA...WITH SUBSEQUENT SWD
DEVELOPMENT INTO THE CNTRL APPALACHIANS.  WHILE NRN EXTENSION OF
THIS DIURNAL DEVELOPMENT MAY EXHAUST AVAILABLE INSTABILITY OVER
PA/NY BY LATE AFTERNOON...OTHER STORMS MOVING INTO VA AND THE
CAROLINAS SHOULD CONTINUE TO INTENSIFY AS THEY ENCOUNTER
INCREASINGLY UNSTABLE AIR MASS.

IT APPEARS THAT THE MOST CONCENTRATED ZONE OF SEVERE TSTMS WILL
OCCUR ALONG AND S OF SECONDARY SURFACE LOW TRIPLE POINT OVER CNTRL
AND ERN PORTIONS OF VA AND NC PERHAPS INTO SC. HERE...STRONG
VERTICAL SHEAR PROFILES OWING TO PROXIMITY OF MID AND UPPER-LEVEL
JET STREAKS WILL BECOME CO-LOCATED WITH THE MODERATE INSTABILITY. 
WHILE LINE SEGMENTS AND BOWS CAPABLE OF LARGE HAIL AND DAMAGING
WINDS WILL BE THE PRIMARY CONVECTIVE MODE...RELATIVELY STRONG
LOW-LEVEL SHEAR SUGGESTS THE POTENTIAL FOR SUPERCELLS CAPABLE OF
TORNADOES. THESE STORMS SHOULD EVENTUALLY MOVE OFFSHORE BY MID TO
LATE MONDAY EVENING.

FARTHER TO THE SW OVER SC INTO GA...ADDITIONAL MORE ISOLATED TSTMS
WILL BE POSSIBLE DURING THE AFTERNOON AND EVENING HOURS.  MODERATE
INSTABILITY COUPLED WITH MODEST DEEP-LAYER SHEAR SUGGESTS SOME
POTENTIAL FOR ISOLATED DAMAGING WINDS AND HAIL...THOUGH THE WEAKER
LARGE-SCALE FORCING WITH SWD EXTENT SHOULD TEND TO LIMIT THE OVERALL
SEVERE THREAT.

..MEAD.. 04/02/2006