[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 221722
SWODY2
SPC AC 221721

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1221 PM CDT FRI APR 22 2005

VALID 231200Z - 241200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 SSE
CEW MAI 55 ESE MCN CAE DAN 10 NE AOO 35 ENE BFD BGM 15 S PHL 15 SSW
ACY ...CONT... VRB AGR 40 NW AGR 15 SSE PIE.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 N PBG 10 S EFK LCI
15 E HYA ...CONT... PNS MCN AHN 10 W AVL UNI 20 NE CLE.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM CZZ RAL 40 N SBA MER
30 E ACV 25 E AST CLM 20 SE BLI 40 SSE 4OM HLN 10 SSE JAC 10 N RKS
10 N ASE 4SL ONM GDP 60 SSW P07.

...THERE IS A SLGT RISK OF SVR TSTMS SATURDAY ACROSS THE MID
ATLANTIC COAST STATES...AND PARTS OF NRN/CENTAL FLORIDA....

BLOCK PERSISTS IN UPPER FLOW REGIME OVER THE EASTERN PACIFIC/WESTERN
NORTH AMERICA. MODELS SUGGEST ANOTHER VIGOROUS SHORT WAVE WILL DIG
INTO SOUTHERN BRANCH TROUGH...TO THE SOUTH/WEST OF UPPER HIGH CENTER
OVER BRITISH COLUMBIA...AND THIS IS SUPPORTED BY LATEST SATELLITE
IMAGERY.  AS THIS OCCURS...CYCLONIC CIRCULATION OFF THE PACIFIC
COAST IS PROGGED TO BROADEN...WITH ONE SHORT WAVE PIVOTING WESTWARD
AWAY FROM THE PACIFIC COAST...AND ANOTHER MIGRATING INLAND ACROSS
CALIFORNIA INTO THE GREAT BASIN SATURDAY/SATURDAY NIGHT.

DOWNSTREAM...MERGER OF SPLIT BELTS OF STRONGER FLOW WILL REMAIN TO
THE IMMEDIATE LEE OF THE ROCKIES...WHILE LARGE DEEP CLOSED LOW WILL
CONTINUE TO EVOLVE EAST OF THE MISSISSIPPI VALLEY.  WITHIN THIS 
CIRCULATION...ONE SHORT WAVE TROUGH IS PROGGED TO ROTATE THROUGH ITS
EASTERN/NORTHEASTERN PERIPHERY ACROSS THE ATLANTIC COAST
STATES...WHILE ANOTHER DIGS AROUND ITS WESTERN/SOUTHERN
PERIPHERY...ACROSS THE LOWER OHIO/TENNESSEE VALLEYS.

UPPER PATTERN WILL SUPPORT SLOWLY DEEPENING CYCLONE ACROSS THE LOWER
GREAT LAKES REGION...WHILE SURFACE RIDGING DEVELOPS THROUGH MUCH OF
THE PLAINS/MISSISSIPPI VALLEY INTO THE WESTERN GULF OF MEXICO. 
WHILE AIR MASS WILL BE STABLE...OR IN THE PROCESS OF
STABILIZING...THROUGH MUCH OF THE NATION EAST OF THE ROCKIES...
POTENTIAL FOR VIGOROUS CONVECTIVE DEVELOPMENT MAY EXTEND INTO
SATURDAY ACROSS PARTS OF THE ATLANTIC COAST STATES...BEFORE COLD
FRONT ADVANCES OFFSHORE.

...MID ATLANTIC COAST STATES...
PRE-FRONTAL CONVECTIVE BAND IS EXPECTED TO BE OVERSPREADING
MID/SOUTH ATLANTIC COASTAL AREAS INTO NORTHERN FLORIDA AT 12Z
SATURDAY.  ACTIVITY LIKELY WILL BE WEAK...OR AT LEAST IN PROCESS OF
WEAKENING...AS IT PROGRESSES OFF COASTAL AREAS EARLY IN THE DAY...
AND LINGERING CLOUD COVER/STABILIZING INFLUENCE OF RAIN COOLED AIR
PROVIDES CONSIDERABLE UNCERTAINTY WITH REGARD TO SEVERE THREAT LATER
IN THE DAY.

HOWEVER...MODELS DO SUGGEST MID-LEVEL DRY SLOT WILL NOSE NORTHWARD
IN THE LEE OF THE APPALACHIANS EARLY IN THE DAY...AND THIS WILL
ALLOW FOR AT LEAST NARROW WINDOW OF OPPORTUNITY FOR HEATING AHEAD OF
COLD FRONT DURING THE AFTERNOON HOURS. STRONGEST DESTABILIZATION
APPEARS LIKELY IN A NARROW AXIS FROM CENTRAL NORTH CAROLINA THROUGH
CENTRAL/NORTHERN VIRGINIA...PERHAPS INTO CENTRAL
PENNSYLVANIA...WHERE MIXED LAYER CAPE COULD EXCEED 1000 J/KG AS
STRONGER MID-LEVEL COOLING OVERSPREADS REGION.

AT LEAST SCATTERED INTENSE THUNDERSTORM ACTIVITY IS EXPECTED...AND
SHEAR PROFILES BENEATH 50 TO 70 KT SOUTHERLY MID-LEVEL JET WILL BE
SUFFICIENT FOR SUPERCELLS...PRIMARILY WITH LARGE HAIL. FORCING
ALONG FRONT COULD SUPPORT NARROW SQUALL LINE...WITH A BROADER SCALE
DAMAGING WIND THREAT POSSIBLE ACROSS PARTS OF EASTERN VIRGINIA/NORTH
CAROLINA.

...FLORIDA...
WIND GUSTS/HAIL COULD ACCOMPANY WEAKENING PRE-FRONTAL CONVECTIVE
BAND SPREADING INTO PARTS OF NORTHERN FLORIDA AT 12Z SATURDAY. 
HOWEVER...IT APPEARS LOW-LEVEL CONVERGENCE MAY BECOME FOCUSED NEAR
INTERSECTION OF PRE-FRONTAL TROUGH AND SEA BREEZE ALONG THE EAST
CENTRAL FLORIDA COAST FAIRLY EARLY IN THE DAY. THIS WOULD SEEM
LIKELY TO LIMIT RISK FOR ADDITIONAL STRONG/SEVERE STORMS TO THE
MELBOURNE AREA...BEFORE THIS FORCING DEVELOPS OFFSHORE DURING THE
AFTERNOON.

...INTERMOUNTAIN WEST...
LOWER-LEVELS WILL REMAIN DRY...BUT INFLUX OF MID/HIGH-LEVEL MOISTURE
WILL OCCUR AHEAD OF UPPER TROUGH TODAY THROUGH SATURDAY. 
CONSIDERABLE CLOUD COVER IS EXPECTED TO LIMIT SURFACE HEATING
SOMEWHAT...BUT DESTABILIZATION SHOULD BE SUFFICIENT FOR WIDELY
SCATTERED THUNDERSTORMS OVER A BROAD AREA WEST OF THE CONTINENTAL
DIVIDE.

..KERR.. 04/22/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
WILL PROVIDE DETAILS ON THE TRANSITION.