SWODY2
SPC AC 280526
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1226 AM CDT SUN SEP 28 2008
VALID 291200Z - 301200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
THE UPPER FLOW REGIME FROM THE EASTERN PACIFIC INTO THE WESTERN U.S.
IS IN THE PROCESS OF BECOMING INCREASINGLY AMPLIFIED. AND...BY
EARLY MONDAY...MODELS SUGGEST THAT THE AXIS OF AN ELONGATED CENTER
OF A STRONG RIDGE WILL BECOME ESTABLISHED IN A NORTH-SOUTH FASHION
ACROSS THE EASTERN GREAT BASIN AND ROCKIES. TO THE EAST OF THIS
FEATURE...A SIGNIFICANT DIGGING SHORT WAVE TROUGH APPEARS LIKELY TO
TURN MORE SHARPLY SOUTHEASTWARD ACROSS THE UPPER MISSISSIPPI VALLEY.
AS THIS SYSTEM PROGRESSES INTO THE LOWER OHIO/TENNESSEE VALLEYS
LATE MONDAY INTO EARLY TUESDAY...MODELS ARE SUGGESTIVE OF INCREASED
PHASING WITH AN UPPER TROUGH OVER THE GULF COAST/GULF OF
MEXICO...EMBEDDED WITHIN A BELT OF WESTERLIES EXTENDING ACROSS THE
NORTHERN MEXICAN PLATEAU THROUGH THE LOWER LATITUDE WESTERN
ATLANTIC.
THE EVOLVING PATTERN WILL FAVOR THE CONTINUED EROSION OF AN ELEVATED
MIXED LAYER TO THE LEE OF THE ROCKIES...WHILE REMAINING UNFAVORABLE
FOR THE DEVELOPMENT OF A SOUTHERLY RETURN FLOW OF MOISTURE OFF THE
GULF OF MEXICO. SIGNIFICANT MOISTURE EAST OF THE ROCKIES APPEARS
LIKELY TO REMAIN CONFINED TO PARTS OF THE CENTRAL/SOUTHERN FLORIDA
PENINSULA. MEANWHILE...DRY CONDITIONS WILL PERSIST ACROSS MUCH OF
THE WEST...BUT SOME MOISTENING MAY BEGIN TO OCCUR ON SOUTHERLY FLOW
TO THE WEST OF THE UPPER RIDGE AXIS...ACROSS THE PACIFIC COAST
STATES AND PARTS OF THE WESTERN GREAT BASIN.
...MIDDLE MISSISSIPPI/LOWER OHIO VALLEYS...
GUIDANCE CONTINUES TO INDICATE THAT AN AREA OF STRONG FORCING FOR
UPWARD VERTICAL MOTION AND MID-LEVEL COOLING WILL ACCOMPANY AN
INITIAL JET STREAK /AROUND 50 KT AT 500 MB/ ASSOCIATED WITH THE
DIGGING UPPER TROUGH...ACROSS PARTS OF ILLINOIS/MISSOURI DURING THE
PEAK AFTERNOON HEATING HOURS. DESPITE MODEST MOISTURE LEVELS AND
WEAK LOW-LEVEL FLOW/FORCING...FORECAST SOUNDINGS ARE SUGGESTIVE OF
SUFFICIENT DESTABILIZATION FOR AT LEAST SCATTERED STORMS...A FEW OF
WHICH MAY BE CAPABLE OF PRODUCING HAIL/LOCALIZED GUSTS WHICH COULD
APPROACH OR BRIEFLY EXCEED SEVERE LIMITS.
...FLORIDA...
LARGE-SCALE FORCING AHEAD OF THE SOUTHERN UPPER TROUGH IS EXPECTED
TO BE CONDUCIVE TO CONVECTIVE DEVELOPMENT ACROSS THE
CENTRAL/SOUTHERN PENINSULA. BUT...THERMODYNAMIC/KINEMATIC PROFILES
EXHIBITING WEAK LAPSE RATES AND WEAK LOW/MID-LEVEL FLOW FIELDS ARE
EXPECTED TO MINIMIZE THE RISK FOR SEVERE STORMS.
...PACIFIC COAST STATES/WESTERN GREAT BASIN...
ENOUGH MOISTENING IS EXPECTED TO OCCUR BY MONDAY FOR AT LEAST WIDELY
SCATTERED AFTERNOON THUNDERSTORMS...DRIVEN PRIMARILY BY DAYTIME
HEATING/OROGRAPHIC FORCING...ACROSS THE MOUNTAINS AND DESERTS OF
SOUTHERN CALIFORNIA...THE SIERRA NEVADA INTO THE SHASTA/SISKIYOU
REGION AND SOUTHERN CASCADES...AND THE HIGHER TERRAIN OF NEVADA.
..KERR.. 09/28/2008
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.
No comments:
Post a Comment