SWODY1
SPC AC 291221
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0721 AM CDT SAT OCT 29 2011
VALID 291300Z - 301200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS AND DISCUSSION...
AN INTENSE VORTICITY MAXIMUM AND ATTENDANT MIDLEVEL JET STREAK OVER
THE OH/TN VALLEYS WILL LIFT NEWD THROUGH THE MID ATLANTIC STATES
TODAY...SUBSEQUENTLY CONTRIBUTING TO THE FORMATION OF A DEEP-LAYER
CYCLONE OVER NEW ENGLAND TONIGHT. MEANWHILE...AN UPSTREAM SHORTWAVE
TROUGH OVER THE NRN INTERMOUNTAIN REGION IS FORECAST TO AMPLIFY
WHILE TRANSLATING SEWD INTO THE NRN PLAINS AND UPPER MS VALLEY. IN
THE LOW LEVELS...INCREASING LARGE-SCALE FORCING FOR ASCENT ATTENDANT
TO THE FORMER VORTICITY MAXIMUM WILL HASTEN CYCLOGENESIS OFF THE MID
ATLANTIC COAST TODAY WITH THE CYCLONE DEVELOPING TO OFF THE ME COAST
BY 30/12Z. A TRAILING COLD FRONT CURRENTLY ACCELERATING SEWD
THROUGH NRN FL IS EXPECTED TO PROGRESS THROUGH THE REMAINDER OF THE
STATE BY THIS EVENING.
THE COUPLING OF LOW-LEVEL WAA AND DCVA AHEAD OF NEGATIVELY TILTED
MIDLEVEL TROUGH WILL ENHANCE DEEP-LAYER ASCENT ACROSS THE MID
ATLANTIC STATES TODAY...AND INTO CNTRL/SRN NEW ENGLAND TONIGHT.
THIS FORCING WILL ALIGN WITH A SATURATED AND WEAKLY BUOYANT
ENVIRONMENT TO SUPPORT BURSTS OF LIGHTNING ACTIVITY FOR PARCELS
BASED IN THE 850-700 MB LAYER.
OVER FL...THE SEWD-MOVING COLD FRONT WILL SERVE AS THE FOCUS FOR
DIURNALLY ENHANCED TSTMS THIS AFTERNOON WITHIN A VERY MOIST WARM
SECTOR WITH BOUNDARY LAYER DEWPOINTS IN THE 70S AND PW VALUES OF
AROUND TWO INCHES. FORECAST SOUNDINGS EXHIBIT POOR LAPSE
RATES...WHICH WHEN COUPLED WITH RATHER WEAK VERTICAL SHEAR...WILL
PRECLUDE ORGANIZED SEVERE STORM DEVELOPMENT.
OVER THE GREAT LAKES...FORCING FOR ASCENT ASSOCIATED WITH MIDLEVEL
VORTICITY MAXIMUM TRANSLATING ESEWD ACROSS THE REGION WILL ACT ON A
WEAKLY UNSTABLE ENVIRONMENT INVOF THE LAKES TO SUPPORT SPORADIC
LIGHTNING ACTIVITY TODAY INTO THIS EVENING.
..MEAD/HURLBUT.. 10/29/2011
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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