Tuesday, October 23, 2007

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 231233
SWODY1
SPC AC 231230

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0730 AM CDT TUE OCT 23 2007

VALID 231300Z - 241200Z

..NO SVR TSTM AREAS FORECAST...

..DEEP SOUTH INTO THE SOUTHEASTERN U.S...
MESSY CONVECTIVE FORECAST AS SLOW MOVING UPPER LOW CLOSING OFF OVER
THE LOWER MS RIVER VALLEY LAGS WELL WEST OF A SURFACE COLD FRONT
FORECAST TO PUSH EWD ACROSS AL TODAY. 12Z SURFACE ANALYSIS
INDICATES OVERNIGHT CONVECTION HAS REINFORCED A WARM FRONT/OUTFLOW
BOUNDARY INTO SRN AL/SRN GA WHERE GREATEST THETA-E GRADIENT IS NOW
FOCUSED. IN ADDITION...WEAK SURFACE WAVE HAS FORMED NEAR MOB AT 12Z
ALONG TRIPLE POINT WITH THIS FRONT AND STRONG EWD MOVING COLD FRONT.
SURFACE FRONT SHOULD LOSE SOME EWD MOMENTUM THROUGH THE DAY AS UPPER
SYSTEM REMAINS WEST AND LOW-DEEP FLOW FIELDS BECOME MORE MERIDIONAL
WITH TIME...LEAVING WEAKENING CONVERGENCE AND LIMITED DEEP ASCENT
OVER THE SOUTHEAST.

AHEAD OF THE COLD FRONT...A LARGE AREA OF MARITIME TROPICAL AIR IS
ALREADY IN PLACE WITH SURFACE DEW POINTS IN THE LOWER 70S SPREADING
INTO THE SRN APPALACHIANS AND ACROSS MUCH OF GA EARLY THIS MORNING.
ALTHOUGH STRONGEST LLJ NOW SUPPORTING BROAD AREA OF WAA
PRECIPITATION FROM THE TN VALLEY ACROSS THE OH RIVER VALLEY WILL
LIFT NEWD THROUGH THE DAY...20-30 KT SSWLY H85 FLOW WILL REMAIN IN
PLACE FROM SERN AL/FL PANHANDLE INTO THE SRN APPALACHIANS. THIS
SHOULD MAINTAIN FAVORABLE LOW AND DEEP LAYER SHEAR FOR ROTATION AND
ORGANIZATION INTO SMALL LINES WITH ANY ENSUING THUNDERSTORM
DEVELOPMENT WITHIN BROAD WARM SECTOR. HOWEVER...INSTABILITY INLAND
FROM THE GULF MAY BE QUITE MARGINAL AND SHOULD TEND TO LIMIT EXTENT
OF ANY SEVERE THREAT TODAY. DESPITE WEAK LAPSE RATES/INSTABILITY...
VERY MOIST BOUNDARY LAYER CONDITIONS AND AMPLE DEEP LAYER SHEAR
WARRANT AT LEAST LOW PROBABILITIES FOR ISOLATED DAMAGING WIND GUSTS
OR PERHAPS A TORNADO. SHOULD A DEFINITIVE FOCUS BECOME EVIDENT LATER
TODAY...HIGHER PROBABILITIES AND A SMALL SLGT RISK MAY BE REQUIRED.

.EVANS/CROSBIE.. 10/23/2007

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.

No comments: