Sunday, April 22, 2012

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 221243
SWODY1
SPC AC 221242

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0742 AM CDT SUN APR 22 2012

VALID 221300Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS TODAY ACROSS FAR ERN NC...

...SYNOPSIS...

POTENT MIDLEVEL JET STREAK OVER THE OZARKS WILL DIG SEWD INTO THE
SERN STATES TODAY...CONTRIBUTING TO SIGNIFICANT INTENSIFICATION OF
ERN CONUS TROUGH...AND SUBSEQUENT UPPER LOW FORMATION ACROSS THE
CNTRL APPALACHIANS TO MID-ATLANTIC COAST. THIS PATTERN EVOLUTION
WILL RESULT IN THE RAPID NEWD PROGRESSION AND DE-AMPLIFICATION OF
SHORTWAVE TROUGH NOW OVER FL.

IN THE LOW-LEVELS...CYCLONE OFF THE GA/SC COASTS WILL CONCURRENTLY
DEEPEN WHILE DEVELOPING NNEWD ACROSS THE NC OUTER BANKS BEFORE
CURVING NWWD ONTO THE MID-ATLANTIC COAST LATE TONIGHT INTO MONDAY
MORNING.

...FAR ERN NC TODAY...

DEEP-LAYER FORCING FOR ASCENT AND VERTICAL SHEAR WILL STRENGTHEN
TODAY AHEAD OF MIGRATORY SURFACE LOW AND DEEPENING UPPER SYSTEM.
HOWEVER...WIDESPREAD CLOUDS AND PRECIPITATION WILL LIMIT DAYTIME
HEATING WITH ENVIRONMENT REMAINING ONLY MARGINALLY UNSTABLE DESPITE
BOUNDARY LAYER DEWPOINTS IN THE MID 60S. CURRENTLY...IT APPEARS THE
GREATEST RISK FOR A TORNADO AND/OR DAMAGING WIND GUST WILL EXIST
ACROSS THE OUTER BANKS THROUGH THIS AFTERNOON...ALONG/E OF LOW TRACK
WHERE CONVERGENCE AND VERTICAL SHEAR WILL BE MAXIMIZED.

...PACIFIC NW INTO NRN ROCKIES THIS AFTERNOON/EVENING...

12Z REGIONAL SOUNDINGS INDICATE THE PRESENCE OF STEEP MIDLEVEL LAPSE
RATES AND PW VALUES OF .5-1.0 INCH WHICH WILL COMBINE WITH DAYTIME
HEATING TO YIELD AFTERNOON MLCAPE VALUES APPROACHING 1000-1500 J/KG.
MOREOVER...MIDLEVEL WIND FIELD WILL GRADUALLY BACK AND STRENGTHEN
TODAY WITH THE SLIGHT EWD PROGRESSION OF UPPER RIDGE...RESULTING IN
40+ KT OF DEEP SWLY SHEAR. THOUGH ENVIRONMENT IS EXPECTED TO BECOME
INCREASINGLY SUPPORTIVE OF ORGANIZED STORM MODES...INCLUDING
SUPERCELLS...UNCERTAINTY EXISTS WITH REGARD TO TSTM COVERAGE LATE
THIS AFTERNOON INTO EVENING. THEREFORE...ONLY LOW WIND/HAIL
PROBABILITIES WILL BE INCLUDED IN THIS FORECAST.

..MEAD/LEITMAN.. 04/22/2012

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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: