DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 171731
SWODY2
SPC AC 171729

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1229 PM CDT SUN MAR 17 2013

VALID 181200Z - 191200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MS...AL...NWRN
GA...CNTRL AND ERN KY AND TN...

...SYNOPSIS...
A NEGATIVELY TILTED UPPER TROUGH AXIS WILL EXTEND FROM THE UPPER MS
VALLEY SEWD INTO THE OH VALLEY BY 18Z AND WILL RAPIDLY MOVE NEWD
ACROSS THE GREAT LAKES BY EVENING. HOWEVER...A SECONDARY JET MAX
WILL ALSO STRENGTHEN OVERNIGHT INTO THE MID MS VALLEY...AND WILL
RESULT IN WIDESPREAD HEIGHT FALLS FROM THE OH/TN VALLEYS INTO THE
SERN STATES.

...KY/TN/MS/AL/GA/FL PANHANDLE...
A SURFACE LOW IS FORECAST TO MOVE FROM SRN IL/WRN KY NEWD INTO
INDIANA BETWEEN 12-18Z...WITH A COLD FRONT TRAILING SWWD INTO
TN...NRN MS AND SRN AR. STRONG FORCING FOR ASCENT WILL ACCOMPANY
THIS LOW AND THE NRN PORTION OF THE COLD FRONT IN ASSOCIATION WITH
THE NEGATIVE TILT SHORTWAVE TROUGH. WIDESPREAD RAIN AND
THUNDERSTORMS SHOULD BE ONGOING ACROSS NRN MS/AL...TN...AND KY AS A
RESULT. WITH RELATIVELY STRONG MEAN FLOW...SOME OF THIS CONVECTION
MAY BE SEVERE WITH MAINLY DAMAGING WINDS AND MARGINAL HAIL.

AS FORCING LIFTS NEWD...ATTENTION WILL TURN TO THE TRAILING COLD
FRONT AND WARM SECTOR ACROSS MS/AL/GA/FL. INDICATIONS ARE THAT LOW
CLOUDS SHOULD CLEAR AND ALLOW FOR HEATING AND DESTABILIZATION TO
OCCUR...WITH LOW LEVEL LAPSE RATE PLUME CENTERED OVER MS. MODELS
OFFER A MENAGERIE OF QPF SOLUTIONS THROUGHOUT THE DAY...BUT THE
GENERAL CONSENSUS IS FOR STORMS TO DEVELOP ALONG AND POSSIBLY AHEAD
OF THE WEAK FRONT/LOW PRESSURE TROUGH FROM NRN AL INTO MS AND
PERHAPS AS FAR SW AS ERN LA.
ALTHOUGH LOW LEVEL WINDS WILL BE VEERED...LONG HODOGRAPHS WILL FAVOR
SUPERCELLS CAPABLE OF LARGE HAIL. STEEP MIDLEVEL LAPSE RATES WILL
ALSO BE PRESENT...AND WITH SUFFICIENT LOW LEVEL MOISTURE A FEW
STORMS MAY BE CAPABLE OF SIGNIFICANT HAIL OVER 2 INCHES IN DIAMETER.
VEERED LOW LEVEL FLOW SUGGESTS TORNADO THREAT WILL BE MARGINAL...BUT
NON-ZERO FOR RIGHTWARD MOVING SUPERCELLS. THE PRESENCE OF
SUBSTANTIAL LI/S MAY ALSO TEND TO COMPENSATE FOR THE MARGINAL LOW
LEVEL SHEAR. THE MOST FAVORABLE SHEAR FOR A COUPLE TORNADOES WILL BE
OVER CNTRL AND SRN AL.

OVERNIGHT...AN UNSTABLE AND RELATIVELY UNCAPPED AIR MASS WILL REMAIN
ALONG THE CNTRL GULF COAST AND ACROSS THE FL PANHANDLE. ISOLATED
SEVERE ACTIVITY MAY THUS PERSIST AS IT TRAVELS SEWD OUT OF AL. A FEW
SUPERCELLS MAY ALSO EXIST ALONG THE FRONT OVER THE GULF OF
MEXICO...AND COULD THREATEN PORTIONS OF THE FL COAST LATE.

..JEWELL.. 03/17/2013

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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.