[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 081731
SWODY2
SPC AC 081730

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CST WED MAR 08 2006

VALID 091200Z - 101200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER TO MID
MS VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
PLAINS...OZARKS...OH VALLEY AND TN VALLEY...

...MS VALLEY...
AN IMPRESSIVE UPPER-LEVEL TROUGH OVER THE DESERT SW WILL EJECT EWD
TONIGHT DEEPENING AND BECOMING NEGATIVELY TILTED OVER THE SRN PLAINS
THURSDAY. AHEAD OF THIS POTENT UPPER-TROUGH LARGE-SCALE ASCENT WILL
BECOME INCREASINGLY FOCUSED AS A 100 KT MID-LEVEL JET PUNCHES INTO
THE LOWER MS VALLEY. RICH LOW-LEVEL MOISTURE AHEAD OF THE SYSTEM
COMBINED WITH VERY STRONG WIND SHEAR PROFILES SUGGEST THE POTENTIAL
FOR A MAJOR SEVERE WEATHER OUTBREAK EXISTS FOR THURSDAY AND THURSDAY
NIGHT ACROSS THE LOWER TO MID MS VALLEY.

A LARGE COMPLEX OF THUNDERSTORMS WILL LIKELY BE ONGOING AT THE
BEGINNING OF THE PERIOD AS THE TROUGH SWINGS EWD INTO THE SRN
PLAINS. AT 12Z MODEL CONSENSUS PLACES A SQUALL-LINE OR BROKEN LINE
OF STORMS ALONG THE WEST EDGE OF A WELL-DEVELOPED LOW-LEVEL JET WITH
THE LINE EXTENDING SWWD FROM THE LOWER OH VALLEY ACROSS THE OZARKS
INTO THE SRN PLAINS. AHEAD OF THE UPPER-LEVEL TROUGH THE STRONG
LOW-LEVEL FLOW SHOULD TRANSPORT SFC DEWPOINTS IN THE 60S F AS FAR
NORTH AS SRN IL DURING THE DAY. THIS COMBINED WITH THE PROGRESSIVE
AND VERY WELL-DEVELOPED NATURE OF THE UPPER-TROUGH SUGGESTS THAT
INSTABILITY WILL BE SUFFICIENT FOR SEVERE STORMS. IN ADDITION...THE
15Z TO 18Z FORECAST SOUNDINGS ACROSS THE REGION ON THURSDAY SHOW
IMPRESSIVE SHEAR PROFILES WITH STRONG LOW TO MID-LEVEL VEERING AND
SUFFICIENT SPEED SHEAR FOR SUPERCELLS WITH WELL-DEVELOP LOW-LEVEL
MESOCYCLONES.

ALTHOUGH NOT YET CERTAIN...A TORNADO OUTBREAK WILL BE POSSIBLE
ESPECIALLY IF A LARGE NUMBER OF STORMS REMAIN DISCRETE AS THE
INITIAL LARGE CLUSTER OF STORMS DRIFTS EWD AND EXPANDS FROM NORTH TO
SOUTH ACROSS THE MS VALLEY DURING THE AFTERNOON. THE BEST POTENTIAL
FOR LONG TRACK STRONG OR VIOLENT TORNADOES SHOULD BE WHERE
INSTABILITY IS LOCALLY MAXIMIZED AND JUST AHEAD OF THE SFC LOW AND
IN THE NOSE OF THE MID-LEVEL JET. IF THE MAJORITY OF THE STORMS
REMAIN LINEAR INSTEAD OF DISCRETE...A WIDESPREAD WIND DAMAGE EVENT
WOULD BE MORE LIKELY AS A SQUALL-LINE MOVES EWD ACROSS THE REGION.
WIND GUSTS ABOVE 70 KTS AND LARGE HAIL ABOVE 2 INCHES WOULD BE
POSSIBLE WITH THE SUPERCELLS AND BOW ECHOES EMBEDDED IN OR AHEAD OF
THE LINE. THE HEAVIEST CONCENTRATION OF SEVERE WEATHER EVENTS SHOULD
BE ALONG THE MOIST AXIS ACROSS AR...LA...MS AND WRN TN ALTHOUGH SOME
SEVERE WEATHER WILL BE POSSIBLE AS FAR NORTH AS THE OH VALLEY AND
SRN LOWER MI DUE TO THE STRONG MID-LEVEL FLOW AS THE LEFT EXIT
REGION OF THE MID-LEVEL JET PASSES ACROSS THE REGION THURSDAY NIGHT.
DURING THE NIGHT...A SOLID LINE SHOULD DRIFT EWD ACROSS THE OH AND
TN VALLEYS WITH THE SEVERE WEATHER THREAT GRADUALLY DECREASING.

...WEST COAST...
MODEL FORECASTS DEVELOP AN UPPER-LEVEL TROUGH ALONG THE WEST COAST
THURSDAY SPREADING STRONG LARGE-SCALE ASCENT INTO WA...ORE AND CA
THURSDAY NIGHT. AS THIS OCCURS...STEEP MID-LEVEL LAPSE RATES
ASSOCIATED WITH THE TROUGH MAY BE ENOUGH FOR SCATTERED THUNDERSTORM
DEVELOPMENT ALONG THE IMMEDIATE COASTAL AREAS. HOWEVER...INSTABILITY
AND SHEAR IS NOT EXPECTED TO BE STRONG ENOUGH FOR AN OUTLOOK AREA OF
SEVERE WEATHER THURSDAY NIGHT.

..BROYLES.. 03/08/2006