[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 091636
SWODY1
SPC AC 091635

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE
1035 AM CST THU MAR 09 2006

VALID 091630Z - 101200Z

...THERE IS A MDT RISK OF SVR TSTMS LOWER MISSISSIPPI VALLEY THROUGH
MIDDLE TENNESSEE VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS CENTRAL GULF COAST STATES INTO
THE OH RIVER VALLEY...

...SYNOPSIS...
MORNING MODELS AND ONGOING OBSERVATIONAL TRENDS SUGGEST LITTLE
CHANGE NEEDED TO ONGOING OUTLOOK/SCENARIO ATTM.  STRONG MID/UPPER
SYSTEM EJECTING AS A FAST-MOVING...NEGATIVELY-TILTED SHORTWAVE
TROUGH ACROSS THE MID SOUTH TODAY AND INTO THE LOWER GREAT LAKES BY
THE END OF THE PERIOD. SUBSTANTIAL MID LEVEL JET MAX WITH H5 WINDS
IN EXCESS OF 80 KT WILL PROGRESS EWD ACROSS A LARGE PORTION OF THE
LOWER/MID MS AND TN RIVER VALLEYS.

...LOWER OH RIVER VALLEY INTO LOWER/MID MS AND TN RIVER VALLEYS...
ONGOING CONVECTION THIS MORNING WILL CONTINUE TO MOVE EASTWARD THIS
MORNING WITH DRY SLOT ALREADY SPREADING THROUGH EASTERN TX AND
WESTERN AR.  SUFFICIENT MOMENTUM MIXING DOWN TO THE SURFACE BEHIND
THUNDERSTORM LINES...MARGINAL INSTABILITY AHEAD OF SYSTEM...AND
STRONG SHEAR WILL COMBINE TO PRODUCE MULTIPLE LINES OF THUNDERSTORMS
WITH A FEW DISCRETE CELLS AHEAD OF AND EMBEDDED WITHIN THE LINES. 
SHEAR IS QUITE IMPRESSIVE OVER MOST OF THE REGION WITH AREA VWP/S
AND PROFILERS INDICATING 0-1/0-2 KM SRH IN EXCESS OF 300 M2/S2 AND
SFC-6 KM SHEAR EXCEEDING 80 KT.

LIMITING FACTOR ATTM IS LACK OF SIGNIFICANT INSTABILITY AHEAD OF
LINE.  SURFACE DEW POINTS IN THE LOW 60S WITH SURFACE TEMPERATURES
IN THE LOW 70S WILL PROVIDE ENOUGH INSTABILITY FOR A FEW DISCRETE
CELLS AND A POTENTIAL FOR ISOLATED STRONG TORNADOES AHEAD AND/OR
EMBEDDED WITHIN THE SQUALL LINE...HOWEVER DONT EXPECT THIS TO BE
WIDESPREAD.  STRONG FORCING AND STRENGTH OF LOW LEVEL SHEAR SUGGEST
MULTIPLE LINES OF THUNDERSTORMS WITH SIGNIFICANT WIND DAMAGE DUE TO
UPPER LEVEL MOMENTUM MIXING DOWN TO THE SURFACE COMBINED WITH QUICK
MOVING STORMS.

AS THE MAIN TROUGH LIFTS NEWD INTO THE OH VALLEY TONIGHT...THE
STRONGER FORCING WILL BECOME MORE REMOVED FROM THE INSTABILITY.
STORMS WITH MAINLY A WIND THREAT WILL SPREAD EWD INTO ERN KY SWD
INTO WRN GA...THOUGH THE SEVERE THREAT SHOULD GRADUALLY DIMINISH
THROUGH THE NIGHTTIME HOURS.

...LOWER OH/MID MS RIVER VALLEYS INTO THE LOWER GREAT LAKES...
ISOLATED LARGE HAIL AND POSSIBLY DAMAGING WINDS WILL ACCOMPANY
MORNING STORMS CURRENTLY OVERSPREADING COOL BOUNDARY LAYER NORTH OF
EFFECTIVE WARM FRONT/OUTFLOW BOUNDARY EXTENDING FROM WRN KY INTO
CENTRAL AR.  HOWEVER AS LOW CENTER DEEPENS ACROSS THE MID MS RIVER
VALLEY...INSTABILITY AND SUBSEQUENT THUNDERSTORMS MAY BECOME MORE
SURFACE BASED WITH DAMAGING WINDS AND POSSIBLY TORNADOES AS SHEAR
REMAINS SUPPORTIVE OF SUPERCELLS AND SMALL LINES.

..AFWA.. 03/09/2006