[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 122006
SWODY1
SPC AC 122004

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0204 PM CST SUN MAR 12 2006

VALID 122000Z - 131200Z

...THERE IS A HIGH RISK OF SVR TSTMS OVER EXTREME EASTERN
KANSAS..MUCH OF MISSOURI...SOUTHEAST IOWA..AND WEST
CENTRAL/NORTHWEST ILLINOIS...

...THERE IS A MDT RISK OF SVR TSTMS OVER EASTERN OKLAHOMA..FAR
NORTHEAST TEXAS..ARKANSAS..SOUTHEAST MISSOURI..EASTERN/SOUTHERN
ILLINOIS..INDIANA..AND NORTH CENTRAL/WESTERN KENTUCKY...

...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE ACROSS PARTS OF THE
CENTRAL/SRN PLAINS INTO THE OH VALLEY/SRN GREAT LAKES...

...SIGNIFICANT SEVERE WEATHER OUTBREAK EXPECTED THIS AFTERNOON INTO
TONIGHT...

...SYNOPSIS...
BROAD UPPER TROUGH ACROSS THE WRN HALF OF THE US IS EXPECTED TO MOVE
EWD AS VERY STRONG MID/UPPER LEVEL JET STREAK MOVES EWD ACROSS THE
SRN ROCKIES THIS AFTERNOON AND ACROSS THE CENTRAL PLAINS TONIGHT. 
INCREASING HEIGHT FALLS IN THE LEFT EXIT REGION OF THE JET STREAK
WILL RESULT IN AN UPPER LOW DEVELOPING ACROSS THE NRN PLAINS
TONIGHT.

AT THE SURFACE...A SURFACE LOW NEAR THE CO/KS BORDER WILL GRADUALLY
DEEPEN AS IT MOVES INTO NWRN KS THIS AFTERNOON...CONTINUING ENEWD
ACROSS IA DURING THE OVERNIGHT HOURS. A WELL-DEFINED DRY LINE
CURRENTLY EXTENDING NORTH/SOUTH FROM ERN KS ACROSS CENTRAL OK INTO
WRN PARTS OF CENTRAL WILL MIX EWD THIS AFTERNOON...BEFORE BEING
OVERTAKEN BY A FASTER MOVING COLD FRONT MOVING OUT OF THE HIGH
PLAINS.  THE COLD FRONT WILL CONTINUE EWD TONIGHT REACHING A CENTRAL
IL/CENTRAL AR/SOUTH CENTRAL TX LINE BY 13/12Z. A WARM FRONT
EXTENDING FROM THE SURFACE LOW EWD ACROSS NRN KS AND NRN MO WILL
GRADUALLY LIFT NWD IN ADVANCE OF THE...ALTHOUGH NWD PROGRESS MAY BE
INITIALLY SLOWED BY COLD POOL ASSOCIATED WITH ELEVATED CONVECTION
NORTH OF THE FRONT OVER IA.

...ERN PART OF CENTRAL/SRN PLAINS ACROSS MID MS VALLEY...
SEVERE THUNDERSTORMS HAVE DEVELOPED ACROSS PARTS OF ERN KS
ALONG/AHEAD OF THE DRY LINE...AND ADDITIONAL DEVELOPMENT IS EXPECTED
TO OCCUR SWD ALONG THE DRY LINE INTO OK SHORTLY.  18Z SPECIAL
SOUNDINGS AT OUN AND SGF SHOW MOIST LAYER AROUND 1 KM DEEP WITH
STEEP MID LEVEL LAPSE RATES ABOVE 700-750 MB...CONTRIBUTING TO
UNSTABLE ENVIRONMENT WITH MLCAPE AROUND 2000 J/KG.  MINIMAL CAP ON
THE SOUNDINGS INDICATES STORMS WILL CONTINUE TO DEVELOP NEXT SEVERAL
HOURS IN RESPONSE TO INSOLATION AND WEAK CONVERGENCE ON THE DRY
LINE.  VERY STRONG DEEP LAYER SHEAR /50-60 KT OVER THE LOWEST 6 KM/
ACROSS THE WARM SECTOR WILL ENHANCE STORM ORGANIZATION AND INTENSITY
WITH POTENTIAL FOR LONG-LIVED SUPERCELLS.  STRONG LOW LEVEL SRH OF
150-300 MS/S2 COUPLED WITH FAVORABLY LOW LCL HEIGHTS WILL PROMOTE
DEVELOPMENT OF TORNADIC SUPERCELLS...INCLUDING THREAT FOR SEVERAL
LONG-TRACK STRONG-VIOLENT TORNADOES. VERY LARGE HAIL AND DAMAGING
WIND GUSTS ARE ALSO POSSIBLE.

FARTHER NORTH...CLOUDS ARE DIMINISHING ALONG THE WARM FRONT FROM
NERN KS INTO WEST CENTRAL MO INDICATING HEATING/DESTABILIZATION ARE
INCREASING OVER THIS AREA.  THIS WILL SPREAD INTO NRN MO AND PERHAPS
SRN IA/WEST CENTRAL IL THROUGH THE AFTERNOON HOURS. BACKED LOW LEVEL
WINDS ALONG/NORTH OF THE BOUNDARY ARE FURTHER ENHANCING
SHEAR/HELICITY MAINTAIN A FAVORABLE ENVIRONMENT FOR SUPERCELLS TO
DEVELOP.  ANY SUSTAINED SUPERCELL INTERACTING WITH THE WARM FRONT
WILL HAVE POTENTIAL FOR TORNADIC DEVELOPMENT /INCLUDING A FEW
SIGNIFICANT TORNADOES/ IN ADDITION TO VERY LARGE HAIL AND DAMAGING
WIND GUSTS.

FROM THE EVENING INTO THE OVERNIGHT HOURS...CONVECTION IS EXPECTED
TO CONSOLIDATE INTO ONE OR MORE BANDS OR CLUSTERS OF SEVERE STORMS
ALONG/AHEAD OF THE ADVANCING COLD FRONT AS THEY MOVE EWD TOWARD THE
MS VALLEY.  ALTHOUGH THE SEVERE THREAT MAY TRANSITION TO PRIMARILY
DAMAGING WINDS AND HAIL AFTER 06Z...THE STRENGTHENING LOW LEVEL JET
AND RESULTANT INCREASE IN LOW LEVEL SHEAR/HELICITY SUGGESTS A
CONTINUED THREAT FOR ISOLATED TORNADOES WITH BOWS OR EMBEDDED
SUPERCELLS WITHIN QUASI-LINEAR SEGMENTS.

..WEISS.. 03/12/2006