[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 101231
SWODY1
SPC AC 101230

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0730 AM CDT WED MAY 10 2006

VALID 101300Z - 111200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM LA/MS INTO SWRN KY...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
THE UPPER TX COAST INTO THE OH VALLEY...

...TORNADOES...A FEW STRONG ARE POSSIBLE ACROSS PORTIONS OF THE GULF
STATES INTO THE TN VALLEY...

A SIGNIFICANT SEVERE WEATHER EVENT IS EXPECTED TO EVOLVE ACROSS THE
LOWER MS VALLEY AND CNTRL GULF STATES...NWD ACROSS PORTIONS OF THE
TN VALLEY TODAY.  TORNADOES...POTENTIALLY STRONG...DAMAGING WINDS
AND VERY LARGE HAIL ARE ALSO POSSIBLE PRIOR TO COLD FRONTAL PASSAGE.


THREE MCS CLUSTERS ARE ONGOING EARLY THIS MORNING FROM THE RED RIVER
REGION OF SRN OK/NCNTRL TX...EAST ACROSS AR...AND ANOTHER INTO CNTRL
AL.  THIS EARLY ACTIVITY WILL PLAY AN IMPORTANT ROLE IN FUTURE
DEVELOPMENT/STORM MODE AS BOUNDARY LAYER WARMS TO THE SOUTH OF
CONVECTIVE OUTFLOWS.  OVERNIGHT TRENDS REMAIN SUPPORTIVE OF EARLIER
OUTLOOK...ALTHOUGH CONFIDENCE IN TORNADIC SUPERCELLS HAS RISEN
ACROSS MS INTO NRN AL. THIS ZONE OF HEIGHTENED INTEREST IS
PARTIALLY DUE TO THE INFLUENCE OF OVERNIGHT MCS THAT HAS BACKED LOW
LEVEL FLOW TO THE NORTH OF ASSOCIATED OUTFLOW BOUNDARY.  THIS WILL
MAINTAIN HIGH HELICITY ENVIRONMENT WITHIN STRONGEST ZONE OF LOW
LEVEL WARM ADVECTION WHERE SUPERCELL THUNDERSTORM DEVELOPMENT IS
EXPECTED BY EARLY AFTERNOON.  THERE IS SOME CONCERN THAT
AFOREMENTIONED MCS CLUSTERS COULD HINDER DISCRETE DEVELOPMENT ACROSS
FAR NRN PORTIONS OF MODERATE RISK...HOWEVER SIGNIFICANT CAP ACROSS
SERN TX/LA WILL PREVENT SWD DEVELOPMENT THROUGH MID-LATE MORNING. 
AS A RESULT...VERY UNSTABLE AIR MASS WILL SPREAD NEWD...RETURNING
ATOP STRONGLY SHEARED BUT LESS CAPPED REGION OF THE NCNTRL GULF
STATES.

CURRENT THINKING IS STRONGEST FORCED CONVECTION ALONG COLD FRONT
WILL MAINTAIN N-S LINEAR STRUCTURE AS IT ADVANCES EWD ALONG THE RED
RIVER OF SRN OK/NERN TX.  THIS ACTIVITY SHOULD GRADUALLY EXPAND IN
AREAL COVERAGE...POSSIBLY OVERTAKING DOWNSTREAM CONVECTION OVER AR
BY MID-LATE MORNING.  AN EVER EXPANDING MCS MAY EVOLVE FROM THIS
INTERACTION WITH NEWD DEVELOPMENT INTO THE WRN PORTIONS OF THE TN
VALLEY AS SFC LOW LIFTS NEWD.

DOWNSTREAM...BOUNDARY LAYER HEATING/MOISTENING ATOP MODIFYING
OUTFLOW AIR MASS OVER MS/AL SHOULD ALLOW FOR MORE DISCRETE SUPERCELL
STRUCTURES TO DEVELOP. FORECAST SOUNDINGS FOR THIS
REGION...PARTICULARLY FROM THE 09Z RUC...STRONGLY FAVOR TORNADIC
DEVELOPMENT AS CELL MOTION UTILIZES HIGHER HELICITY ENVIRONMENT. 
OTHER STORMS WILL ALSO DEVELOP ACROSS THE WARM SECTOR AHEAD OF THE
COLD FRONT AS IT ADVANCES EWD INTO LA. VERY STEEP LAPSE RATES AND
EXTREME SBCAPE...IN EXCESS OF 5000 J/KG...WILL AID IN VERY LARGE
HAIL DEVELOPMENT...AS WELL AS ENHANCE DAMAGING WIND POTENTIAL.

MULTIPLE STORM MODES APPEAR LIKELY ACROSS THE MODERATE RISK
REGION...WITH WIDESPREAD SEVERE CONSISTING OF TORNADOES...DAMAGING
HAIL...AND INTENSE WIND.  FRONTAL PASSAGE LATE TONIGHT WILL END
SEVERE THREAT FROM WEST TO EAST.

..DARROW/LEVIT.. 05/10/2006