[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 102003
SWODY1
SPC AC 102001

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0301 PM CDT WED MAY 10 2006

VALID 102000Z - 111200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER MS
VALLEY FROM NERN LA...OVER SCNTRL MS AND SWRN AL...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE TX GULF COAST ACROSS
THE LOWER OH VALLEY TO LOWER MI...

...SYNOPSIS...
COMPLEX AND POTENTIALLY VOLATILE SEVERE WEATHER SITUATION NOW
UNFOLDING ACROSS THE LOWER MS VALLEY AND DEEP SOUTH.
ADDITIONALLY...SEVERE STORM POTENTIAL IS EXPECTED TO INCREASE ACROSS
PARTS OF THE LOWER OH VALLEY AND MIDWEST FROM LATE THIS AFTERNOON
INTO THE EVENING.

STRONG DYNAMIC FORCING ASSOCIATED WITH A POTENT SHORT WAVE TROUGH
AND 70KT MID LEVEL WIND MAX WILL CONTINUE TO OVERSPREAD VERY
UNSTABLE AIR MASS ACROSS PARTS OF LA...MS...AL...AND THE FL
PANHANDLE OVER THE NEXT FEW HOURS. AS THE MID/UPPER LEVEL SYSTEM
SWINGS EWD/NEWD ACROSS THESE AREAS...RAPID SURFACE CYCLOGENESIS WILL
OCCUR ALONG A STRENGTHENING FRONTAL ZONE SITUATED FROM LAKE MI SWD
TO THE CONFLUENCE OF THE OH/MS RIVERS. THE SURFACE LOW WILL DEEPEN
RAPIDLY TONIGHT WHILE TRACKING INTO SRN LOWER MI. THE COLD FRONT
ASSOCIATED WITH THIS CYCLONE WILL ACCELERATE ESEWD ACROSS THE
MID/LOWER MS VALLEY THROUGH LATE THIS EVENING.

...LA...SRN MS/AL...WRN FL PNHDL...
OUTFLOW FROM A PAIR OF MATURE MESOSCALE CONVECTIVE SYSTEMS CROSSING
NRN MS/AL HAS STRONGLY REINFORCED FRONTAL ZONE/WARM FRONT SITUATED
FROM NERN LA EWD TO SWRN AL. MEANWHILE...COLD FRONT WAS ADVANCING
EAST AND INTERSECTS THE WRN EXTENSION OF THE WARM FRONT ACROSS NRN
LA. AIR MASS AHEAD OF AND ALONG THESE BOUNDARIES HAS BECOME
EXTREMELY UNSTABLE WITH LATEST DIAGNOSTIC DATA INDICATING MLCAPE
AROUND 3000 J/KG. MESOSCALE FORCING/ASCENT NEAR THE FRONTS...IN
COMBINATION WITH DIURNAL HEATING...WILL CONTINUE TO PROMOTE
SURFACE-BASED TSTM DEVELOP ACROSS THE WARM SECTOR THROUGH THIS
EVENING. THIS ACTIVITY WILL OCCUR ALONG THE SRN EDGE OF THE FASTER
MID LEVEL TROPOSPHERIC FLOW...AND WITHIN A KINEMATIC ENVIRONMENT
CHARACTERIZED BY PRIMARILY UNIDIRECTIONAL SHEAR SUPPORTIVE OF
SUPERCELLS. IN ADDITION TO VERY LARGE HAIL AND HIGH WINDS WITH THIS
CONVECTION...A FEW TORNADOES WILL ALSO BE POSSIBLE...ESPECIALLY FROM
DISCRETE CELLS TRACKING NEAR/ALONG THE OUTFLOW-REINFORCED BOUNDARY
FROM ERN LA ACROSS SCNTRL MS AND INTO SWRN AL OVER THE NEXT SEVERAL
HOURS.

...TX GULF COAST...
COLD FRONT WILL CONTINUE TO DEVELOP SEWD INTO STRONG TO EXTREME
INSTABILITY ALONG THE TX COAST FROM BRO THROUGH HOU. ALTHOUGH LACK
OF STRONGER LARGE SCALE FORCING AND STRONG CAP MAY INHIBIT
CONVECTIVE DEVELOPMENT WITH SWD/SWWD EXTENT ALONG THE FRONT...
LATEST SHORT-TERM GUIDANCE INDICATES AT LEAST SCATTERED STRONG TO
SEVERE STORM DEVELOPMENT COULD OCCUR AS THE BOUNDARY MOVES ACROSS
THE COASTAL PLAIN...AND EVEN INTO DEEP SOUTH TX...THROUGH THE
EVENING. VERY LARGE HAIL...WIND DAMAGE...AND A COUPLE OF TORNADOES
APPEAR POSSIBLE WITH THIS ACTIVITY GIVEN MORE THAN ADEQUATE DEEP
LAYER SHEAR FOR UPDRAFT ROTATION/ORGANIZATION.

...NERN AR/SERN MO NEWD ACROSS THE MIDWEST TO LOWER MI...
VERY COMPLICATED FORECAST SCENARIO ACROSS THESE AREAS THROUGH THIS
EVENING. AIR MASS DESTABILIZATION HAS BEEN STRONGLY HINDERED BY THE
PASSAGE OF A SERIES OF STORM COMPLEXES FARTHER SOUTH AND EAST. WEAK
AIR MASS RECOVERY WAS NOW UNDERWAY ACROSS AR/SERN MO AND GRADUAL
DESTABILIZATION MAY OCCUR COINCIDENT WITH CYCLOGENESIS OVER THE
LOWER OH VALLEY THROUGH LATE AFTERNOON. ANOTHER POCKET OF WEAK
INSTABILITY EXISTS ACROSS NRN IL/IND AND INTO LOWER MI WHERE
MARGINAL HEATING HAS CONTRIBUTED TO WEAKLY CAPPED MLCAPE AROUND 500
J/KG. TSTMS WERE DEVELOPING ACROSS THESE AREAS AS STRENGTHENING
LARGE SCALE FORCING FOR ASCENT BEGINS TO ACT ON THE MARGINALLY
UNSTABLE AIR MASS.

STRONG DYNAMICS ASSOCIATED WITH RAPID HEIGHT FALLS AND INTENSIFYING
MID LEVEL WINDS WILL LIKELY RESULT IN AN INCREASINGLY FAVORABLE
ENVIRONMENT FOR ROTATING STORMS THROUGH THIS EVENING. ENHANCED LOW
LEVEL SHEAR AND HIGH BOUNDARY LAYER RH NEAR THE DEEPENING SURFACE
LOW COULD LEAD TO AN INCREASING POSSIBILITY OF TORNADOES IF
SUFFICIENT INSTABILITY CAN DEVELOP TO MAINTAIN MODEST TO STRONG
STORM UPDRAFTS. AREAS FROM THE LOWER OH RIVER VALLEY... NWD INTO
LOWER MI...WILL NEED TO BE MONITORED CLOSELY FOR STORM EVOLUTION
THROUGH THE EVENING. CURRENTLY...LIMITED INSTABILITY AND
UNCERTAINTIES REGARDING AIR MASS RECOVERY SUGGEST MAINTAINING
RELATIVELY LOW SEVERE WEATHER/TORNADO PROBABILITIES OVER THE REGION.

..CARBIN.. 05/10/2006