[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 091745
SWODY2
SPC AC 091744

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1244 PM CDT TUE MAY 09 2006

VALID 101200Z - 111200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM THE CONFLUENCE OF THE OH/MS
RIVERS SWD ACROSS THE LOWER MS VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
SERN TX TO LOWER MI TO GA AND NRN FL...

...WIDESPREAD AND POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE
APPEARS INCREASINGLY LIKELY OVER PARTS OF THE MS/TN VALLEYS AND
LOWER OH VALLEY DURING WEDNESDAY...

...SYNOPSIS...
MID/UPPER LEVEL FLOW OVER THE CNTRL U.S. WILL CONTINUE TO UNDERGO
STRONG AMPLIFICATION THROUGH MIDWEEK AS LARGE SCALE PHASING BETWEEN
MIDDLE AND NRN BRANCH FLOW PRODUCES AN ANOMALOUSLY DEEP CYCLONE
ACROSS THE MIDWEST. THIS LARGE SCALE EVOLUTION WILL UNFOLD AS STRONG
MIDDLE STREAM SHORT WAVE TROUGH DEVELOPS EAST ACROSS THE SRN PLAINS
THROUGH LATE TUESDAY EVENING. THIS IMPULSE IS EXPECTED TO INDUCE
STRONG MCS DEVELOPMENT ACROSS OK THROUGH TUESDAY NIGHT. SRN PLAINS
SURFACE LOW IS FORECAST TO STRENGTHEN COINCIDENT WITH THE MCS AND
SPREAD EAST TO NEAR THE MO BOOTHEEL AREA BY WEDNESDAY MORNING.
SLOWER MOVING NRN BRANCH SHORT WAVE TROUGH/LOW WILL DEVELOP ESEWD
FROM MT TOWARD THE UPPER MS VALLEY THROUGH WEDNESDAY AFTERNOON.
STRONG COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL SPREAD QUICKLY
SWD/SEWD ACROSS THE PLAINS AND MERGE WITH THE DEEPENING CYCLONE
ACROSS THE LOWER OH VALLEY DURING WEDNESDAY AFTERNOON. WHILE PRIMARY
DEEP LAYER CYCLONE ASSOCIATED WITH THE NRN BRANCH TROUGH UNDERGOES
OCCLUSION OVER LAKE MI...INTENSIFYING SECONDARY CYCLONE IS FORECAST
TO TRACK NNEWD ACROSS THE MIDWEST... AND INTO LOWER MI...THROUGH
WEDNESDAY EVENING. TRAILING COLD FRONT WILL SWEEP EWD ACROSS THE
MID/LOWER MS VALLEY...AND ACROSS MUCH OF THE DEEP SOUTH AND OFF THE
NCNTRL GULF COAST...THROUGH EARLY THURSDAY.

...SERN MO TO LOWER MI...
POTENTIAL EXISTS FOR WIDESPREAD CLOUDS AND PRECIPITATION TO SOMEWHAT
IMPEDE AIR MASS MODIFICATION ACROSS THE LOWER OH VALLEY DURING
WEDNESDAY GIVEN PRESENCE OF UPSTREAM MCS ACTIVITY AND STRONG OUTFLOW
BOUNDARIES. HOWEVER...GFS AND ENSEMBLE FORECASTS SUPPORT AT LEAST
MODEST RECOVERY IN THE WAKE OF MORNING CONVECTION AND AHEAD OF
APPROACHING MID LEVEL WIND MAX AND DEEPENING SURFACE LOW. GIVEN LOW
TO MID 60S SURFACE DEWPOINTS AND POCKETS OF MLCAPE AROUND 500 J/KG
/POSSIBLY HIGHER IF GFS FORECAST VERIFIES/ SHEAR AND FORCING APPEAR
MORE THAN ADEQUATE TO PROMOTE STORM ORGANIZATION INTO LINE SEGMENTS
AND LOW TOPPED SUPERCELLS. THIS ACTIVITY SHOULD SPREAD ENEWD ACROSS
THE LOWER OH VALLEY AND LOWER MI FROM AFTERNOON THROUGH EVENING WITH
AN INCREASING CHANCE FOR HAIL AND HIGH WINDS. TORNADO POTENTIAL
APPEARS GREATEST NEAR THE INTENSIFYING SURFACE LOW. IF MODEST TO
STRONG INSTABILITY CAN DEVELOP COINCIDENT WITH THIS FEATURE...A
COUPLE OF STRONG TORNADOES APPEAR POSSIBLE.

...LOWER MS VALLEY/TN VALLEY/DEEP SOUTH...
SOUTH OF THE SURFACE LOW...WIDESPREAD MOISTURE AND INCREASING
INSTABILITY SHOULD EXIST. OUTFLOW FROM POSSIBLE OK/AR MCS MAY SPREAD
SEWD INTO AND INHIBIT STRONGER AIR MASS DESTABILIZATION EARLY IN THE
DAY. HOWEVER...STRONG RECOVERY IS EXPECTED IN THE WAKE OF THIS
OUTFLOW...FROM TXK ACROSS THE LOWER MS VALLEY BY AFTERNOON.
DIFFLUENT AND INCREASINGLY STRONG WLY MID LEVEL FLOW WILL SPREAD
ACROSS THE RECOVERING WARM SECTOR AND FOSTER NEW CONVECTION AHEAD OF
THE COLD FRONT FROM AR ACROSS THE MS RIVER. THIS ACTIVITY WILL EXIST
WITHIN A STRONGLY SHEARED ENVIRONMENT AND NUMEROUS SUPERCELLS WITH
LARGE HAIL AND DAMAGING WINDS APPEAR POSSIBLE. IF THIS CONVECTION
CAN REMAIN DISCRETE THROUGH LATE AFTERNOON...STORMS WILL MOVE INTO
HIGH HELICITY REGIME EXISTING IN THE WAKE OF EARLIER MCS OUTFLOW.
TORNADIC STORMS APPEAR POSSIBLE BEFORE CONVECTION BECOMES
INCREASINGLY LINEAR AS INTENSIFYING COLD FRONT DEVELOPS INTO THE
REGION. WIND DAMAGE AND ISOLATED TORNADO THREAT MAY EXTEND BEYOND
SUNSET AS SEVERE SQUALL LINE DEVELOPS ESEWD ACROSS THE NRN GULF
COAST/DEEP SOUTH.

..CARBIN.. 05/09/2006