[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 231746
SWODY2
SPC AC 231745

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1245 PM CDT WED AUG 23 2006

VALID 241200Z - 251200Z

...THERE IS A SLGT RISK OF SVR TSTMS NRN PLAINS TO UPPER MS
VALLEY...

...SYNOPSIS...
STRONG SHORT WAVE TROUGH WAS CURRENTLY MOVING ACROSS THE PACIFIC
NORTHWEST AND WILL TRACK EAST ACROSS THE NRN ROCKIES THROUGH
TONIGHT. HEIGHT FALLS AND WIDESPREAD UPWARD VERTICAL MOTION
ASSOCIATED WITH THIS SYSTEM ARE FORECAST TO EMERGE OVER THE NRN HIGH
PLAINS THURSDAY MORNING BEFORE DEVELOPING EAST ACROSS THE NRN/CNTRL
PLAINS AND UPPER MS VALLEY THROUGH THURSDAY NIGHT. AS PRIMARY
RESULTING LEE-SIDE CYCLONE UNDERGOES OCCLUSION AND LIFTS NWD ACROSS
ND...TRIPLE-POINT LOW WILL TRACK EWD ALONG STRONG WARM FRONT FROM SD
INTO SRN MN AS COLD FRONT SPREADS SEWD INTO THE CNTRL PLAINS THROUGH
THE EVENING. GIVEN MAGNITUDE OF FORCING AND ANTICIPATED SHEAR AND
INSTABILITY ACROSS THE NRN PLAINS AREA...IT IS POSSIBLE THAT PARTS
OF THE REGION MAY BE UPGRADED TO HIGHER SEVERE PROBABILITIES/MDT
RISK IN LATER OUTLOOKS AS MESOSCALE DETAILS BECOME MORE CERTAIN.

LOWER-AMPLITUDE IMPULSES WILL SPREAD ESEWD ATOP LOW-LEVEL BAROCLINIC
ZONE FROM LOWER MI TO THE MID ATLANTIC SEABOARD AND SHOULD PROMOTE
ACTIVE AREAS OF SHOWERS AND TSTMS ACROSS THESE AREAS THROUGH
THURSDAY.

...NRN PLAINS TO UPPER MS VALLEY...
MODELS ARE IN GENERALLY GOOD AGREEMENT THAT STRONG TO LOCALLY
EXTREME INSTABILITY WILL DEVELOP ACROSS CAPPED WARM SECTOR THROUGH
THE AFTERNOON. STRONG FORCING WITH UPPER TROUGH AND ASSOCIATED MID
LEVEL SPEED MAX WILL ACT TO OVERCOME CONVECTIVE INHIBITION WITH
POTENTIALLY EXPLOSIVE TSTM DEVELOPMENT OCCURRING NEAR AND NORTH OF
SURFACE LOW AND WARM FRONT FROM LATE MORNING INTO THE AFTERNOON.
INITIAL ACTIVITY...FROM ND TO SRN MN...MAY BE ROOTED ABOVE CAPPED
BOUNDARY LAYER BUT WILL STILL POSE A THREAT VERY LARGE HAIL AND HIGH
WINDS WITH TIME. STRENGTH OF SHEAR FORECAST ACROSS THE REGION...AND
POTENTIAL FOR ENHANCED ASCENT WITHIN LEFT EXIT REGION OF
INTENSIFYING MID LEVEL JET...SUGGEST WIDESPREAD SEVERE HAIL AND
DAMAGING WIND COULD UNFOLD ACROSS PORTIONS OF SERN ND...ERN SD...AND
SWRN MN THROUGH THE EVENING. TORNADO THREAT MAY BE MODULATED BY
WEAKNESS IN LOWER LEVEL FLOW THAT RESULTS IN GENERALLY LIMITED
SRH...IN ADDITION TO WARM SECTOR CAPPING AND POTENTIALLY HIGHER LFC.
HOWEVER...IF SUPERCELLS CAN BECOME ROOTED IN THE BOUNDARY LAYER AND
PERSIST NEAR THE WARM FRONT...A FEW TORNADOES APPEAR POSSIBLE. PARTS
OF THE REGION MAY REQUIRE UPGRADE TO A MDT RISK IN LATER OUTLOOKS.

...MIDWEST TO NORTHEAST/MID ATLANTIC...
HARD TO TIME LOW-AMPLITUDE SHORT WAVES WILL TRAVERSE LOW LEVEL
FRONTAL ZONE AND ACT TO ENHANCE TSTM DEVELOPMENT AND ORGANIZATION
FROM LOWER MI/OH EWD ACROSS PA/NJ AREAS DURING THE AFTERNOON. WHILE
LAPSE RATES ACROSS THESE AREAS APPEAR SOMEWHAT MARGINAL FOR VIGOROUS
STORM UPDRAFTS...IT IS POSSIBLE THAT MESOSCALE FORCING AND POCKETS
OF STRONGER DESTABILIZATION COULD SUSTAIN STORMS IN AREAS WHERE
SHEAR MAY ALSO SUPPORT SUPERCELLS. POTENTIAL FOR WEAK SURFACE
DEVELOPMENT ACROSS ERN PA TO DELMARVA AREA BY LATER AFTERNOON COULD
FURTHER AID STORM ORGANIZATION WITH A DAMAGING WIND/ISOLATED TORNADO
EVENT POSSIBLE. PARTS OF THIS CORRIDOR MAY BE UPGRADED TO SLGT RISK
IN LATER OUTLOOKS AS FORECAST DETAILS BECOME CLEARER.

..CARBIN.. 08/23/2006