[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 150604
SWODY2
SPC AC 150603

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0103 AM CDT TUE AUG 15 2006

VALID 161200Z - 171200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF ERN MT AND ND...

...SYNOPSIS...
NWRN U.S. UPPER TROUGH SHOULD EDGE EAST OVER THE NRN GREAT BASIN AND
NRN ROCKIES DURING WEDNESDAY. A BELT OF MODEST /30-40KT/ WSWLY MID
LEVEL FLOW WILL EXTEND FROM THE BASE OF THE TROUGH...ACROSS THE NRN
PLAINS...AND THEN THROUGH A SHORT WAVE RIDGE AXIS FROM THE UPPER MS
VALLEY TO GREAT LAKES. LOWER-AMPLITUDE DISTURBANCES ARE FORECAST TO
EMANATE FROM THE LARGER SCALE TROUGH WITH VERY WEAK HEIGHT FALLS
SPREADING ACROSS THE NRN PLAINS THROUGH WEDNESDAY NIGHT. IT IS ALSO
POSSIBLE THAT A MORE SUBTLE SHORT WAVE IMPULSE...PERHAPS
CONVECTIVELY ENHANCED...MAY EMERGE FROM SUBTROPICAL STREAM ACROSS
THE SRN PLAINS AND AID LARGE SCALE BACKGROUND ASCENT OVER THE SRN
AND CNTRL HIGH PLAINS...EWD TO THE MO VALLEY.

MODELS CONTINUE TO INDICATE SUBTROPICAL GYRE WILL DRIFT INTO THE
GULF WHILE A SMALLER SCALE LOW FORMS NEAR THE SOUTHEAST U.S. COAST.
BOTH THESE FEATURES WILL BE TO THE SOUTH AND EAST OF A
DECAYING SYNOPTIC FRONTAL BOUNDARY SITUATED FROM THE CAROLINAS TO
THE DEEP SOUTH.

...NRN PLAINS...
LOW LEVEL SLY FLOW AND MOISTURE TRANSPORT WILL STRENGTHEN ACROSS THE
CNTRL AND NRN PLAINS THIS PERIOD IN RESPONSE TO ISALLOBARIC AND
DIABATIC FORCING RESULTING FROM APPROACH OF ROCKIES TROUGH AND
DIURNAL HEATING. IT IS LIKELY THAT A STRONG EML/CAP WILL ACT TO
INHIBIT CONVECTIVE DEVELOPMENT ACROSS MUCH OF THE WARM SECTOR BUT
AIR MASS ACROSS THE REGION SHOULD BECOME MODERATELY UNSTABLE GIVEN
DEWPOINTS IN THE 60S AND TEMPERATURES IN THE UPPER 80S AND LOWER
90S. GIVEN STRONG CAP AND ONLY MARGINAL LARGE SCALE SUPPORT FOR
ASCENT FROM LOW AMPLITUDE MID LEVEL IMPULSE...LATE DAY STORM
INITIATION APPEARS MOST LIKELY NEAR AND NORTH OF WSW-ENE ORIENTED
DEEP-LAYER BAROCLINIC ZONE...FROM MT INTO NCNTRL ND. ADDITIONAL TSTM
ACTIVITY...IN LOWER CAPE ENVIRONMENT...APPEARS LIKELY FROM ERN ORE
ACROSS PARTS OF ID AND WRN MT...CLOSER TO THE STRONGER FORCING AND
AIDED BY OROGRAPHIC FORCING. ISOLATED HIGH-BASED CONVECTION MAY ALSO
FORM WHERE CAP CAN BE LOCALLY OVERCOME NEAR LEE/THERMAL TROUGH OR
DRYLINE FROM WRN/CNTRL SD...SSWWD INTO NEB.

OVER ERN MT AND ND...INSTABILITY FLOWING FROM CAPPED ENVIRONMENT
INTO FRONTAL AND POST-FRONTAL CONVECTION WILL LIKELY FUEL A FEW
INTENSE STORM UPDRAFTS WHERE DEEP LAYER SHEAR WILL BE MORE THAN
SUFFICIENT FOR CELL ROTATION AND HAIL PRODUCTION. IT IS POSSIBLE
THAT OUTFLOW FROM THIS ACTIVITY WILL ENHANCE MESOSCALE FORCING ALONG
THE LOW LEVEL BOUNDARY TO PROMOTE ADDITIONAL SURFACE-BASED STORMS
OVER SRN/ERN SECTIONS OF ND. HAIL AND WIND THREAT MAY EVOLVE FROM
THIS CONVECTION AND SPREAD EAST TOWARD PARTS OF WRN MN DURING THE
NIGHT.

...CNTRL PLAINS TO MO VALLEY...
WEAK QG-FORCING ATOP LEE TROUGH AND/OR RESIDUAL FRONTAL BOUNDARY
BISECTING KS SHOULD PROMOTE AFTERNOON AND EVENING TSTM DEVELOPMENT
OVER THE PLAINS. GENERALLY WEAK DEEP-LAYER SHEAR AND LAPSE RATES IN
WARM MOIST/MOIST ENVIRONMENT SUGGEST ONLY ISOLATED AND MARGINAL
HAIL/WIND POTENTIAL. HOWEVER...LOCALLY ENHANCED LOW LEVEL SHEAR AND
INSTABILITY NEAR THE RESIDUAL FRONT MIGHT SUPPORT A SUPERCELL OR TWO
FROM CNTRL KS NWD TO SRN NEB. IT IS POSSIBLE THAT A FEW STRONG TSTMS
MAY PERSIST IN WAA REGIME ACROSS KS/NEB INTO THE NIGHT. THIS
ACTIVITY MAY CONGEAL INTO A SMALL MCS AND BE SUSTAINED ACROSS THE MO
VALLEY AS NOCTURNAL LLJ INTENSIFIES OVERNIGHT.

..CARBIN.. 08/15/2006