[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 040622
SWODY2
SPC AC 040621

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0121 AM CDT TUE APR 04 2006

VALID 051200Z - 061200Z

...THERE IS A SLGT RISK OF SVR TSTMS LATE WEDNESDAY/EARLY THURSDAY
ACROSS SD AND NERN NEB...

...SYNOPSIS...
LARGE AND COMPLEX UPPER TROUGH OFF THE WEST COAST IS FORECAST TO
ACCELERATE INLAND AND CROSS THE GREAT BASIN/INTERMOUNTAIN REGIONS
THROUGH THE DAY 1 PERIOD BEFORE A LARGE AREA OF STRONG HEIGHT FALLS
ASSOCIATED WITH THIS DISTURBANCE SPREADS OVER GREAT PLAINS WEDNESDAY
NIGHT THROUGH THURSDAY. MEANWHILE...A STRONG UPPER RIDGE CURRENTLY
ACROSS THE PLAINS WILL SHIFT EAST TO THE MS VALLEY AND GRADUALLY
DEAMPLIFY. DOWNSTREAM FROM THE CNTRL U.S. UPPER RIDGE...A DEEP POLAR
VORTEX WILL FORM OVER THE NORTHEAST AND DRIFT EWD.

HIGH AMPLITUDE FLOW REGIME ACROSS THE WRN AND CNTRL STATES WILL
ALLOW DEEP LAYER SLY/SWLY WINDS TO PERSIST AND STRENGTHEN AHEAD OF
THE WRN TROUGH THROUGH WEDNESDAY. SUBSIDENCE BENEATH THE UPPER RIDGE
AND STEADY WARMING ACROSS THE HIGH PLAINS THROUGH WEDNESDAY WILL
RESULT IN AN EXTENSIVE ELEVATED MIXED LAYER AIRMASS DEVELOPING FROM
THE SOUTHERN ROCKIES/HIGH PLAINS NWD TO THE DAKOTAS. LEE
CYCLOGENESIS IS EXPECTED TO COMMENCE ACROSS CO/WY/MT BY WEDNESDAY
EVENING AS STRONG DYNAMIC FORCING AHEAD OF THE UPPER TROUGH MOVES
NEWD OVER THESE AREAS. ASSOCIATED WARM FRONT SHOULD FORM AND LIFT
NWD ACROSS THE NRN PLAINS OVERNIGHT AS STRONG PACIFIC COLD FRONT
SPREADS EAST FROM THE ROCKIES AND INTO THE HIGH PLAINS THROUGH
THURSDAY MORNING.

...HIGH PLAINS /WRN TX TO WRN NEB/ THROUGH WEDNESDAY EVENING...
DESPITE STRONG LOW LEVEL SLY FLOW DEVELOPING ACROSS THE PLAINS
THROUGH THE PERIOD...LATEST GUIDANCE CONTINUES TO SUGGEST THAT
MOISTURE RETURN ACROSS THE PLAINS WILL BE LESS THAN ROBUST INTO THE
DAY 2 PERIOD. MODELS APPEAR TO SUGGEST THAT EITHER A POCKET...OR
NARROW AXIS...OF GREATER LOW LEVEL MOISTURE /850MB DEWPOINTS AROUND
10C/ WILL ADVECT NWD AND THEN NEWD FROM LOWER RIO GRANDE
VALLEY...ACROSS THE SRN PLAINS...TO THE MO RIVER VALLEY THROUGH THE
PERIOD. WEAK HEIGHT FALLS COUPLED WITH DEEP MIXING/HEATING AND
CONFLUENT FLOW NEAR DRYLINE/LEE TROUGH...FROM WEST TX TO THE NEB
PANHANDLE...MAY PROMOTE HIGH-BASED TSTM DEVELOPMENT BY WEDNESDAY
EVENING. EXPECT THE BULK OF THIS ACTIVITY TO STRUGGLE TO PERSIST
GIVEN POTENTIAL FOR STRONG INHIBITION... ESPECIALLY FROM KS/NEB AREA
SWD AFTER DARK. HOWEVER...A FEW HIGH-BASED SUPERCELLS COULD RESULT
IN A COUPLE OF ISOLATED HAIL/WIND EVENTS.

...NRN PLAINS...
CONDITIONS FOR VIGOROUS DEEP CONVECTION SHOULD IMPROVE THROUGH LATE
WEDNESDAY EVENING FROM ERN WY/MT EWD ACROSS NEB AND SD. STRONG
DYNAMIC FORCING ASSOCIATED WITH INCREASINGLY DIFFLUENT FLOW ALOFT
WILL SPREAD NEWD ATOP INTENSIFYING ZONE OF WARM AIR ADVECTION OVER
THE NRN PLAINS. SCATTERED TSTMS WITH A MARGINAL THREAT OF HAIL AND
STRONG WINDS MAY FIRST INITIATE ACROSS THE HIGHER TERRAIN OF WY/MT
WHERE INHIBITION AND CAPE WILL BE WEAKER. WHILE WARM SECTOR SURFACE
PARCELS WILL LIKELY REMAIN CAPPED BY STRONG ELEVATED MIXED LAYER
THROUGH THE EVENING...HIGH-BASED STORMS SHOULD DEVELOP EAST AND
PERSIST AS MOISTENING...LIFT...AND DESTABILIZATION ALL INCREASE
WITHIN THE WARM FRONTAL ZONE. LATEST GUIDANCE WOULD SUPPORT A SEVERE
MCS MOVING EAST ACROSS SD/NERN NEB THROUGH DAYBREAK THURSDAY WITH
THE PRIMARY HAZARD BEING LARGE HAIL.

..CARBIN.. 04/04/2006