[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 031740
SWODY2
SPC AC 031739

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1239 PM CDT MON APR 03 2006

VALID 041200Z - 051200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
HIGHLY AMPLIFIED UPPER AIR PATTERN FCST THROUGH PERIOD...WITH MEAN
TROUGHS OVER E AND W COASTS AND RIDGE ACROSS PLAINS STATES. 
MIDDLE-UPPER LEVEL CYCLONE -- NOW CENTERED OVER SERN LOWER MI -- IS
FCST TO EJECT NEWD AS OPEN WAVE WHILE ANOTHER MIDDLE-UPPER LEVEL LOW
OVER NRN ONT DIGS SEWD ACROSS GREAT LAKES AND NY.  ASSOCIATED SFC
COLD FRONT WILL SWEEP OFFSHORE MOST OF ATLANTIC COAST FROM MID
ATLANTIC STATES SWD TO CENTRAL/NRN FL. WRN REMNANT OF THIS FRONT
WILL STALL LATE DAY-1 OVER NRN GULF AND S TX...THEN BECOME DIFFUSE
AND RETURN NWD OVER SRN/CENTRAL TX DAY-2.

MEANWHILE...DEEP UPPER LOW -- NOW EVIDENT IN MOISTURE CHANNEL
IMAGERY AROUND 36N134W -- IS FCST TO PIVOT EWD THROUGH DAY-2 WITH
STRONG SHORTWAVE TROUGH MOVING ONSHORE SRN CA AROUND 5/06Z.  BROAD
PLUME OF WAA AND MIDLEVEL MOIST ADVECTION WILL OVERSPREAD MUCH OF
WRN CONUS AHEAD OF THIS SYSTEM.

NET RESULT WILL BE SEVERAL AREAS OF MRGL AND OR CONDITIONAL SEVERE
POTENTIAL.

...EARLY MORNING -- TX/SERN NM...
MRGL/CONDITIONAL HAIL PROBABILITIES EXIST OVER THIS REGION FOR FIRST
FEW HOURS OF PERIOD...AMIDST EXTENSION OF LATE DAY-1 WAA/MOISTURE
RETURN REGIME. ELEVATED BUOYANCY IS FCST TO BE SMALL -- GENERALLY
AOB 500 J/KG MOST AREAS.  HOWEVER...ANY SUSTAINED CONVECTION WILL
HAVE POTENTIAL FOR HAIL GIVEN STRONG VEERING AND SPEED SHEAR WITH
HEIGHT THROUGH CONVECTIVE COLUMN...WHICH SHOULD BE ROOTED IN 800-850
MB LAYER BASED ON FCST SOUNDINGS.  ACTIVITY SHOULD DIMINISH DURING
LATE MORNING AS LLJ WEAKENS.

...AFTERNOON/EVENING -- CA...
CONDITIONAL THREAT FOR SEVERE EXISTS BOTH OVER CENTRAL VALLEY AND
COASTAL AREAS...AMIDST WEAK CINH AND AT LEST MRGL MUCAPES OF 100-400
J/KG.  LOW LEVEL MOIST ADVECTION AND STEEPENING LAPSE RATES ALOFT
SHOULD SUPPORT SCATTERED TSTMS...PARTICULARLY DURING AFTERNOON WHERE
BREAKS IN CLOUD COVER CAN ALLOW POCKETS OF DIABATIC SFC HEATING. 
VERTICAL SHEAR PROFILES ACROSS PORTIONS COASTAL SRN CA ARE FCST TO
BE LARGE -- CHARACTERIZED BY STRONG VEERING WITH HEIGHT AND
STRENGTHENING MIDLEVEL FLOW GRADIENTS AHEAD OF SHORTWAVE TROUGH. 
BASIC PATTERN RESEMBLES THAT OF SOME L.A. BASIN SUPERCELL CASES AND
THIS AREA MAY REQUIRE ENHANCED PROBABILITIES ONCE TIMING/STRENGTH OF
FEATURES ALOFT BECOMES BETTER ESTABLISHED.  INLAND...DEEP-LAYER
WINDS WILL BE MORE UNIDIRECTIONAL WITH STRONG MERIDIONAL
COMPONENT...THOUGH OROGRAPHICALLY FORCED BACKING SHOULD ENHANCED
SHEAR OVER PORTIONS CENTRAL VALLEY.

...AFTERNOON/EVENING -- GREAT BASIN...
WIDELY SCATTERED TSTMS ARE EXPECTED TO DEVELOP OVER PORTIONS BASIN
-AND-RANGE REGION -- SHIFTING/EVOLVING NWD TOWARD SNAKE RIVER
VALLEY.  MAIN CONCERN IS ISOLATED GUSTS NEAR SEVERE LEVELS.
MAIN LIMITING FACTOR IS WEAK BOUNDARY LAYER MOISTURE...WHICH WILL
LIMIT MLCAPES TO BELOW 250 J/KG MOST AREAS.  STRONG VERTICAL MIXING
IS LIKELY DURING AFTERNOON...WEAKENING CINH AND RESULTING IN
POTENTIAL FOR TSTM FORMATION.  STRONG MIDLEVEL FLOW WILL SUPPORT
40-60 KT DEEP-LAYER SHEAR IN SUPPORT OF POTENTIAL FOR STRONG-SEVERE
GUSTS FROM MOST VIGOROUS CONVECTION.

...LATE OVERNIGHT -- OZARKS TO E-CENTRAL PLAINS...
SCATTERED TSTMS SHOULD DEVELOP MAINLY AFTER 5/06Z IN THIS
REGION...WITH ISOLATED HAIL POSSIBLE.  LOW LEVEL WAA/MOIST ADVECTION
REGIME WILL INTENSIFY THROUGH PERIOD...CULMINATING IN RETURN OF
FAVORABLE INCREASING LOW LEVEL MOISTURE AFTER DARK FROM MUCH OF AR
NWWD OVER PORTIONS NERN OK...ERN KS AND WRN MO.  ETA/SPECTRAL FCSTS
OF CONVECTIVE DEVELOPMENT OVER THIS REGION APPEAR REASONABLE BASED
ON UPSTREAM MOISTURE PROFILES EVIDENT ACROSS S TX AND WRN GULF. 
EXPECT ISENTROPIC LIFT OF PARCELS TO LFC WITH ELEVATED MUCAPES
INCREASING TO AROUND 250-500 J/KG.  35-40 KT EFFECTIVE SHEARS IN
FCST SOUNDINGS SUGGEST SOME POTENTIAL FOR TSTMS TO BECOME ORGANIZED
AND PRODUCE HAIL.

..EDWARDS.. 04/03/2006