[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 181252
SWODY1
SPC AC 181251

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0651 AM CST SAT MAR 18 2006

VALID 181300Z - 191200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER MUCH OF W TX AND ERN NM...

...SYNOPSIS...
MINIMAL LARGE SCALE CHANGE EXPECTED OVER THE LWR 48 THIS PERIOD AS
DEEP VORTEX LINGERS OVER THE GULF OF ST LAWRENCE AND WRN STATES
TROUGH PROGRESSES SLOWLY E INTO THE GRT BASIN. VORT MAX IN BASE OF
WRN TROUGH...NOW OVER SRN CA...SHOULD LIFT NE INTO WRN CO BY EARLY
SUNDAY AS ADDITIONAL SPEED MAXIMA DROP S FROM NV/CA INTO NRN BAJA. 
SHORTWAVE RIDGING WILL CONTINUE OVER THE SRN PLNS THROUGH MUCH OF
THE DAY...ALTHOUGH HEIGHTS WILL BEGIN TO FALL FROM W TO E LATER
TODAY AND TONIGHT AS WRN TROUGH EDGES EWD.

AT THE SURFACE...SHALLOW FRONT NOW EXTENDING ESE FROM N OF THE BIG
BEND REGION SHOULD DRIFT SLOWLY NE THROUGH THE PERIOD AS UPR FLOW
SLIGHTLY BACKS AND STRENGTHENS DOWNSTREAM FROM APPROACHING TROUGH.

...W TX/SE NM...
SLIGHTLY ELEVATED TSTMS EXPECTED TO PERSIST THROUGH AT LEAST MIDDAY 
IN ZONE OF LOW LVL WARM ADVECTION ACROSS W TX. THIS ACTIVITY SHOULD
TEND TO SPREAD N/NE WITH TIME ALONG 30-40 KT SLY LLJ.  THE STORMS
MAY POSE AN OCCASIONAL THREAT FOR SEVERE HAIL GIVEN QUALITY OF
ELEVATED MOISTURE INFLOW /MIXING RATIOS AOA 13 G PER KG IN UPSTREAM
LOW LVL ENVIRONMENT NEAR KDRT/.

GIVEN AT LEAST MODEST SURFACE HEATING...SURFACE-BASED STORM
DEVELOPMENT IS POSSIBLE BY MID TO LATE AFTERNOON ALONG LEE
TROUGH/DRYLINE THAT SHOULD FORM OVER SW TX INTO SERN NM.  A FEW
SURFACE-BASED STORMS MAY ALSO DEVELOP FARTHER E/SE ALONG WARM FRONT.
 THE MAIN SEVERE THREAT WITH ALL OF THE ACTIVITY SHOULD BE LARGE
HAIL AS DEEP SWLY SHEAR AOA 50 KTS WILL SUPPORT SUSTAINED
SUPERCELLS.  HOWEVER...SEASONABLY RICH BOUNDARY LAYER MOISTURE
INFLOW AND LARGE DIRECTIONAL COMPONENT TO LOW LEVEL SHEAR /ESE
SURFACE WINDS VEERING TO SLY AT 850 MB/ SUGGEST A POTENTIAL FOR
TORNADOES ALONG WARM FRONT.  THIS THREAT SHOULD BE MAXIMIZED WITH
ANY DISCRETE CELLS THAT REMAIN SURFACE-BASED AND/OR MOVE ESELY ALONG
THE FRONT.  CAPPING ASSOCIATED WITH AFOREMENTIONED SHORTWAVE RIDGE
SHOULD LIMIT OVERALL COVERAGE OF SURFACE-BASED STORMS.

CONTINUED EWD ADVANCE OF WRN U.S. TROUGH SHOULD STRENGTHEN LLJ AND
ASSOCIATED ELEVATED MOISTURE TRANSPORT...AND LOWER HEIGHTS... ACROSS
TX AND OK TONIGHT THROUGH EARLY SUNDAY.  THIS SHOULD CREATE AN
INCREASINGLY FAVORABLE ENVIRONMENT FOR ELEVATED TSTMS AS MUCAPE
RISES TO AOA 1500 J/KG NWD INTO OK.  WITH CLOUD LAYER SHEAR
INCREASING TO AROUND 50-60 KT...ELEVATED SUPERCELLS WITH HAIL APPEAR
LIKELY.  FARTHER S...POTENTIAL WILL ALSO EXIST FOR POSSIBLE
SURFACE-BASED STORMS INVOF WARM FRONT ACROSS CNTRL TEXAS.

...NRN NM AND S CNTRL CO...
SURFACE HEATING MAY INITIATE ISOLATED TO WIDELY SCATTERED TSTMS OVER
THE HIGHER TERRAIN ALONG AND JUST E OF SANGRE DE CRISTOS MTNS...AS
WELL AS OVER WRN RATON MESA AREA OF NE NM.  THIS ACTIVITY MAY POSE A
THREAT FOR HAIL OR DAMAGING GUSTS...ALTHOUGH BOTH STORM DURATION AND
COVERAGE ARE QUESTIONABLE GIVEN LIMITED BOUNDARY LAYER MOISTURE. 
SEVERE THREAT WILL BE FOSTERED BY STEEP LOW-MIDLEVEL LAPSE RATES
/AROUND 8 DEG C PER KM/ AND 60-70 KT DEEP-LAYER SHEAR.

..CORFIDI.. 03/18/2006