[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 051239
SWODY1
SPC AC 051238

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0738 AM CDT FRI MAY 05 2006

VALID 051300Z - 061200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM NM TO THE LOWER MS RIVER
VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE
SOUTHEAST...

...SRN HIGH PLAINS ACROSS MUCH OF TX...
SURFACE PATTERN HAS BEEN MUDDLED ACROSS THIS AREA BY EXTENSIVE
CONVECTION/MCS ACTIVITY OVER THE PAST FEW NIGHTS.  PRIMARY SURFACE
COLD FRONT APPEARS TO EXTEND FROM THE ARKLATEX REGION W-SWWD INTO
SERN NM AT 12Z...WITH MARINE AIR /70+F DEW POINTS/ REMAINING
CONFINED TO DEEP SOUTH TX AND JUST OFF THE MIDDLE AND UPPER TX
COAST. WEAK SURFACE LOW NOW EVIDENT OVER FAR SERN NM WILL BECOME
BETTER DEFINED ALONG INTERSECTION OF COLD FRONT AND DRY LINE THROUGH
THE DAY AHEAD OF PROMINENT MID/UPPER LEVEL TROUGH NOW MOVING ACROSS
THE LOWER CO RIVER VALLEY.  ASSOCIATED 40-50 KT WLY MID LEVEL JET
WILL OVERSPREAD MUCH OF THE SRN HIGH PLAINS THROUGH THE DAY...AS
LARGE SCALE PRESSURE FALLS INCREASE SSELY LOW LEVEL FLOW.  THIS WILL
PROVIDE A VERY FAVORABLE SETUP FOR SUPERCELLS FROM PORTIONS OF
CENTRAL/SERN NM ACROSS MUCH OF WRN TX BY THE MID AFTERNOON WITH
EFFECTIVE BULK SHEAR IN EXCESS OF 50 KT...DEPENDING UPON QUALITY OF
BOUNDARY LAYER AIR MASS.  WEDGE OF MID 60F SURFACE DEW POINTS
REMAINS IN PLACE FROM THE TX BIG BEND ACROSS THE TRANS PECOS EARLY
THIS MORNING.  INCREASING SELY SURFACE WINDS AND LARGE SCALE
PRESSURE FALLS WILL LIKELY LIFT WARM FRONT/RICHER GULF MOISTURE NWD
ALONG AND WEST OF THE HILL COUNTRY THROUGH THE DAY...WITH NARROW
WEDGE OF LOW-MID 50F SURFACE DEW POINTS EXTENDING INTO PORTIONS OF
CENTRAL NM LATER TODAY.  THIS WILL SUPPORT AN AXIS OF MODERATE TO
STRONG INSTABILITY FROM SRN/CENTRAL TX NWWD INTO THE SERN NM BY THE
MID TO LATE AFTERNOON.

INCREASING LARGE SCALE ASCENT AND CONVERGENCE/UPSLOPE WILL BREAK CAP
AND INITIATE SEVERE THUNDERSTORMS NEAR HIGHER TERRAIN AND TRIPLE
POINT/DRY LINE OVER SERN NM/SWRN TX BY 22Z.  SUPERCELLS WILL BE
LIKELY WITHIN THIS ZONE WITH ATTENDANT THREATS OF VERY LARGE HAIL
AND PERHAPS A FEW TORNADOES.  TORNADO THREAT MAY INCREASE INTO THE
EARLY EVENING AS ACTIVITY MOVES INTO RICHER BOUNDARY LAYER MOISTURE
AND STRONGER LOW LEVEL SHEAR ACROSS THE EDWARDS PLATEAU REGION. 
EXPECT ACTIVITY WILL INTENSIFY INTO A SEVERE MCS AND POSSIBLY EVOLVE
INTO A BOW ECHO WITH INCREASED WIND DAMAGE THREAT AS ACTIVITY
SPREADS EWD ALONG INSTABILITY GRADIENT/SURFACE BOUNDARY WITH
ATTENDANT SEVERE REACHING THE TX COASTAL PLAIN OVERNIGHT.

...LOWER MS RIVER VALLEY INTO THE CENTRAL GULF COAST...
MCV/VORT MAX ASSOCIATED WITH MCS WHICH TRAVERSED NRN TX OVERNIGHT
WAS NOW OVER NERN TX.  AHEAD OF THIS FEATURE...AXIS OF RICH GULF
MOISTURE IS PERSISTING ALONG THE SABINE RIVER/CENTRAL LA WHERE 12Z
LCH SOUNDING INDICATES VERY STEEP LAPSE ARE IN PLACE.  LOW LEVEL
WINDS AND SUBSEQUENT LOW LEVEL SHEAR REMAIN RATHER WEAK. 
HOWEVER...20-30 KT EFFECTIVE SHEAR SHOULD SUPPORT ORGANIZED
MULTICELL CLUSTERS/LINES WITH THREATS OF LARGE HAIL DAMAGING WINDS
AS STORMS INCREASE AND DEVELOP SEWD TODAY.  EWD EXTENT OF STRONGER
STORMS WILL BE LIMITED BY CONVECTIVELY-STABILIZED AIR NOW IN PLACE
OVER CENTRAL MS.

...SOUTHEAST...
MODELS IN AGREEMENT IN MOVING VORT MAX/SHORTWAVE TROUGH EWD OUT OF
AL AND INTO GA/SC TODAY.  AHEAD OF THIS FEATURE ABUNDANT HEATING
WILL DEVELOP...ESPECIALLY INTO ERN GA/SC...WHERE LOW LEVEL LAPSE
RATES BECOME QUITE STEEP.  OVERALL MLCAPES WILL REMAIN MARGINAL WITH
SURFACE DEW POINTS IN THE LOWER 60S.  HOWEVER...MLCAPE WILL BE
SUFFICIENT FOR SCATTERED THUNDERSTORMS AS LARGE SCALE ASCENT SPREADS
EWD TOWARDS THE CAROLINAS TODAY.  GIVEN MODEST WLY FLOW ALOFT AND
STEEP LOW LEVEL LAPSE RATES...ISOLATED WIND DAMAGE AND HAIL ARE
EXPECTED TO ACCOMPANY STRONGER CORES/LINES INTO THE EARLY EVENING.

..EVANS.. 05/05/2006