SWODY1
SPC AC 170047
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0747 PM CDT WED APR 16 2008
VALID 170100Z - 171200Z
..THERE IS A SLGT RISK OF SVR TSTMS PORTIONS SWRN TO CENTRAL KS...
..SYNOPSIS...
MIDDLE-UPPER LEVEL SYNOPTIC PATTERN CONTINUES TO FEATURE BROAD
CYCLONE OFFSHORE ATLANTIC COAST...POSITIVELY TILTED RIDGE FROM GULF
COAST TO ST LAWRENCE VALLEY...AND PRONOUNCED TROUGHING FROM HUDSON
BAY ACROSS 4-CORNERS REGION. ANCHORING SHORTWAVE -- INITIALLY
EVIDENT IN MOISTURE CHANNEL IMAGERY OVER UT -- IS FCST TO DIG SEWD
ACROSS 4-CORNERS AREA TO SAN JUAN MOUNTAINS OF NWRN NM AND SWRN CO
OVERNIGHT. FOREGOING HEIGHT FALLS AND ENHANCED SWLY FLOW ALOFT WILL
SHIFT SLOWLY EWD ACROSS MORE OF CENTRAL/SRN GREAT PLAINS...COMBINING
WITH NOCTURNAL BOUNDARY LAYER DECOUPLING IN WARM SECTOR TO SUPPORT
STG LLJ...LOW LEVEL WAA...AND ACCOMPANYING NWD MOTION OF PARTIALLY
MODIFIED RETURN FLOW AIR PLUME.
AT SFC...PREVIOUSLY QUASISTATIONARY FRONT WAS ANALYZED AT 00Z FROM
NEAR SERN CORNER NEB SWWD ACROSS HUT...GAG...AND NRN TX PANHANDLE.
SEGMENTS OF THIS FRONT BETWEEN HUT-AMA HAVE RETREATED NWWD SLIGHTLY
AS WARM FRONT DURING PAST 1-2 HOURS...AS ATTACHED LOW OVER NWRN
PANHANDLE/NERN NM BEGINS TO MOVE EWD ALONG FRONT. LOW IS FCST TO
MOVE ACROSS NRN PANHANDLE THROUGH APPROXIMATELY 06Z...THEN EJECT
NEWD ACROSS NWRN OK DURING ENSUING 6 HOURS. AS THIS OCCURS...KS
PORTION OF FRONT MAY CONTINUE TO DRIFT NWWD...WHILE TRAILING PORTION
WILL MOVE SWD AS COLD FRONT ACROSS CENTRAL/WRN TX PANHANDLE AND
S-CENTRAL NM. AT 00Z...SFC DRYLINE INTERSECTED FRONT OVER HEMPHILL
COUNTY TX AND WAS RETREATING WWD ACROSS ERN PANHANDLE. PRIND
DRYLINE WILL BECOME QUASISTATIONARY AGAIN BY AROUND 06Z.
..S-CENTRAL PLAINS...
SEVERAL CB DEVELOPED BRIEFLY THEN DISSIPATED INVOF COLD
FRONT-DRYLINE INTERSECTION OVER NWRN OK...DURING PAST 1-2 HOURS.
ALTHOUGH ADDITIONAL SFC-BASED CONVECTIVE INITIATION REMAINS POSSIBLE
IN THIS AREA BEFORE SUNSET...IT BECOMES INCREASINGLY LESS PROBABLE
WITH TIME BECAUSE OF COMBINATION OF SHADOWING FROM CLOUD COVER...AND
COMBINED REDUCTION OF SBCAPE AND INCREASING SBCINH RESULTING FROM
DIABATIC/RADIATIONAL COOLING.
CONVECTIVE EMPHASIS SOON WILL SHIFT TOWARD NOCTURNAL DEVELOPMENT
SOMEWHAT FARTHER N...RELATED TO STRENGTHENING LLJ AND MOISTENING
ABOVE BOUNDARY LAYER. CONTINUED ISENTROPIC ASCENT AND SLOW
MOISTENING WITHIN 700-850 MB LAYER -- PARTICULARLY OVER SWRN THROUGH
CENTRAL KS -- SHOULD RESULT IN INCREASING ASCENT TO LFC AND
STRENGTHENING BUOYANCY THROUGH TONIGHT. EXPECT 500-800 J/KG
ELEVATED MUCAPE OVER OUTLOOK AREA...CONCURRENT WITH 50-60 KT
EFFECTIVE BULK SHEAR MAGNITUDES. THIS SHOULD SUPPORT POTENTIAL FOR
A FEW ORGANIZED TSTMS PRODUCING LARGE HAIL. IN ADDITION...STG-SVR
GUSTS CANNOT BE RULED OUT INVOF FRONT...DESPITE SHALLOW/STABLE LAYER
NEAR SFC...BECAUSE OF SUBCLOUD DRYING LOCATED BETWEEN THAT STABLE
LAYER AND AFOREMENTIONED MOIST PROFILE.
.EDWARDS.. 04/17/2008
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