SWODY2
SPC AC 110601
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1201 AM CST THU NOV 11 2010
VALID 121200Z - 131200Z
...NO SVR TSTM AREAS FORECAST...
...SYNOPSIS...
MODELS STILL INDICATE THAT A LARGE UPPER RIDGE WILL CONTINUE TO
BUILD ACROSS THE EASTERN PACIFIC DURING THIS FORECAST PERIOD... WITH
A STRONG HIGH CENTER DEVELOPING 700 MILES OR SO WEST OF THE NORTHERN
CALIFORNIA COAST. WITHIN THE SOUTHERN BRANCH OF THE PREVAILING
DOWNSTREAM SPLIT UPPER FLOW...BROAD TROUGHING IS EXPECTED TO PERSIST
ACROSS MUCH OF THE WESTERN AND CENTRAL UNITED STATES. RIDGING IS
PROGGED TO BEGIN WEAKENING ALONG THE ATLANTIC SEABOARD...BUT A
SIGNIFICANT CLOSED LOW APPEARS LIKELY TO LINGER OVER THE WESTERN
ATLANTIC...EAST OF SOUTH ATLANTIC COASTAL AREAS.
THIS PATTERN IS EXPECTED TO CONTINUE TO INHIBIT BOUNDARY LAYER
MODIFICATION OVER MUCH OF THE CENTRAL/EASTERN GULF OF MEXICO... BUT
A FAIRLY SUBSTANTIVE INFLUX OF MOISTURE IS NOW BEGINNING TO DEVELOP
WITHIN AT LEAST A NARROW TONGUE OFF THE WESTERN GULF OF MEXICO INTO
THE SOUTHERN PLAINS. LOWER 6OS SURFACE DEW POINTS PROBABLY WILL
ADVECT INTO MUCH OF CENTRAL OKLAHOMA TODAY...AND PERSIST INTO
FRIDAY...PRIOR TO THE SOUTHEASTWARD ADVANCEMENT OF A SURFACE FRONT
THROUGH MUCH OF THE SOUTHERN PLAINS BY LATE FRIDAY NIGHT. THE
FRONTAL PASSAGE WILL OCCUR IN RESPONSE TO THE NORTHEASTWARD
PROGRESSION OF A SURFACE WAVE ACROSS THE SOUTH CENTRAL PLAINS INTO
THE MIDDLE MISSISSIPPI VALLEY.
WHILE IT STILL APPEARS THAT THIS WAVE DEVELOPMENT WILL REMAIN
WEAK...CONSIDERABLE VARIABILITY PERSISTS AMONG THE MODELS CONCERNING
THE TIMING OF THIS FEATURE...AND AN ATTENDANT SIGNIFICANT REMNANT
MID-LEVEL SHORT WAVE IMPULSE PROGGED TO ACCELERATE NORTHEAST OF THE
SOUTHERN ROCKIES. THIS COULD HAVE SOME IMPACT ON THE CONVECTIVE
POTENTIAL DURING THIS PERIOD. REGARDLESS...THOUGH...THE RELATIVELY
WEAK NATURE OF THE SURFACE CYCLOGENESIS SUGGESTS THAT THE RISK FOR
SEVERE THUNDERSTORMS WILL BE LIMITED...PARTICULARLY WITH
DESTABILIZATION STILL PROGGED TO REMAIN RATHER WEAK.
...PARTS OF THE SOUTH CENTRAL PLAINS...
DESPITE THE LIKELIHOOD THAT LAPSE RATES WILL NOT STEEPEN
SUFFICIENTLY TO SUPPORT CAPE MUCH MORE THAN 250 TO PERHAPS 500
J/KG...DUE TO THE TENDENCY OF THE MID-LEVEL FORCING TO LAG TO THE
COOL SIDE OF THE SURFACE FRONT...CONCERN STILL EXISTS FOR A WINDOW
OF OPPORTUNITY FOR PRE-FRONTAL BOUNDARY LAYER DESTABILIZATION.
TIMING OF THE UPPER IMPULSE...AND FRONTAL PASSAGE...REGARDLESS OF
WHETHER THE FASTER OR SLOWER MODELS VERIFY...APPEARS FAVORABLE TO
ALLOW FOR THE MOIST BOUNDARY LAYER TO WARM AND WEAKLY DESTABILIZE
ACROSS CENTRAL/EASTERN OKLAHOMA AND PARTS OF ADJACENT SOUTHEAST
KANSAS/SOUTHWEST MISSOURI/NORTHWEST ARKANSAS AND NORTH CENTRAL
TEXAS. IF THIS OCCURS...SHEAR PROFILES WILL PROBABLY BE SUFFICIENT
FOR ORGANIZED STORM DEVELOPMENT...INCLUDING POTENTIAL FOR AN
ISOLATED SUPERCELL OR TWO. ANY SEVERE THREAT SHOULD DIMINISH WITH
FRONTAL PASSAGE THROUGH THE SOUTH CENTRAL PLAINS. STRONGER
MID-LEVEL FORCING LIKELY WILL CONTINUE TO LIFT OFF TO THE
NORTHEAST...AS LOW-LEVEL MOISTURE INFLOW BECOMES CUT OFF.
..KERR.. 11/11/2010
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