Sunday, December 6, 2009

DAY3SVR: Nws Storm Prediction Center Norman Ok

ACUS03 KWNS 060812
SWODY3
SPC AC 060811

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0211 AM CST SUN DEC 06 2009

VALID 081200Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN TX INTO THE CNTRL
GULF STATES...

...SYNOPSIS...

CONSIDERABLE STRENGTHENING/BROADENING OF MID/HIGH-LEVEL JET STREAKS
IS FORECAST FROM THE SRN ROCKIES EWD INTO THE LOWER MS/TN VALLEYS
DURING THE DAY THREE PERIOD. THIS INCREASING FLOW FIELD WILL OCCUR
ON SRN FRINGE OF MIDLEVEL TROUGH WHICH WILL BECOME NEGATIVELY TILTED
WHILE TRANSLATING ENEWD FROM THE SRN ROCKIES INTO MID MS VALLEY. AT
THE SURFACE...PRIMARY CYCLONE WILL UNDERGO SIGNIFICANT DEEPENING
THROUGH THE PERIOD WHILE DEVELOPING FROM NEAR OR E OF THE FOUR
CORNERS INTO THE MID MS VALLEY. ACCOMPANYING COLD FRONT WILL PUSH
EWD THROUGH THE SRN PLAINS INTO MIDDLE/LOWER MS VALLEYS WHILE
ATTENDANT WARM FRONT LIFTS NWD THROUGH THE GULF COAST AND SERN
ATLANTIC STATES.

...LOWER SABINE RIVER VALLEY INTO CNTRL GULF STATES...

LOWER TROPOSPHERIC MASS RESPONSE TO OVERALL DEEPENING OF SYNOPTIC
SYSTEM WILL SUPPORT THE RAPID NWD/NEWD TRANSPORT OF AN INCREASINGLY
MOIST AIR MASS IN ADVANCE OF SURFACE LOW AND COLD FRONT.
HOWEVER...WEAK LAPSE RATES WILL OFFSET THIS MOISTENING PROCESS WITH
AFTERNOON WARM SECTOR BECOMING ONLY MARGINALLY UNSTABLE.

THE CORRIDOR OF MORE SIGNIFICANT HEIGHT FALLS/DYNAMIC FORCING FOR
ASCENT IS EXPECTED TO REMAIN N OF REGION IN CONJUNCTION WITH
MIDLEVEL TROUGH. BUT...PERSISTENT LOW-LEVEL WAA AND BOUNDARY LAYER
MOISTENING SHOULD CONTRIBUTE TO AN INCREASE IN SURFACE-BASED STORM
DEVELOPMENT TUESDAY WITHIN EXPANDING AND WEAKLY CAPPED WARM SECTOR.
FORECAST HODOGRAPHS INDICATE STRONG LOW AND DEEP-LAYER
SHEAR...SUPPORTIVE OF SUPERCELLS AND BOWING STRUCTURES WITH AN
ASSOCIATED THREAT FOR TORNADOES AND DAMAGING WINDS.

THE POTENTIAL FOR SEVERE STORMS WILL LIKELY CONTINUE ACROSS THE
CNTRL GULF STATES TUESDAY NIGHT. BUT...THE MAGNITUDE AND EWD EXTENT
OF THIS THREAT REMAIN UNCERTAIN OWING TO THE VERY WEAK INSTABILITY
FORECAST.

...ERN CAROLINAS...

EWD MIGRATION/DEVELOPMENT OF SLY LLJ WILL HASTEN THE INFLUX OF
MOISTURE OFF THE WRN ATLANTIC...AND EVENTUALLY ERN GULF OF MEXICO
BASIN IN WAKE OF RETREATING WEDGE FRONT. THE THREAT FOR ISOLATED
SEVERE STORMS IS EXPECTED TO INCREASE LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING AS INCREASED LOW-LEVEL WAA ACTS ON
MOISTENING/DESTABILIZING ENVIRONMENT. CURRENTLY...IT APPEARS THAT
THE MARGINAL CONVECTIVE INSTABILITY WILL LIMIT THE POTENTIAL FOR A
MORE ROBUST SEVERE THREAT. THEREFORE...ONLY LOW PROBABILITIES WILL
BE INCLUDED IN THIS FORECAST.

..MEAD.. 12/06/2009

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.

No comments: