Post by SKYSUMMIT on Dec 7, 2008 15:32:21 GMT -6
This thread is for discussing he possible severe weather for Tuesday, December 9th.
Current SPC Outlook is a Slight Risk.
...CENTRAL GULF COAST/LOWER MISSISSIPPI VALLEY...
THE EVOLVING UPPER PATTERN IS EXPECTED TO SUPPORT THE CONTINUATION
OF A RETURN FLOW OF MOISTURE OFF THE WESTERN GULF OF MEXICO THROUGH
THE LOWER MISSISSIPPI VALLEY TUESDAY/TUESDAY NIGHT. LAPSE RATES
ACROSS THIS REGION LIKELY WILL BE WEAK...AND CLOUD COVER COULD BE
CONSIDERABLE...BUT AT LEAST WEAK CONDITIONAL INSTABILITY BASED NEAR
THE SURFACE IS EXPECTED AHEAD OF THE EASTWARD ADVANCING SURFACE COLD
FRONT. IN THE PRESENCE OF FAVORABLE DEEP LAYER SHEAR BENEATH STRONG
SOUTHWESTERLY MID/HIGH LEVEL FLOW...THIS WILL CONTRIBUTE TO THE RISK
FOR SEVERE STORMS...INCLUDING THE POTENTIAL FOR DAMAGING WINDS AND
TORNADOES...AS MODELS INDICATE THAT LARGE LOW-LEVEL HODOGRAPHS WILL
PERSIST THROUGH MUCH OF THE PERIOD BENEATH SOUTH SOUTHWESTERLY 850
MB FLOW ON THE ORDER OF 30-50 KT. MID/UPPER FORCING FOR UPWARD
VERTICAL MOTION IS UNCERTAIN...BUT FRONTAL LIFT COULD SUPPORT A
SQUALL LINE...PERHAPS PRECEDED BY ISOLATED SUPERCELLS...ACROSS PARTS
OF LOUISIANA AND MISSISSIPPI DURING THE DAYTIME HOURS...WHEN THE
SEVERE THREAT MAY BE THE GREATEST.
___________________________________________________
HWO for SELA:
.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY
NUMEROUS THUNDERSTORMS ARE EXPECTED TUESDAY AND TUESDAY NIGHT AS
A POTENT STORM SYSTEM AFFECTS THE AREA. A FEW STRONG TO SEVERE
THUNDERSTORMS WILL BE POSSIBLE TUESDAY AFTERNOON AND TUESDAY NIGHT
WITH THE MAIN THREATS BEING DAMAGING WIND GUSTS AND ISOLATED
TORNADOES.
SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR THE COASTAL
WATERS FROM TUESDAY THROUGH THURSDAY MORNING AS A STRONG COLD
FRONT APPROACHES AND MOVES THROUGH THE CENTRAL GULF COAST REGION
LATE TUESDAY NIGHT AND WEDNESDAY MORNING. WIND GUSTS MAY APPROACH
GALE FORCE AT TIMES IN THE WAKE OF THE COLD FRONT WEDNESDAY AND
WEDNESDAY NIGHT.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NEEDED.
Current SPC Outlook is a Slight Risk.
...CENTRAL GULF COAST/LOWER MISSISSIPPI VALLEY...
THE EVOLVING UPPER PATTERN IS EXPECTED TO SUPPORT THE CONTINUATION
OF A RETURN FLOW OF MOISTURE OFF THE WESTERN GULF OF MEXICO THROUGH
THE LOWER MISSISSIPPI VALLEY TUESDAY/TUESDAY NIGHT. LAPSE RATES
ACROSS THIS REGION LIKELY WILL BE WEAK...AND CLOUD COVER COULD BE
CONSIDERABLE...BUT AT LEAST WEAK CONDITIONAL INSTABILITY BASED NEAR
THE SURFACE IS EXPECTED AHEAD OF THE EASTWARD ADVANCING SURFACE COLD
FRONT. IN THE PRESENCE OF FAVORABLE DEEP LAYER SHEAR BENEATH STRONG
SOUTHWESTERLY MID/HIGH LEVEL FLOW...THIS WILL CONTRIBUTE TO THE RISK
FOR SEVERE STORMS...INCLUDING THE POTENTIAL FOR DAMAGING WINDS AND
TORNADOES...AS MODELS INDICATE THAT LARGE LOW-LEVEL HODOGRAPHS WILL
PERSIST THROUGH MUCH OF THE PERIOD BENEATH SOUTH SOUTHWESTERLY 850
MB FLOW ON THE ORDER OF 30-50 KT. MID/UPPER FORCING FOR UPWARD
VERTICAL MOTION IS UNCERTAIN...BUT FRONTAL LIFT COULD SUPPORT A
SQUALL LINE...PERHAPS PRECEDED BY ISOLATED SUPERCELLS...ACROSS PARTS
OF LOUISIANA AND MISSISSIPPI DURING THE DAYTIME HOURS...WHEN THE
SEVERE THREAT MAY BE THE GREATEST.
___________________________________________________
HWO for SELA:
.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY
NUMEROUS THUNDERSTORMS ARE EXPECTED TUESDAY AND TUESDAY NIGHT AS
A POTENT STORM SYSTEM AFFECTS THE AREA. A FEW STRONG TO SEVERE
THUNDERSTORMS WILL BE POSSIBLE TUESDAY AFTERNOON AND TUESDAY NIGHT
WITH THE MAIN THREATS BEING DAMAGING WIND GUSTS AND ISOLATED
TORNADOES.
SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR THE COASTAL
WATERS FROM TUESDAY THROUGH THURSDAY MORNING AS A STRONG COLD
FRONT APPROACHES AND MOVES THROUGH THE CENTRAL GULF COAST REGION
LATE TUESDAY NIGHT AND WEDNESDAY MORNING. WIND GUSTS MAY APPROACH
GALE FORCE AT TIMES IN THE WAKE OF THE COLD FRONT WEDNESDAY AND
WEDNESDAY NIGHT.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NEEDED.
