FXUS64 KHUN 262338 AAA
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
540 PM CST THU NOV 26 2009

.UPDATE...FOR 00Z AVIATION DISCUSSION.
&&

.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
&&

.PREV DISCUSSION.../ISSUED AT 140 PM CST THU NOV 26 2009/
THANKSGIVING 2009 HAS BEEN DRY...BUT RATHER COOL AND BREEZY AS A 
REINFORCING COLD FRONT DEPARTS TO THE SE. WV IMAGERY INDICATES A 
SHARP DEEP TROUGH PIVOTING THROUGH THE REGION...AND AN EXPANSIVE 
AREA OF STRATUS EXTENDS NWD FROM THE TN-AL STATE LINE. THE TIGHT 
PRESSURE GRADIENT IS ALSO ALLOWING FOR RATHER GUSTY NW WINDS AND 
STRONG COLD AIR ADVECTION /CAA/...WHICH HAS LIMITED TEMPERATURES 
FROM GETTING MUCH ABOVE 50F THIS AFTN.

FCST THRU THE WEEKEND MAINLY DEALS WITH TEMPERATURES...ESPECIALLY 
TONIGHT AND FRIDAY NIGHT WHEN THERE IS THE CHANCE OF A LIGHT FREEZE. 
A SFC HIGH CURRENTLY CENTERED OVER THE SRN PLAINS WILL BUILD EWD 
THIS EVENING...EVENTUALLY REACHING THE LA GULF COAST BY DAYBREAK. 
NOT SURE THAT SKIES WILL CLEAR ENOUGH...OR WINDS WILL DECOUPLE 
ENOUGH...FOR IDEAL RADIATIONAL COOLING CONDITIONS TONIGHT. THUS WILL 
GO FAIRLY CLOSE TO THE COOLER NAM MOS...WHICH WOULD LIKELY MEAN A 
LIGHT AND BRIEF FREEZE FOR THOSE AREAS THAT HAVE SOMEHOW NOT YET 
FROZEN THIS FALL. 

ONLY SLIGHTLY WARMER CONDITIONS ARE EXPECTED TMRW AS THE HIGH 
CONTINUES EWD ALONG THE GULF COAST. TMRW NIGHT MAY PRESENT THE 
BETTER OPPORTUNITY FOR A WIDESPREAD FREEZE AS THEN-SOUTHERLY WINDS 
MAY BETTER DECOUPLE. SOUTHERLY FLOW WILL BECOME MORE ESTABLISHED 
SATURDAY...LEADING TO A NICE WARM-UP INTO THE LOWER 60S SAT AFTN... 
AND LOW/MID 40S SAT NIGHT. OTHER THAN TRENDING BELOW MOS FRIDAY 
NIGHT...A MOS BLEND LOOKS REASONABLE OTHERWISE.

MUCH OF THE EXTENDED PERIOD WILL BE TAKEN UP BY AN UNSETTLED AND 
COMPLICATED WX PATTERN...LEADING TO RELATIVELY COOL AND OCCASIONALLY 
WET WEATHER. MODEL/ENSEMBLE AGREEMENT ON THE EARLY PART OF THE PD IS 
GOOD...WITH A BAND OF RAIN ACCOMPANYING A SFC FRONT/SHARP UPPER 
TROUGH LATE SUNDAY. IN LIGHT OF THE PRECEDING SRLY FLOW AND HIGH 
PWATS...AS WELL AS GOOD FORCING...HAVE A HARD TIME UNDERSTANDING THE 
RELATIVELY LOW POPS OFFERED BY THE 00Z GFSX MOS HERE. WILL AVOID 
CATEGORICAL POPS DUE TO TYPICAL UNCERTAINTY AT THAT TIME RANGE BUT 
FEEL FAIRLY CONFIDENT IN A WET MONDAY. THE DRIVING TROUGH WILL BE A 
PROGRESSIVE ONE SO CONDITIONS ARE LIKELY TO DRY OUT QUICKLY /BY 
TUESDAY MORNING/ AS THE FRONT IS DRIVEN SWD TO THE GULF COAST. 
PREFRONTAL TEMPS MAY REACH THE 60S AGAIN SUNDAY...BUT COOLER- 
THAN-NORMAL CONDITIONS WILL QUICKLY TAKE HOLD BEHIND THE FRONT.

AS USUAL...MAIN UNCERTAINTY DEALS WITH A CUTOFF LOW THAT WILL BE 
ORPHANED BEHIND THE FASTER-MOVING NRN STREAM TROUGH. THE LOW WILL BE 
KICKED EWD INTO THE NRN GULF DUE TO ANOTHER DEEPENING TROUGH OVER 
THE GREAT PLAINS. HOWEVER...SOLUTIONS DIVERGE SHARPLY ON THE 
LOCATION AND DEPTH OF THE TROUGH...WHICH IN TURN AFFECTS THE TRACK 
AND SPEED OF THE LOW. ECMWF SOLN LOOKS A LITTLE TOO WET...THE GFS 
TOO DRY...BUT CHANCE POPS APPEAR WARRANTED EITHER WAY GIVEN THE 
PROXIMITY TO THE LOW. ALL OF THIS WILL BE OCCURRING WITH NORTHERLY 
FLOW SO IT WILL BE A CHILLY RAIN...BUT NOT COLD ENOUGH FOR ANY PTYPE 
CONCERNS.

ON BEHALF OF ALL OF US AT NWS HUNTSVILLE...HAPPY THANKSGIVING!
&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&
$$

DISCUSSION...BCC
AVIATION...JLL