FXUS64 KHUN 060526 AAC
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1120 PM CST SAT DEC 5 2009

.UPDATE...
06Z AVIATION DISCUSSION.
&&

.AVIATION...
HIGH CLOUDS WILL CONTINUE TO INCREASE...ESPECIALLY AFTER DAYBREAK 
TOMORROW. LOW/MID CLOUDS COULD ENCROACH ON KMSL BY THE END OF THE 
TAF PERIOD...BUT EVEN SO...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 
24 HOURS.
&&

.DISCUSSION...
WITH BROAD HIGH PRESSURE IN CONTROL ACROSS THE CENTRAL TENNESSEE 
VALLEY...TEMPERATURES ARE QUICKLY DROPPING INTO THE 20S...LEADING TO 
WHAT WILL EASILY BE THE COLDEST NIGHT OF THE SEASON SO FAR. AS A 
RESULT OF THE QUICK DROPOFF...AND DEWPOINTS IN THE LOWER 20S...TEMPS 
ARE ALREADY APPROACHING THE FORECAST LOWS IN THE COLD POCKETS. 
THUS...WILL LOWER MIN TEMPS IN THOSE SPOTS. CONVERSELY...HIGH CLOUDS 
ARE STREAMING INTO THE AREA...AND WHILE THEY ARE GENERALLY 
THIN...THERE WILL PROBABLY BE ENOUGH OF THEM SUCH THAT "CLEAR" IS 
NOT REALLY ACCURATE. WILL RAISE SKY COVER TO MOSTLY CLEAR AND REALLY 
IT COULD BE MORE LIKE PARTLY CLOUDY BY LATE TONIGHT.
&&

.PREV DISCUSSION...
COLD DOME OF HIGH PRESSURE IS CURRENTLY MOVING EWD INTO THE LOWER MS 
AND TN VALLEYS THIS AFTERNOON...AND THIS TREND SHOULD CONTINUE 
THROUGH THE EVENING AND OVERNIGHT HRS. THIS SHOULD TRANSLATE INTO A 
RATHER COLD NIGHT WITH OVERNIGHT LOWS FALLING INTO THE LOW/MID 20S 
RANGE UNDER CLR SKIES. THE SFC HIGH IS THEN XPCTED TO QUICKLY PUSH 
OFF TOWARD THE NE ON SUN AS A WEAK/DECAYING COLD FRONT MOVES THROUGH 
THE REGION MON. RAIN IS ALSO XPCTED TO DEVELOP ALONG AND AHEAD OF 
THIS FRONT LATE SUN NIGHT AND MON BEFORE A BRIEF CLRING TREND THEN 
XPCTED MON NIGHT. OVERALL TEMPS/CONDITIONS LOOK TO REMAIN QUITE COLD 
ACROSS THE AREA THROUGH MON NIGHT WITH A MOD POLAR AIR MASS 
REMAINING FAIRLY ENTRENCHED.

THE FORECAST THEN SHIFTS TOWARD THE MIDDLE OF NEXT WEEK WHERE A MORE 
POTENT LOW PRESSURE SYSTEM IS XPCTED TO IMPACT THE SE REGION. THE 
GLOBAL MODELS STILL POINT TOWARD A DEEPENING SFC LOW OUT OF THE SRN 
PLAINS RACING TOWARD THE OH VALLEY TUE NIGHT/WED...WITH WIDESPREAD 
RAINFALL DEVELOPING ACROSS MUCH OF THE SE. THE MODELS SUGGEST QUITE 
A BIT OF MID/UPPER FORCING ACCOMPANYING THE SFC LOW WHICH COULD 
RESULT IN SOME BOUTS OF HEAVY RAINFALL. LOW LEVEL INSTABILITY THOUGH 
CONTINUES TO APPEAR RATHER WEAK SUGGESTING LITTLE IF ANY SUPPORT FOR 
TSTMS AT THIS TIME. PRECIP WILL THEN BEGIN TO TAPER OFF ON WED AS A 
TRAILING COLD FRONT MOVES THROUGH THE AREA WITH COOLER AND DRIER AIR 
IN TOW.

ANOTHER STRONG...COLD DOME OF SFC HIGH PRESSURE OUT OF THE NRN/CNTRL 
PLAINS IS THEN XPCTED TO MOVE INTO THE REGION ON THU BEFORE MOVING E 
FRI. YET ANOTHER LOW PRESSURE/WEAK CLIPPER-LIKE SYSTEM OUT OF SE TX 
IS THEN XPCTED TO MOVE ACROSS THE AREA LATE FRI AND SAT WITH 
ADDITIONAL RAIN CHANCES POSSIBLE.
&&

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

$$

DISCUSSION/AVIATION...JE/23
PREV DISCUSSION...09