FXUS64 KHUN 151650 AAB
AFDHUN

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1050 AM CST TUE DEC 15 2009

.UPDATE...
REMOVED RAIN CHANCES FOR OUR SE COUNTIES THE REST OF TODAY...AND 
MADE ADJUSTMENTS TO CLOUD COVER.

&&

.DISCUSSION...
A COLD FRONT MOVED ACROSS THE TENNESSEE VALLEY OVERNIGHT. AS OF 10 
AM...IT EXTENDED ROUGHLY FROM WEST OF CHARLOTTE NC...TO ATLANTA TO 
NORTH OF MONTGOMERY. DESPITE THE FRONT'S PASSAGE...EXTENSIVE CLOUDS 
REMAIN BEHIND IT. MOST OF THESE CLOUDS ORIGINATED IN THE SUBTROPICS 
FROM SOUTH OF MEXICO...HOWEVER A FEW SPOTS OF MVFR ALTITUDE CLOUDS 
(1000-3000 FT AGL) EXISTED ACROSS THE VALLEY. 

A VISIBLE SATELLITE PERSPECTIVE INDICATED A FEW POSSIBLE BREAKS IN 
THE LOWER CLOUD DECK...WHICH MEANS A BRIEF GLIMPSE OF SUNSHINE IS A 
POSSIBILITY. OTHERWISE THE MORE PREDOMINATE MID/HIGHER ALTITUDE 
CLOUD COVERAGE WILL CONTINUE...WITH IT BEING MORE CLOUDY THAN MOSTLY 
CLOUDY. COOLER AIR SEEPING INTO THE REGION WILL MAKE FOR A WIDE 
TEMPERATURE SPREAD CONCERNING HIGHS FOR THE REMAINDER OF THE DAY. 
MOST LOCATIONS HAD HIGH TEMPS AROUND MIDNIGHT OR DURING THE PREDAWN 
BEFORE THE FRONT. TEMPS TODAY SHOULD STAY STEADY OR SLOWLY FALL THIS 
AFTERNOON AS COLD AIR ADVECTION CONTINUES INTO THE EVENING.

HAVE ALREADY UPDATED AND SHIPPED THE TEXT FORECASTS FOR TODAY. 

&&

.AVIATION...   /ISSUED 523 AM CST TUE DEC 15 2009/
MVFR CIGS WILL CONTINUE INTO AT LEAST EARLY AFTERNOON. WILL INDICATE 
HIGH CLOUDS ONLY AFTER THAT POINT WITH VFR CONDITIONS. COULD BE AN 
ISOLATED SHRA SOUTH/SOUTHEAST OF KHSV IN THE NEXT FEW HOURS...BUT 
ACTIVITY CURRENTLY ON RADAR DOES NOT APPEAR TO COME CLOSE ENOUGH TO 
INDICATE VCSH AT THIS POINT.
&&

.PREV DISCUSSION...  /ISSUED 250 AM CST TUE DEC 15 2009/

SHORT TERM...THROUGH THURSDAY...
SFC COLD FRONT IS RAPIDLY PROGRESSING ACROSS THE HUN CWFA THIS 
MORNING...AND AS OF 08Z IS ROUGHLY ALONG A COLUMBUS MS-ALBERTVILLE- 
CROSSVILLE TN LINE. NO PCPN OF ANY REAL CONSEQUENCE MATERIALIZED 
THIS FAR N...WITH THE BULK OF THE MOISTURE/GULF INFLOW HAVING BEEN 
INTERCEPTED BY CONVECTION CLOSER TO THE GULF COAST. ONE OR TWO PTS 
SE OF HSV HAVE ACTUALLY MEASURED MORE THAN A TRACE WITHIN -RA...BUT 
LITTLE ELSE HAS BEEN OBSERVED. PREFRONTAL TEMPS/DEWPTS REMAIN IN THE 
LOWER 60S. POSTFRONTAL TEMPS TAKE SOME TIME TO FALL OFF...BUT THEY 
DO SO QUICKLY AS YOU APPROACH THE CENTER OF THE 1036MB HIGH...WHICH 
IS CURRENTLY OVER NEBRASKA.

THERE IS NO QUESTION THAT WE HAVE HIT /OR ARE HITTING/ OUR HIGHS FOR 
TODAY...AS LOW CLOUDS AND STRONG COLD AIR ADVECTION /CAA/ RESULT IN 
SLOWLY FALLING TEMPS THROUGH THE DAY. OTHER QUESTION FOR TODAY IS 
WHETHER ANYONE WILL SEE ANY ADDITIONAL -RA/-DZ AS THE UPPER TROUGH 
AXIS PUSHES THROUGH LATE THIS AFTN. FEEL THAT THE MOISTURE IS FAR 
TOO SHALLOW AND PVA TOO WEAK TO GET MUCH IF ANY ADDL PRECIP. IN 
FACT...IF CURRENT SAT TRENDS ARE ANY INDICATION...WE MAY SEE A FEW 
BREAKS IN THE CLOUDS EARLY THIS MORNING OR AGAIN LATE IN THE DAY. 
SKIES SHOULD CLEAR FOR TONIGHT...THOUGH SOME LT CIRRUS MAY LINGER. A 
STILL-TIGHT PRSR GRADIENT WILL KEEP WINDS IN THE 5-10KT RANGE SO 
LOWS WILL BE MOSTLY ADVECTION-DRIVEN. BASED ON UPSTREAM OBS...FEEL 
THE COOLER NAM MOS IS SLIGHTLY BETTER.

THE SUN MAY FINALLY MAKE A RETURN APPEARANCE TO THE REGION WEDNESDAY 
/ASIDE FROM SOME THIN CIRRUS INDICATED BY MDL SOUNDINGS/. WEAK CAA 
WILL LIKELY CONTINUE SO IT WILL NOT EXACTLY BE WARM...BUT HIGHS MAY 
GET CLOSE TO SEASONAL AVGS. THE BOTTOM MAY FALL OUT WED NIGHT AS 
GOOD RADNL COOLING AND A DRY ATMOSPHERE TAKE HOLD...AND HAVE 
UNDERCUT THE GFS MOS. CONDITIONS SHOULD REBOUND NICELY FOR THURSDAY 
AS THE SFC HIGH MOVES INTO THE MID-ATLANTIC.

LONG TERM...FRIDAY THROUGH MONDAY...
SOME CUTOFF ENERGY OVER TX WILL EVENTUALLY SKIRT THE AREA TO THE 
SOUTH LATE THURSDAY INTO FRIDAY. THE VAST MAJORITY OF OPRNL MODELS/ 
ENSEMBLES KEEP THE RAIN CONFINED TO THE FRONT WELL TO THE SOUTH. 
THIS DRIER SOLN LOOKS MORE REASONABLE THAN THE MUCH-WETTER ECMWF... 
THOUGH IT MAY INDUCE SOME RENEWED NORTHERLY FLOW AND COOLER WX.

WINTER WILL MAKE A REAPPEARANCE HEADING FOR THE WEEKEND AS A HIGHLY 
AMPLIFIED PATTERN EVOLVES OVER THE GREAT LAKES/MIDWEST...AND A 
POTENT SHORTWAVE SWINGS THROUGH THE AREA. AT THE VERY LEAST THIS 
WILL DROP TEMPERATURES TO ROUGHLY 10 DEGREES BELOW NORMAL. OPRNL 
GFS/ECMWF CONTINUE TO PRINT OUT SOME LT QPF IN THE VICINITY OF THIS 
WAVE /THOUGH THE GFS IS BY FAR THE WETTEST OF THE GEFS MEMBERS/. THE 
SYSTEM WILL BE RELATIVELY MOISTURE-STARVED...BUT LT PCPN IS 
REASONABLE GIVEN THE TIME OF YEAR AND INTENSITY OF THE TROUGH. SFC 
TEMPS AND SOUNDINGS SUGGEST AT LEAST SOME OF THAT FALLING AS SNOW AS 
THE BLYR COOLS...BUT WILL LIKELY BE TOO LIGHT TO AMT TO VERY MUCH. 
MODEL SPREAD PEAKS BY DAY 7 WITH THE ECMWF SENDING A TRAIN OF S/W 
ENERGY THRU THE AREA IN NW FLOW...VERSUS THE MORE PROGRESSIVE/DRIER 
GFS. HAVE TRENDED TOWARD THE GFS...BUT EITHER SOLN WILL MEAN A 
CONTINUATION OF THE COOL PATTERN. THUS STAYED CLOSE TO OR JUST BELOW 
THE GFSX MOS FOR TEMPS.

&&

.CLIMATE...
FAST FACT...YESTERDAYS HIGH OF 70 WAS THE WARMEST RECORDED AT 
HUNTSVILLE IN NEARLY A MONTH...SINCE NOVEMBER 16TH. THE LOW OF 54 
WAS THE WARMEST RECORDED SINCE NOVEMBER 10TH. ON AVERAGE...WE REACH 
70 IN DECEMBER ABOUT TWICE EVERY OTHER YEAR. YESTERDAY MARKS THE 
FOURTH YEAR IN A ROW WITH 70+ TEMPS IN DECEMBER...AND IS THE NINTH 
SUCH OCCURRENCE IN THAT FOUR YEAR PERIOD.

&&

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

$$

UPDATE...RB
SHORT TERM/LONG TERM...BCC
AVIATION/CLIMATE...JE/23