FXUS64 KBMX 021558
AFDBMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
958 AM CST WED DEC 2 2009
.UPDATE...MESOSCALE UPDATE.
&&
.DISCUSSION...
WE ARE NOT QUITE READY TO SAY THINGS ARE ALL OVER FOR CENTRAL
ALABAMA...AT LEAST AS FAR AS THE SEVERE WEATHER THREAT.
LATEST SURFACE MESO-ANALYSIS SHOWS A SURFACE LOW SOMEWHERE BETWEEN
TCL AND BHM...WITH A WARM/STATIONARY FRONT EXTENDING EASTWARD AND
THEN SOUTHEASTWARD FROM IT INTO GEORGIA...AND A COLD FRONT EXTENDING
SOUTH-SOUTHWESTWARD INTO SOUTH MS. THE WARM SECTOR HAS SURGED UP TO
AROUND BHM AND ANB...AND DEWPOINTS IN THIS AREA ARE RUNNING SEVERAL
DEGREES AHEAD OF WHAT THE MODELS HAD PREDICTED. THERE'S A BROAD AREA
OF LOW PRESSURE IN NORTH MS...WHICH IS LIKELY LINKED TO THE CENTRAL
ALABAMA LOW BY AN OCCLUDED FRONT. I SUSPECT THAT AS THE UPPER LEVEL
SHORTWAVE TROUGH SWINGS EASTWARD THE REST OF THIS MORNING AND
AFTERNOON...THE CENTRAL ALABAMA LOW WILL BECOME THE MAIN LOW.
THERE ARE SOME THIN SPOTS IN THE OVERCAST SHOWING UP ON VISIBLE
SATELLITE IN THE WESTERN COUNTIES...AS A DRY SLOT TRIES TO PUNCH IN
AHEAD OF THE SHORTWAVE. THE THIN SPOTS SO FAR HAVE BEEN ON THE COLD
SIDE OF THE COLD FRONT. HOWEVER...IF SOME OF THOSE HOLES/THIN SPOTS
IN THE OVERCAST CAN GET FARTHER EAST INTO THE WARM SECTOR...THEN
THAT COULD HELP DESTABILIZE THINGS JUST A LITTLE BIT. AND WITH THE
PRESSURE GRADIENT CONTINUING TO THE EAST OF THE COLD FRONT...LOW
LEVEL SHEARS SHOULD STAY UP A BIT AS WELL.
LATEST THINKING IS THAT THERE WILL BE A NARROW WINDOW OF OPPORTUNITY
(IN BOTH TIME AND SPACE) OF THUNDERSTORM DEVELOPMENT. AREA-WISE...
THIS WOULD BE FROM THE CITIES OF SYLACAUGA AND PRATTVILLE...SOUTH
AND EASTWARD. TIMING-WISE...THIS WOULD BE FROM AROUND NOON UNTIL 4
OR 5 PM. KEEP IN MIND THAT THE CHANCES REMAIN SMALL (BUT
NON-ZERO)...AND CONFIDENCE IS FAIRLY LOW. JUST SOMETHING TO WATCH
AND ANTICIPATE FOR THE REST OF TODAY.
/61/
&&
.AVIATION...12Z TAF DISCUSSION.
STRONG WIND...LOW CEILINGS...RAIN AND LLWS WILL BE A CONCERN TODAY
AS A GULF LOW TRACKS NORTHWARD ALONG THE MISSISSIPPI/ALABAMA STATE
LINE. THE HEAVIEST RAIN WILL LIKELY FALL BEFORE 15Z REDUCING VISBYS
TO 3 MILES AT MGM AND TOI. CURRENT RADAR TRENDS INDICATE THAT
RAINFALL WILL COME TO AN END EARLIER THAN PREVIOUSLY EXPECTED...RAIN
FREE PREVAILING CONDITIONS ARE NOW EXPECTED AT ALL SITES BY 18Z.
EASTERLY WIND AROUND 10 KNOTS WILL INCREASE TO BETWEEN 10 AND 20
KNOTS BY 14Z WITH GUSTS TO 25 KNOTS. BEFORE SURFACE WIND INCREASES
LLWS COULD BE A PROBLEM.
CEILINGS WILL VARY AS RAIN BANDS IMPACT INDIVIDUAL LOCATIONS BUT FOR
THE MOST PART WILL NOT GO ABOVE 1500 FEET ALL DAY AND SHOULD DROP
BELOW 1000 FEET AGAIN AFTER 01Z THIS EVENING.
&&
.BMX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY IS IN EFFECT TONIGHT UNTIL 6 PM TODAY FOR ALL OF
CENTRAL ALABAMA.
&&
$$
