National Weather Service Weather Forecast Office

Area Forecast Discussion

959
FXUS64 KBMX 032126
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
326 PM CST SUN MAR 3 2013

.DISCUSSION...

THE SEEMING EVER-PRESENT CLOUDS THAT HAVE BEEN WITH US THANKS TO A
VERY SLOW MOVING UPPER LOW THAT HAS PERSISTED OVER THE EASTERN
CONUS HAVE FINALLY DISSIPATED THIS AFTERNOON AS THE UPPER PATTERN
IS FINALLY BECOMING PROGRESSIVE. SOME LOW TO MID LEVEL CLOUDS WILL
MOVE OVER THE NORTHERN PORTIONS OF THE AREA UNDER NORTHWEST FLOW
ALOFT AS A MID LEVEL SPEED MAX AND SHORTWAVE TROUGH PASS TO THE
NORTH OF THE AREA. EXPECT LOWS TO BE FAIRLY COLD AGAIN TONIGHT...
WITH UPPER 20S AND LOW 30S COMMON.

BY MONDAY AFTERNOON SOUTHERLY WINDS WILL BE ADVECTING MOISTURE
NORTHWARD INTO CENTRAL ALABAMA AHEAD OF AN UPPER LOW RIDING
SOUTHEASTWARD ALONG THE EASTERN EDGE OF A LONGWAVE RIDGE OVER THE
ROCKIES. HIGHS WILL FINALLY BE GETTING CLOSER TO MORE NORMAL
VALUES FOR THIS TIME OF YEAR... UPPER 50S TO MID 60S. RAIN CHANCES
RETURN FOR GENERALLY THE I-20 CORRIDOR AND POINTS NORTHWARD MONDAY
NIGHT. THE BEST CHANCE FOR RAIN AND A SLIGHT CHANCE OF ELEVATED
THUNDERSTORMS WILL BE DURING THE DAY ON TUESDAY. A COLD FRONT WILL
PASS THROUGH CENTRAL ALABAMA BY TUESDAY EVENING AS THE SURFACE LOW
AHEAD OF THE CLOSED UPPER LOW EJECTS FROM THE MID SOUTH INTO THE
OHIO VALLEY AND MID ATLANTIC.

MOST PRECIP SHOULD END BY LATE TUESDAY EVENING... BUT THERE IS
STILL SOME QUESTION AS TO WHETHER ANY FROZEN PRECIP COULD OCCUR IN
THE NORTHEASTERN COUNTIES OF CENTRAL ALABAMA BEFORE THE NECESSARY
MOISTURE IS REMOVED FROM THE LOWER ATMOSPHERE. IT WILL PROBABLY BE
COLD ENOUGH... BUT FOR NOW JUST LEFT THE SLIGHT CHANCE OF A
RAIN/SNOW MIX IN AFTER MIDNIGHT TUESDAY INTO WEDNESDAY DUE TO THE
APPARENT LACK OF MOISTURE. EVEN THOUGH THE GFS IS SPITTING OUT
SOME LIGHT QPF ON WEDNESDAY ACROSS THE TENNESSEE VALLEY AND FAR
NORTHEASTERN CENTRAL ALABAMA ON THE BACKSIDE OF THE UPPER LOW...
THINK THAT ANY PRECIP THAT FALLS WILL BE TOO LIGHT TO MEASURE...
AND SO KEPT POPS 10 PERCENT OR LESS FOR WEDNESDAY.

THE REMAINDER OF THE FORECAST WILL FEATURE GRADUALLY WARMING
TEMPERATURES EACH AFTERNOON THURSDAY THOUGH NEXT SUNDAY. RAIN
CHANCES LOOK MINIMAL. AT THE VERY END OF THIS FORECAST PERIOD BOTH
GFS AND ECMWF ARE ADVERTISING SOME FORM OF AN UPPER LOW MOVING
OVER THE SOUTHERN PLAINS... AND MOISTURE RETURN OCCURRING ACROSS
THE DEEP SOUTH AHEAD OF THE UPPER LOW. THIS WOULD SUGGEST THAT
RAIN CHANCES COULD RETURN BY EARLY NEXT WEEK... WHICH IS JUST
BEYOND THE CURRENT FORECAST PERIOD.

77/GLEASON

&&

.AVIATION...
18Z TAF DISCUSSION.

CLEARING SKIES WILL PREVAIL FOR THIS TAF CYCLE AS YESTERDAYS SYSTEM
MOVES OFF TO THE EAST. WINDS AT THE SURFACE WILL CONTINUE TO BE
BREEZY THIS AFTERNOON...BEFORE CALMING DOWN AFTER SUNSET. HIGH
PRESSURE WILL SHIFT EASTWARD JUST TO OUR SOUTH...WITH SURFACE WINDS
SHIFTING OUT OF THE SOUTH BY MONDAY MORNING. THE SOUTHEASTERLY
SURFACE WINDS WILL ALLOW MORE MOISTURE TO FILTER IN AND HIGH CLOUDS
WILL BEGIN TO MOVE IN AHEAD OF THE NEXT SYSTEM THAT WILL AFFECT THE
AREA ON TUESDAY.

73

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     28  58  47  60  32 /   0  10  40  80  40
ANNISTON    28  59  48  61  33 /   0  10  30  80  40
BIRMINGHAM  30  60  51  61  33 /   0  10  30  80  30
TUSCALOOSA  30  65  53  63  35 /   0  10  30  70  20
CALERA      31  62  51  62  34 /   0   0  30  80  30
AUBURN      30  60  48  64  34 /   0   0  20  60  40
MONTGOMERY  30  64  50  67  36 /   0   0  20  60  30
TROY        28  63  49  68  37 /   0   0  20  60  40

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

77/73