FXUS64 KBMX 261143
AFDBMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
543 AM CST SAT DEC 26 2009
.UPDATE...FOR AVIATION DISCUSSION.
&&
.SHORT TERM...TODAY THROUGH TUESDAY.
A COOL START TO YOUR SATURDAY MORNING WITH LOWS IN THE 20S. THE
DOMINANT WEATHER FEATURE CONTINUES TO BE THE SPRAWLING UPPER LOW
OVER THE MIDWEST. ONE MORE SPOKE OF VORTICITY WILL WRAP AROUND THE
BASE OF THAT LOW SUNDAY AND WILL TRY TO INITIATE SOME
PRECIPITATION TO OUR SOUTH. TRENDS ARE PUSHING THE PRECIP FARTHER
SOUTH WITH EACH RUN SO THINK WE WILL REMAIN DRY THROUGH THE
WEEKEND.
THE UPPER LOW WILL BEGIN TO LIFT OFF TO THE NORTHEAST SUNDAY
NIGHT WITH RE-ENFORCING HIGH PRESSURE BUILDING INTO THE AREA
MONDAY AND TUESDAY.
TEMPERATURES THROUGH THE SHORT TERM LOOK BELOW AVERAGE AND KNOCKED
OFF A COUPLE DEGREES FROM GUIDANCE FOR HIGHS AS 1000-850MB
THICKNESS VALUES WERE A BIT COOLER. LOWS ARE EXPECTED TO RANGE
FROM THE LOWER 20S TO LOWER 30S.
.LONG TERM...TUESDAY NIGHT THROUGH FRIDAY.
AN ACTIVE SOUTHERN STREAM PATTERN WILL REDEVELOP BEGINNING TUESDAY
NIGHT AS A TROUGH TRANSITIONING OUT OF THE SOUTHWEST CONUS
GENERATES A SURFACE LOW IN THE NORTHWESTERN GULF. MODELS ARE
SHOWING SOME LIGHT PRECIPITATION DEVELOPING ACROSS CENTRAL ALABAMA
MAINLY AFTER MIDNIGHT. SOUNDING PROFILES ARE COLD ENOUGH FOR SNOW
ALOFT BUT SEE IT AS TOO WARM IN THE LOWER LEVELS. BECAUSE OF THE
DRY AIR IN PLACE...I WOULD EXPECT SOME ICE PELLETS TO BE POSSIBLE
ESPECIALLY ALONG THE LEADING EDGE OF THE PRECIP SHIELD ACROSS THE
NORTHERN COUNTIES. SHOULD ONLY BE A LIGHT RAIN IN THE SOUTH. WILL
ONLY GO SLIGHT CHANCE FOR NOW BUT THE 00Z RUNS WERE TRENDING
WETTER DURING THE EARLY MORNING HOURS.
MODELS ARE IN GOOD AGREEMENT WITH THE DEVELOPMENT OF THE SURFACE
LOW IN THE NORTHWESTERN GULF AND CONFIDENCE HAS INCREASED
SIGNIFICANTLY WITH RESPECT TO POPS DURING THE DAY WEDNESDAY. SOME
TIMING DIFFERENCES WITH THE EXIT OF THIS SYSTEM WITH THE GFS BEING
MUCH MORE PROGRESSIVE THAN THE EURO. THIS SYSTEM HAS A SIMILAR
FEEL TO LAST WEEKS THAT BROUGHT HEAVY RAINS TO THE DEEP SOUTH AND
DELIVERED HEAVY SNOWS UP THE EAST COAST. WENT WITH THE SLOWER AND
MORE PERSISTENT EURO FOR TIMING WHICH CAUSED AN INCREASE IN POPS
BOTH WEDNESDAY NIGHT AND THURSDAY.
VERY COLD AIR SEEMS TO BE FOLLOWING THE MID WEEK SYSTEM WITH A
SLIGHT CHANCE OF SOME LIGHT SNOW DEVELOPING ON THE BACK END OF THE
EXITING TROUGH THURSDAY NIGHT AND LEADING EDGE OF THE DIGGING
POLAR VORTEX THAT KEEPS WANTING TO DROP DOWN INTO THE EASTERN U.S.
A LOWER CONFIDENCE FORECAST WITH HOW THIS SYSTEM AND ANY
PRECIPITATION WILL FINALLY EXIT THE AREA. TEMPERATURES SHOULD BE
ABOUT 10 DEGREES BELOW CLIMATE AS WE APPROACH THE WEEKEND.
&&
.AVIATION...12Z TAF DISCUSSION.
SCATTERED TO BROKEN HIGH CLOUDINESS WILL PERSIST OVER THE TAF SITES
AS MOISTURE ASSOCIATED WITH THE SUBTROPICAL JET BOWS NORTHWARD OVER
ALABAMA. THE JET MOVES EAST OF THE TAF SITES AFTER 27/00Z. SURFACE
RIDGE OF HIGH PRESSURE WILL EXTEND EASTWARD OVER SOUTH
ALABAMA...MAINTAINING A RELATIVELY LIGHT SOUTHWEST WIND REGIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
GADSDEN 48 25 49 25 45 / 0 10 10 10 0
ANNISTON 51 28 49 27 47 / 0 10 10 10 0
BIRMINGHAM 50 33 50 27 46 / 0 10 10 10 0
TUSCALOOSA 52 31 51 27 49 / 0 10 10 10 0
CALERA 52 33 50 28 47 / 0 10 10 10 10
AUBURN 51 33 51 29 48 / 0 10 10 10 0
MONTGOMERY 55 31 52 29 50 / 0 10 10 10 0
TROY 56 30 52 29 50 / 0 10 20 10 0
&&
.BMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
88/03
