FXUS64 KBMX 150540
AFDBMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1140 PM CST MON DEC 14 2009
.UPDATE...FOR AVIATION.
&&
.DISCUSSION...
LATEST SURFACE ANALYSIS SUGGESTS THAT THE IMPENDING WARM FRONT IS
JUST TO OUR SOUTH AND MUCH OF THE ACTION THROUGH THE EVENING HAS
REMAINED ALONG THAT BOUNDARY...AND SOUTH OF THE AREA. STRONG
ROTATING THUNDERSTORMS HAVE DEVELOPED ALONG THE BOUNDARY...WHICH
SENT A COLD POOL AND REDEVELOPMENT EVEN FURTHER SOUTH...LEAVING OUR
SOUTHEASTERN CWA IN AN OVER RUNNING MODERATE TO LIGHT RAIN MASS.
THE POTENTIAL FOR ADDITIONAL HEAVY RAINFALL HAS WAINED A BIT WITH
THIS NEW WRINKLE AND THE LATEST NUMERICAL GUIDANCE SUGGESTS THAT
FURTHER DEVELOPMENT MAY BE HARD TO COME BY AS THE SURFACE COLD POOL
HAS ESSENTIALLY CUTOFF THE SURFACE MOISTURE FLOW FURTHER NORTH. AS
SAID...IT WOULD SUGGEST THAT THE HEAVIEST RAINFALL WOULD REMAIN
SOUTH THROUGH THE REMAINDER OF THE OVERNIGHT...HOWEVER...WITH THE
POTENTIAL FOR A RESURGENCE OF THE MAIN WARM FRONT FURTHER NORTH INTO
THE EARLY MORNING HOURS AND TOMORROW AFTERNOON...DECIDED TO KEEP THE
FLASH FLOOD WATCH IN PLACE THROUGH TOMORROW.
FURTHER NORTH...THE COLD FRONT THAT WILL FINALLY INTRODUCE COOLER
AND DRIER CONDITIONS IS JUST OFF THE NORTHWEST AND MAY TAKE ITS TIME
IN DIGGING SOUTH. BY TOMORROW AFTERNOON...AT LEAST THE NORTHERN
HALF OF THE AREA IS EXPECTED TO SEE THE WINDS SHIFT TO THE
NORTHWEST...BRINGING THE END TO THE THREAT OF ADDITIONAL SHOWERS.
THERE MAY BE A SMALL OPPORTUNITY FOR ADDITIONAL DEVELOPMENT ALONG
THE COLD FRONT THROUGH TOMORROW AFTERNOON...HOWEVER...IT IS EXPECTED
TO ONLY REMAIN LIGHT TO MODERATE...IF AT ALL. BY TOMORROW
NIGHT...THE COLD FRONT WILL MOVE THROUGH THE SOUTH ENDING RAIN
CHANCES FOR ALL COUNTIES.
17/KLAWS
&&
.AVIATION...06Z TAF DISCUSSION.
SHOWERS AND STORMS WILL CONTINUE TO IMPACT THE SOUTHERN SITES...
WHILE LOW CLOUDS AND RESTRICTED VISIBILITIES WILL IMPACT THE
NORTHERN SITES. WILL CONTINUE IFR AND LIFR THROUGH 19 TO 21Z THIS
AFTERNOON.
EXPECTING FOR THE HEAVIER RAIN SHOWERS TO ONLY AFFECT THE SOUTHERN
TAF SITES. WILL ADJUST THE FORECAST IF NEEDED IF IT APPEARS
OTHERWISE SINCE COMPUTER MODELS ARE CONFIDENT THAT THE HEAVY RAIN
WILL REMAIN SOUTHWARD. MAY SEE JUST A FEW MORE HOURS...6Z TO 8Z OF
VFR TO MVFR CONDITIONS...ALTHOUGH ONLY TEMPORARY. SO FORECAST IS ON
THE MORE PESSIMISTIC SIDE FOR MGM AND TOI.
THE COLD FRONT IS BEGINNING TO ENTER NW ALABAMA AS OF THIS UPDATE.
EXPECT A WIND SHIFT TO THE NORTH AFTER THE FRONT MOVES THROUGH...BUT
NOT EXPECTING CEILINGS TO LIFT MUCH. FINALLY EXPECTING CLEARING...AT
LEAST LOWER CEILINGS FOR THE NORTH AFTER 21Z. LOWER CEILINGS IMPROVE
TO MVFR FOR THE SOUTH AFTER 21Z. IMPROVEMENT HERE IS EXPECTED AFTER
00Z TOMORROW. MAY EVEN SEE SCATTERED CLOUDS AFTER 00Z...BUT DID NOT
INCLUDE AS FORECAST ALREADY WAS FOR VFR CONDITIONS. OTHERWISE WINDS
WILL BE GUSTY THIS AFTERNOON BEHIND THE FRONT AS WELL WITH 10 TO
12KT SUSTAINED WITH HIGHER GUSTS. MORE DETAIL TO COME WITH THIS IN
THE UPCOMING FORECAST.
16
&&
.BMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY FOR ALL OF CENTRAL AL THROUGH 10 AM CST TUESDAY.
FLASH FLOOD WATCH FOR TALLAPOOSA...CHAMBERS...DALLAS...AUTAUGA...
LOWNDES...ELMORE...MONTGOMERY...MACON...BULLOCK...LEE...RUSSELL...
PIKE...AND BARBOUR COUNTIES UNTIL 6 PM CST TUESDAY.
&&
$$
