Area Forecast Discussion
Issued by NWS Birmingham, AL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KBMX 020501
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1201 AM CDT THU OCT 2 2014

.UPDATE...
FOR 06Z AVIATION.

&&

.DISCUSSION...

AN UPPER LEVEL TROUGH IS CURRENTLY MOVING ACROSS THE ROCKY
MOUNTAINS INTO THE CENTRAL PLAINS. A SURFACE LOW IS DEEPENING
ACROSS THE SOUTHERN PLAINS IN RESPONSE TO THIS UPPER LEVEL TROUGH
AND THIS WILL BE THE MAIN FEATURE WE ARE WATCHING FOR THE WEATHER
LATE THURSDAY INTO FRIDAY. FOR TONIGHT...THE WEATHER IS PRETTY
TRANQUIL AS LOW LEVEL FLOW BECOMES SOUTHERLY IN RESPONSE TO THE
SURFACE LOW TO THE WEST. LOW LEVEL MOISTURE IS PLENTIFUL ACROSS
THE EAST AND EXPECT PATCHY FOG WILL BE POSSIBLE ONCE AGAIN LATE
TONIGHT. MADE MINOR CHANGES TO THE HOURLY TEMPERATURE AND DEWPOINT
GRIDS TO ACCOUNT FOR CURRENT TRENDS WITH THE REST OF THE FORECAST
ON TRACK.

05/MA


&&

.AVIATION...
06Z TAF DISCUSSION.

HAVE CONTINUED THE TREND OF MENTIONING IFR VIS AT MGM/TOI EARLY
THURSDAY MORNING. THE HIS RES MODELS ALSO LOOK VERY SIMILAR TO
YESTERDAY MORNING BUT SLIGHTLY MORE MOISTURE...SO ADDED BKN004
CEILINGS. KEPT THE MVFR CEILINGS AT TCL ALSO IN THE MORNING
WITH PATCHY MVFR FOG ELSEWHERE.

SURFACE HIGH PRESSURE SLOWLY WEAKENS AND SHIFTS NORTHEAST WHILE A
STRONG COLD FRONT TAKES SHAPE OVER THE PLAINS. THIS WILL ALLOW
WINDS ABOVE THE SURFACE TO INCREASE OUT OF THE SOUTH OVERNIGHT.
THESE WINDS SHOULD REMAIN BELOW ANY LLWS CRITERIA BUT MOISTURE
TRANSPORT WILL BEGIN. SOME OF THE HI-RES MODELS ARE INDICATING
MORE WIDESPREAD CLOUDINESS DEVELOPING TOWARD DAYBREAK AND THIS
TREND HAS CONTINUED A FEW RUNS NOW. ALTHOUGH THIS DIFFERS FROM THE
NUMERICAL GUIDANCE...WILL LEAN TOWARD MORE PESSIMISTIC CONDITIONS AT
DAYBREAK...ESPECIALLY SOUTH.

THE MOISTURE INCREASES ENOUGH THAT SHOWERS AND THUNDERSTORMS ARE
POSSIBLE ACROSS WEST CENTRAL ALABAMA BY LATE THURSDAY AFTERNOON
INTO THE EVENING. MODEL TRENDS HAVE BEEN SLOWER WITH MORE
ORGANIZED DEVELOPMENT. AT THIS TIME...CONFIDENCE OF OCCURRENCE AT
ANY TERMINAL WAS TOO LOW FOR MENTION...BUT NEXT FORECAST ISSUANCE
WILL LIKELY HAVE SOMETHING AFTER 06Z.

NOTE...THE NATIONAL WEATHER SERVICE WILL BEGIN ISSUING SEASONAL
TERMINAL FORECASTS FOR THE TALLADEGA MUNICIPAL AIRPORT (KASN) IN
TALLADEGA...ALABAMA. THE FORECAST WILL BEGIN OCTOBER 5TH AT 00Z
AND LAST THROUGH AT LEAST THE 23RD OF OCTOBER.

75

&&

.PREV DISCUSSION...
/ISSUED 405 PM CDT WED OCT 1 2014/

THIS AFTERNOON...WE HAVE SOUTH TO SOUTHEAST FLOW IN THE LOWER
LEVELS AROUND A RIDGE EXTENDING SOUTHWARD ACROSS THE NORTHEAST
U.S. FROM EASTERN CANADA. A BLAND ZONAL FLOW WAS PRESENT ACROSS
THE SOUTHEAST U.S. VISIBLE SATELLITE SHOWED ONLY FAIR WEATHER
CUMULUS THIS AFTERNOON AND A CLEAR RADAR. ONE MORE RAIN FREE NIGHT
IS EXPECTED AHEAD OF OUR NEXT SYSTEM WITH ONLY SOME PATCHY FOG
POSSIBLE...MAINLY ACROSS THE SOUTHEAST COUNTIES WITH INCREASING
BOUNDARY LAYER MOISTURE.

ON THURSDAY...WE WILL TRANSITION AHEAD OF OUR FIRST DECENT FRONT
WITH DEW POINTS INCREASING AS GRADIENTS TIGHTEN/ONSHORE FLOW
INCREASES. RAIN CHANCES WILL BEGIN ACROSS THE WEST THURSDAY
DAYTIME AHEAD OF THE SYSTEM BUT THE BETTER ACTIVITY WILL BE DURING
THE OVERNIGHT AND MORNING HOURS ON FRIDAY. AN UPPER SHORTWAVE IS
EXPECTED TO DIG AS IT MOVES ACROSS THE PLAIN STATES THURSDAY WITH
THE UPPER FLOW ACROSS ALABAMA BECOMING LESS ZONAL AND MORE
SOUTHWEST. PERTURBATIONS IN THIS FLOW WILL ALLOW FOR SOME
AFTERNOON AND EVENING TSTORMS. ON THURSDAY NIGHT...THE UPPER LOW
ITSELF DIGS DEEP ACROSS THE CENTRAL U.S. AND WILL AIDE IN
INTENSIFYING A SURFACE LOW AS IT MOVES TO THE NORTHEAST FROM
OKLAHOMA TO THE GREAT LAKES AND DRAGGING A FRONT ACROSS ALABAMA ON
FRIDAY. DYNAMICS REMAIN FAVORABLE FOR A MARGINAL SEVERE WEATHER
WIND EVENT ACROSS THE NORTHERN PORTIONS OF THE AREA IN THE PREDAWN
AND MORNING HOURS FRIDAY AHEAD OF THE FRONT. THERE WILL BE
MODERATE CAPE AND LIFT FOR DECENT UPDRAFTS...ALONG WITH SUFFICIENT
BULK SHEAR OF AROUND 30-4O KTS...WITH FAIRLY GOOD MID LEVEL
WINDS. SEE NO REASON TO MAKE ANY CHANGES TO THE HWO AND CURRENT
AREA LOOKS GOOD. MAIN INSTABILITY MOVES OUT DURING THE
AFTERNOON...AND RAIN COMES TO AN END BY EARLY EVENING ACROSS THE
FAR SOUTHEAST.

GOOD COLD AIR ADVECTION WITH TIGHT GRADIENTS WILL ALLOW FOR
TEMPERATURES TO DROP NOTICEABLY FOR THE WEEKEND. IN THE EXTENDED
THE FLOW TURNS BACK FOR THE FIRST PART OF NEXT WEEK AND
TEMPERATURES REBOUND WITH LOW POPS RETURNING AS WEAK DISTURBANCES
MOVE ACROSS THE STATE WITH A BROAD UPPER TROUGH MOVING ACROSS THE
EASTERN U.S.

08/MK

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     59  86  68  78  48 /   0  20  70  80  10
ANNISTON    62  86  69  78  50 /   0  20  60  80  10
BIRMINGHAM  66  87  71  80  49 /  10  20  70  80   0
TUSCALOOSA  66  89  71  81  50 /  10  30  70  70   0
CALERA      65  87  71  80  50 /  10  20  70  80  10
AUBURN      64  86  69  79  54 /   0  10  40  80  20
MONTGOMERY  66  89  72  82  54 /  10  20  40  80  20
TROY        65  87  71  81  55 /   0  20  40  80  20

&&

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

&&

$$






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.