Area Forecast Discussion
Issued by NWS Birmingham, AL

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FXUS64 KBMX 242328

Area Forecast Discussion
National Weather Service Birmingham AL
628 PM CDT Sat Mar 24 2018

For 00Z Aviation.


Through Tonight.

Moisture and rain chances will increase through tonight as a
weak frontal system approaches the northern half of Alabama. With
generally zonal upper flow and only a hint at west-northwest flow
the front will not have much of a push into or through the area.
Radar returns have been light across the northern part of the
state today with likely little reaching the ground. Hires models
all in general agreement that moisture will increase over the next
few hours and some of the rain should reach the ground. Not
expecting heavy rain or much thunder. Only have a slight chance of
thunder mentioned in grids. The closest lightning strikes at this
hour are just west of CHA. With cloudy conditions across the
northwest half of the area and very warm readings across the
south, with increasing cloudiness expected there as well,
overnight lows will be much milder tonight. Only 50s in grids will
be across the far north closer to the front.


Sunday through Saturday.

A weak cold front is pushing through the area on Sunday as cold air
damming sets up in the Carolinas. Light rain is possible along the
frontal boundary Sunday morning and afternoon as it pushes to our
south, but coverage isn`t expected to be overly high. Therefore,
will keep 30-40% chance of rain in the forecast. By Sunday night
through the overnight hours and into Monday morning, a backdoor cold
front moves east to west across our area. Moisture return looks to
be minimal, so again, not expected widespread rainfall through
Monday afternoon. Upper level ridging moves through Monday and
Tuesday with the cooler easterly flow keeping temperatures more

A deep longwave trough slides through the Four Corners Region
Tuesday as the center of the high pressure over the Florida
Peninsula gets shifted eastward slightly. This will limit the cold
air damming influence in Central AL and moist southerly flow will
return. A slow moving cold front pushes eastward through the MS
River Valley later Tuesday night and begins to move into the TN
Valley early Wednesday morning. Models have been trending better in
regards to consistency, showing a positively-tilted trough pushing
the cold front through Central AL Wednesday through Thursday. Both
the GFS and EC are having difficulties resolving any specific
surface low development and both keep instability modest through the
period. Overall, expect a slow moving frontal boundary to push
through the area bringing longer-duration rainfall and possibly a
few thunderstorms. Lack of instability and modest lapse rates will
limit any severe potential with this system.

By Friday, the front has moved off to our south and east, ending
rain chances for Central AL. Cooler and dry weather expected on the
backside of the trough as we go into the weekend.



00Z TAF Discussion.

Moist southwest flow through the overnight hours as a cold front
approaches from the northwest. Showers have been slow to develop,
but expect activity to increase in areal coverage during the
overnight hours as the front approaches. Cigs will gradually lower
overnight becoming MVFR across the northern TAF sites between 03z
and 06z, and IFR by 09z. Lower cigs will form later at KMGM and
KTOI. There is a small chance for tstms, but not enough confidence
to include in TAFS. The cold front will weaken as it tracks
southward into central Alabama and become stationary by 18z. The
low levels of the atmosphere will dry out enough across north
Alabama after 15z for the cigs to rise above 3000 feet agl and
shwrs to shift into south Alabama.




Moisture increases this afternoon as a weak front moves into the
region. Isolated to scattered rain chances expected for most of
the area through early this evening, with slightly better chances
in the late night hours tonight. Some reduced visibility with the
rain and low ceilings are possible early Sunday morning. The
front will stall across the area, with low rain chances continuing
Monday. A brief break in rainfall is expected Tuesday, before
another weather system affects the area. There are no fire weather
concerns at this time.


Gadsden     59  71  46  55  47 /  60  30  30  40  20
Anniston    60  72  46  55  46 /  70  40  40  40  20
Birmingham  61  73  50  59  50 /  60  30  30  40  20
Tuscaloosa  63  75  54  62  51 /  60  20  30  30  10
Calera      62  75  50  59  48 /  60  40  40  30  10
Auburn      62  73  47  54  47 /  50  50  50  30  20
Montgomery  64  79  53  62  50 /  40  40  40  30  10
Troy        63  79  53  61  50 /  20  50  40  30  10




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