428
FXUS64 KBMX 042351
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
551 PM CST Wed Dec 4 2024

...New SHORT TERM, AVIATION...

.SHORT TERM...
(This evening through Thursday)
Issued at 551 PM CST WED DEC 4 2024

Divergence associated with a subtle shortwave, plus an associated
lobe of moisture, is resulting in a pocket of rain just to our
west as of 5:50 pm CT. Some radar echoes for the first few hours
this evening will be in the form of virga as top-down moistening
gets underway though, conversely, any activity exceeding 25 dBZ
should result in sprinkles or light shower activity at ground
level. Otherwise, the main batch of rain will scoot across our
area overnight with some lingering early-morning activity possible
from Livingston-Selma-Montgomery-Auburn and points south. Clouds
should then clear from north to south through the course of the
late morning and afternoon. Rainfall amounts will be low, likely
holding below one-half inch (0.50") even for locations that get
the most shower activity. Low temperatures, while still cool, will
be much higher than Wednesday morning. We do not have any
freezing temperatures on the board for tonight.

Another cold front will be pushing across the state on Thursday.
This will result in a north-south temperature gradient, with
north Alabama high temperatures in the 40s and south Alabama
temperatures near 60. The front will also bring breezy
northwesterly winds with gusts near 20 mph. Cold air advection
will send temperatures tumbling Thursday night with a continued
breeze making it feel colder. More on this can be found in the
forecast discussion below.

89^GSatterwhite

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 148 PM CST WED DEC 4 2024

No meaningful changes were made to the long-term forecast. The
primary weather concern will be the cold temperatures at the
beginning of the period which includes wind chill values in the
10s for a good portion of Central Alabama. This is flirting with
Cold Weather Advisory criteria for at least a few hours Friday
morning, and continues to support hard freeze conditions for areas
long and north of I-20/I-22.

Thereafter, wet/unsettled weather returns to the region Sunday
night into Monday (described very thoughtfully below), but
there`s some uncertainty about the complete exit of rain on
Tuesday/Tuesday night. PoPs do not take a complete decline as a
result. Regardless, this should be a widespread, beneficial
rainfall to Alabama which is still amidst varying drought
conditions.

40/Sizemore

Previous long-term discussion:
(Thursday night through next Tuesday)
Issued at 148 AM CST WED DEC 4 2024

Key Message:

- Medium to high (50-70%) chances of wind chills dropping into the
10 to 15 degree range across the northern half of Central Alabama
late Thursday night into Friday morning.

Strong cold air advection will be in place Thursday night as a
1035mb high sinks southeastward, centered over the Ozarks. Winds
will stay up overnight but will begin to drop off around sunrise in
sheltered locations. Low temperatures will drop well into the 20s
with some upper teens in some of the far northern counties. Wind
chills drop near or below 15 degrees across the northern half of the
area, with some values at or below 10 degrees in some of the
northern counties with the cooler advisory criteria. Therefore there
are at least medium if not high chances of needing to issue a Cold
Weather Advisory. Note that hard freeze warnings are no longer
issued, but some far northern counties will reach the old hard
freeze criteria of 20 degrees or colder. A chilly day is expected
Friday with continued northerly winds. Calm winds and very low dew
points will result in favorable radiational cooling conditions
Friday night though some high clouds move in late. Lows will drop
well into the 20s once again.

Ensemble clusters of solutions are coming into much better agreement
with the forecast for this weekend and early next week. Saturday and
Saturday night now look dry with moderating temperatures and winds
becoming easterly and then southeasterly. A kicker trough over the
northeast Pacific will break down the rex block over the western
CONUS. The southwest US cutoff low will eject northeastward across
the Mid-South Sunday night and Monday morning. Moisture transport
from a 45kt LLJ results in high (70-90%) rain chances across the
northwest half of the area by Monday morning. The shortwave will be
outrunning the northeastward progression of the warm sector at the
surface with negligible instability with this lead shortwave. The
cold front will remain off to our west until Tuesday as the upstream
shortwave amplifies into a longwave trough across the central CONUS.
This will result in continued rain chances and mild temperatures,
though moisture appears limited with the frontal passage itself on
Tuesday.

32/JDavis

&&

.AVIATION...
(00Z TAFS)
Issued at 520 PM CST WED DEC 4 2024

A weather system with light rain is expected to scoot across
central Alabama tonight into early Thursday morning. VFR conditions
this evening will give way to MVFR (and potentially a few hours
of IFR for a few terminals) overnight to early Thursday morning,
with VFR/SKC for the afternoon. A light southwesterly breeze this
evening will become northwesterly by early Thursday morning,
followed by ~20 knot gusts from 15z.

89^GSatterwhite

&&

.FIRE WEATHER...

A fairly widespread, but light, rainfall is expected to move
across the area tonight. Accumulations will be light through
Thursday morning. Thereafter, a cold front will move across the
area Thursday afternoon bringing much drier air. 20 ft winds are
forecast north-northwesterly at 5-10 mph with higher gusts. Winds
will be lighter and out of the north on Friday with minimum RH
values 25-30%. We`ll remain stable and dry before soaking rains
return to the region on Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     39  49  19  45 /  50   0   0   0
Anniston    42  51  21  45 /  60   0   0   0
Birmingham  42  50  22  44 /  80   0   0   0
Tuscaloosa  43  52  22  46 /  90  10   0   0
Calera      43  52  23  46 /  90  10   0   0
Auburn      42  56  25  48 /  70  20   0   0
Montgomery  44  57  26  50 /  90  40   0   0
Troy        42  57  27  49 /  80  50   0   0

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...89^GSatterwhite
LONG TERM....32
AVIATION...89^GSatterwhite