Helena, Alabama 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

567
FXUS64 KBMX 031120
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
520 AM CST Tue Dec 3 2024

...New AVIATION...

.SHORT TERM...
(Today through Wednesday)
Issued at 102 AM CST TUE DEC 3 2024

A cold start to the day across the area as a cold front moves
through the area and will provide a secondary wave of colder air.
We should see the clouds begin to work to our east by the
morning. Due to their scattered nature, temperatures really are
not being impacted as cold air advection is the main focus of the
cooling temperatures versus radiational cooling. Behind the front
a strong high pressure system builds in. Despite the almost clear
skies in the afternoon, much of the area will struggle to get out
 of the 40s. With clear skies and light to calm winds, much of
the area will drop into the low 20s to even a few upper teens in
the northeast. On Wednesday, the high pressure system slides south
and east of the area and becomes centered off the East Coast.
Meanwhile, a strong low pressure will swing through the Great
Lakes and drag a cold front to the ArkLaTex area by the afternoon.
We should see clouds begin to build in the west, although the
rain should remain to our west.

16

&&

.LONG TERM...
(Wednesday night through next Monday)
Issued at 217 AM CST TUE DEC 3 2024

Key Message:

- Medium (40-60%) 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.

A rex block will remain over the western CONUS through the end of
the week, with ridging in the northern stream over the Pacific
Northwest and western Canada, and a cutoff low in the southern
stream over the Desert Southwest. Troughing will remain over the
eastern CONUS. Within this trough a deep upper low and associated
surface cyclone will dig into the Great Lakes Wednesday night,
with another surge of Arctic air invading the central and eastern
CONUS. Moisture return ahead of this system and lift from a weak
disturbance in the southern stream will result in light to
moderate rain spreading eastward Wednesday night, with milder
overnight low temperatures. There are some low (20-40%)
probabilities for rain exceeding 0.5" in southwest Central
Alabama, but chances of exceeding 1" are very low (<10%). Rain
quickly exits Thursday morning, with blustery conditions by
afternoon and falling temperatures across the north. Winds
decrease somewhat Thursday night, but still remain elevated at 5
to 7 mph. This results in wind chills falling into generally the
10 to 15 degree range across the northern half of Central Alabama
late Thursday night into Friday morning, and lows in the teens in
the far northern counties. Our new cold weather advisory criteria
for apparent (feels like) temperatures is 15 degrees in the
Birmingham and Tuscaloosa areas and southward, and 10 degrees in
the typically cooler northern and eastern counties. Will monitor
for our first potential issuance of this product (formerly known
as the wind chill advisory but now with a higher wind chill
criteria). Temperatures remain well below normal on Friday with
northerly winds.

A system over the Northeast Pacific eventually breaks down the rex
block over the weekend, dislodging the cutoff low while a longwave
trough amplifies over the western CONUS. Not surprisingly the
majority of ensemble members trend slower with breaking down this
block. Will maintain some low (20%) rain chances Saturday and
Saturday night in deference to the minority of ensemble members
which are quicker. The slower trend will allow temperatures to
climb above freezing prior to any precipitation developing. High
(60-80%) rain chances are favored by the ensembles by the Sunday
night/Monday timeframe along with milder temperatures, but with
increasing spread regarding the details of individual shortwaves.

32/JDavis

&&

.AVIATION...
(12Z TAFS)
Issued at 520 AM CST TUE DEC 3 2024

Some MVFR low level cold air stratus have worked in the northern
portion of the state. Restrictions have made it to BHM/ANB/ and
ASN. Looks like BHM will see several hours, while ANB and ASN may
see these ceilings through 16/17z. After 18z, skies should be
clear with perhaps a few cirrus, especially south. Northerly
winds around 7 kts through 23z, then light afterwards through
Wednesday morning.

16

&&

.FIRE WEATHER...

High pressure remains in control over the region, supporting dry and
chilly conditions. Min RH levels this afternoon and Wednesday will
be in the mid to upper 20s in the southeast to low to mid 30s across
the rest of the area. We should rebound overnight with Max RH levels
above 80 percent. Northerly 20 foot winds around 5 to 7 mph area
expected this afternoon and southwesterly around 5 to 8 mph on
Wednesday. Next chance of wetting rains will be Wednesday night into
Thursday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     44  19  54  41 /   0   0   0  50
Anniston    44  23  55  43 /   0   0   0  60
Birmingham  43  25  54  43 /   0   0   0  70
Tuscaloosa  46  25  56  44 /   0   0   0  90
Calera      46  25  55  44 /   0   0   0  90
Auburn      46  27  54  43 /   0   0   0  60
Montgomery  48  25  58  44 /   0   0   0  80
Troy        49  25  57  43 /   0   0   0  50

&&

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

$$

SHORT TERM...16
LONG TERM....32/JDavis
AVIATION...16