453
FXUS64 KBMX 220227
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
927 PM CDT Fri Mar 21 2025

...New SHORT TERM...

.KEY MESSAGES...
Updated at 927 PM CDT FRI MAR 21 2025

 - Low (Level 1 out of 5) risk of severe storms Sunday night, with
   a main threat of damaging winds.

 - Elevated fire weather conditions may develop through the
   weekend, as fuels become dry at the surface and lower level
   winds increase.

&&

.SHORT TERM...
(Tonight through Sunday)
Issued at 927 PM CDT FRI MAR 21 2025

No big changes planned to short term forecast at this time.

/61/

Previous short-term discussion:
(This afternoon through Saturday)
Issued at 1129 AM CDT FRI MAR 21 2025

Following a chilly morning in which most locations dropped to the
freezing mark or just below, we`re warming into the upper 40s to
lower 50s as we approach midday. Central Alabama is currently
wedged in between two 500mb shortwaves, with a ridge axis building
as far north as the southern Great Lakes. At the surface, high
pressure is almost directly overhead and winds will be greatly
reduced from the gusty conditions we experienced on Thursday. The
current short-term forecast is in good shape with highs on track
to rise into the mid 60s areawide. As the surface ridge moves to
our southeast late this afternoon and into the evening hours,
winds will begin to shift out of the southwest. At the same time,
we`ll see a very weak upper shortwave scoot eastward which will
bring some higher cloud cover across our northern counties between
7pm and midnight. Otherwise, mostly clear conditions are expected.
Tonight will probably be one of those nights where some locations
will be able to decouple the boundary layer and others will stay
mixed. Guidance is indicating that winds may stay around 5mph
during the overnight, especially along and north of I-59. For now,
I`ve lowered temperatures at our normally cooler valley locations
such as Gadsden, Talladega, and Sylacauga into the mid to upper
30s, while most everyone else will be in the lower 40s. We could
also see temperatures drop very quickly as the boundary layer
decouples, but quickly rise again if winds increase to allow
mixing. In those colder sheltered valleys, we`ll have another
good chance of frost formation and that`s been added to the
forecast accordingly. It won`t be widespread enough for a Frost
Advisory, but certainly notable to mention. In terms of an overall
temperature forecast, it will be a challenge tonight.

A nice warm-up will come during the day on Saturday with mainly
westerly flow at the surface and zonal flow aloft. With dry air
remaining in place, we`ll likely see good surface mixing Saturday
afternoon with dewpoints dropping into 30s and upper 20s. Winds
will likely be elevated as well, so I decided to undercut NBM
guidance on dewpoints while increasing surface winds and high
temperatures as well. Manual adjustments such as these has tended
to verify more often than not so far over the last month. Through
the weekend, Fire Weather parameters may become a concern as
ground moisture begins to dry out.

56/GDG

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 200 PM CDT FRI MAR 21 2025

Models continue to trend to a weakening line of storms as the
front moves into Alabama as it encounters a relatively drier
airmass. Otherwise no significant changes to the discussion below
in regards to the forecast.

16

Previous long-term discussion:
(Saturday night through next Thursday)
Issued at 255 AM CDT FRI MAR 21 2025

A shortwave trough and associated occluding surface low will move
eastward from the Upper Midwest to the Great Lakes Sunday and
Sunday night. Weaker troughing/cyclonic flow aloft will move into
northern portions of Central Alabama Sunday night while some
subtropical impulses move along the Gulf Coast. Breezy SSW winds
appear to stay just below wind advisory criteria Sunday but will
aid warming, while the air mass remains fairly dry over much of
Central Alabama through the afternoon. Showers and storms will
develop off to our northwest along the positively tilted cold
front trailing southwestward from the occluding low. Dew points in
Central Alabama will be mainly in the 50s to near 60F. Cold
temperatures aloft will still contribute to MUCAPE values around
500 J/kg, but weakening of the convective line is expected as it
moves in from the northwest. Low-level flow will be weakening and
veering with time, becoming parallel to the front. Therefore, only
expect a low (level 1 out of 5 risk) of severe storms, with a
main threat of damaging winds. Will keep an eye on the hail threat
given the lapse rates, but given the weak instability think hail
would be mainly sub-severe. The tornado threat, while non-zero
given the SRH, appears very low at this time since SRH will be
decreasing over time with veering winds as the 60F dew points
move in.

Showers and storms linger into Monday morning in the southern
counties before drier air moves in. Central Alabama will be under
northwest flow aloft for much of the next week between a western
ridge and eastern trough. A weak clipper system appears to pass by
to our north on Tuesday. This will pull the stalled front to our
south northward resulting in warmer temperatures for Tuesday,
followed by slightly cooler temperatures Wednesday as it moves
back to the south. Low but non-zero rain chances may materialize
with this weak system Tuesday night. There is some ensemble spread
in temperatures for the latter half of the week due to
uncertainty in the position of the leftover front.

32/JDavis

&&

.AVIATION...
(00Z TAFS)
Issued at 653 PM CDT FRI MAR 21 2025

VFR conditions are forecast across central Alabama over the next
24 hours. There could be some scattered fair weather cumulus
clouds after about 15Z. Otherwise, clear skies.

/61/

&&

.FIRE WEATHER...

RH values are currently below 25 percent areawide this afternoon
with southwest winds at 5 to 7 mph. By Saturday RH values will
drop to 25 percent or lower once again, with increased westerly
20ft winds between 8 and 12 mph. Transport winds Saturday
afternoon will also greatly increase from the west- northwest
between 10 and 20mph, with higher speeds across eastern and
northeastern Alabama. Fire danger is expected to be elevated
Sunday afternoon with RH values in the 25 to 30 percent range and
increasingly gusty 20ft winds at 10 to 15 mph, before rain moves
in Sunday night. Behind the front RH levels will be in the low 30s
on Monday and in the low 20s to low 30s on Tuesday, but lighter
winds through midweek.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     34  72  39  78 /   0   0   0   0
Anniston    38  73  43  78 /   0   0   0   0
Birmingham  41  73  47  78 /   0   0   0   0
Tuscaloosa  40  76  47  81 /   0   0   0   0
Calera      39  73  46  78 /   0   0   0   0
Auburn      39  73  46  78 /   0   0   0   0
Montgomery  39  76  45  81 /   0   0   0   0
Troy        37  75  44  80 /   0   0   0   0

&&

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

$$

SHORT TERM.../61/
LONG TERM....16
AVIATION...02