National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS64 KBMX 181131
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
631 AM CDT Thu Apr 18 2024

...New AVIATION...

.SHORT TERM...
(Today through Friday)
Issued at 255 AM CDT THU APR 18 2024

Went ahead and updated the northeast to a Dense Fog Advisory with
visibilities at Gadsden and Pell City down to a 1/4 mile. May need
to include the northwest as well, but right only an isolated spot
or two less than a mile here.

16

Previous short-term discussion:
(Today through Friday)
Issued at 110 AM CDT THU APR 18 2024

High pressure currently remains centered over the area this
morning. Meanwhile some low level moisture is working its way
north. Meanwhile an outflow boundary worked down to near the I-20
corridor. All this will result in low clouds and some patchy dense
fog. We will be keeping an eye on the trends to see if any areas
will need a dense fog advisory before sunrise. The high pressure
system will slowly slide south and east during the day. A weak
disturbance will move northeast into the area along the former
outflow boundary left over, near the I-20 corridor. This combined
with the heating of the day, will likely result in some scattered
storms along and north of I-20, perhaps as far south as the I-85
corridor. With the proximity to the high there remains some
subsidence aloft that will keep most of the storms under control
this afternoon. A few of the storms could potentially be strong
with gusty winds at times. Therefore will leave any mention of
widespread severe storms out of the HWO for this afternoon.

As we work into the evening, some of the CAMS are showing a MCS
developing near the Missouri Bootheel and tracking southeast. The
remnants of the MCS will likely impact north Alabama after
midnight, and increased rain chances for areas north of I-20.
Expect the MCS to be in a weakening state as it moves into north
Alabama, and will continue to not highlight any severe threat at
this time. This outflow will leave a boundary across north
Alabama on Friday. A cold front will move into northwest Alabama
Friday morning. It is unclear which boundary will be the focus for
diurnal convection, but there is enough potential instability for
some stronger storms Friday afternoon, mainly along and north of
I-20. However a strong 700 mb subsidence zone may prevent the
development from being widespread. Again with the uncertainty will
leave any mention of severe weather out at this time.

16

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 208 AM CDT THU APR 18 2024

The boundary will continue to shift southward through the night
Friday, stalling somewhere between I20 and I85 in the southern
half of the area. Low level flow south of the boundary will be
out of the south and southwest, while flow north of the boundary
will be from the northwest. This boundary will allow for an axis
of convergence for storms to develop Saturday afternoon, and
through much of the day on Sunday.

Saturday afternoon, the greatest shear will be in areas along and
north of I20, with the greatest instability along and south of
the boundary, along with PW values just shy of the 90th percentile
for this time of year. Scattered showers and thunderstorms are
possible Saturday afternoon through the early night. Wind
profiles are fairly weak through the midlevels, so a few strong
storms are expected. Any activity should weaken through the
evening Saturday, with scattered showers and thunderstorms
expected Sunday, increasing in coverage and intensity through the
morning. The entire area could see rain, but the higher chances
will be around this same boundary. Shear will be much higher
Sunday afternoon, though instabilities are expected to be less
than Saturday.

High temperatures will be near normal in areas north of the
boundary, while areas south of the boundary see temperatures a
couple of degrees above normal. With cloud cover anticipated the
entire weekend, areas north of the boundary could be up to 10
degrees or more below normal on Sunday, with areas south of the
boundary a few degrees below normal.

By Sunday evening, a high pressure developing over the western MS
River Valley will move east, and the weakening front will move
east ahead of that high. Winds will be predominately from the west
Monday through Wednesday bringing moisture to the mid and upper
levels and warm air to the state. The area should remain dry with
the next chance for rain in the general timeframe of Thursday
when a low pressure system is expected to move across Alabama.

Temperatures are expected to rebound quickly, reaching near normal
temperatures by Tuesday, and above normal temperatures in the low
to mid 80s by Wednesday.

24

&&

.AVIATION...
(12Z TAFS)
Issued at 625 AM CDT THU APR 18 2024

Many sites have dropped to MVFR and will transition between MVFR
and IFR. By 15 to 16z most of the MVFR conditions will burn off.
A few showers and storms will be possible across the northern
sites between 21z and 03z, so included a prob30 for these areas.
Will monitor the trends and may need to add another round of
showers/storms by the end of the next cycle of TAFs.

16

&&

.FIRE WEATHER...

Isolated to scattered showers/storms are possible in the northern
half of the area this afternoon, with the best chances north of
the I-20 corridor. Increasing rain chances late tonight for areas
north of I-20. Min RH values 40-55% this afternoon and Friday
afternoon, with 20 foot winds should be light and variable
this morning becoming south 5-7 mph by the afternoon. winds will
be shifting to a more westerly direction on Friday but remain less
than 7 mph. Max RH values tonight will be again right around
100%. Rain chances remain in the forecast through Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     86  62  83  57 /  30  60  50  10
Anniston    85  64  83  60 /  20  40  40  10
Birmingham  85  65  83  61 /  30  40  40  10
Tuscaloosa  85  64  84  61 /  30  50  40  10
Calera      84  65  83  61 /  20  30  40  10
Auburn      83  65  85  65 /  20  20  20  10
Montgomery  85  64  87  64 /  20  10  20  10
Troy        85  64  88  64 /  10  10  20   0

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 9 AM CDT this morning for the following
counties: Blount-Calhoun-Cherokee-Clay-Cleburne-Etowah-Randolph-
St. Clair-Talladega.

&&

$$

SHORT TERM...16
LONG TERM....24
AVIATION...16