311
FXUS64 KBMX 171129
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
629 AM CDT Sat Aug 17 2024

...New AVIATION...

.SHORT TERM...
(Today through Sunday)
Issued at 246 AM CDT SAT AUG 17 2024

Key Messages:

- Heat Index values up to 108 through the afternoon for a large
portion of the area.

- Heat Index values up to 106 through the afternoon for the southern
third of the area on Sunday.

- Isolated strong to severe storms with damaging winds this
afternoon/evening and again on Sunday.

With the current forecast and consensus of models, we will see an
outflow boundary work into the area around 9 to 10 AM. Not much in
precipitation will accompany the boundary but included isolated
wording to account for any activity across the north and southwest.
After 10 AM, the boundary should be between I-20 and I-85. Looks
like we will see convection across the central and southern
sections late morning/early afternoon. Since the north may not
see much in activity, when a second push comes in late afternoon,
we will likely see some development that will then push south
through the evening hours. This was the original thinking from 2
days ago, so it is a plausible scenario that has some support.
Given the possible 2 rounds, we will return to the forecast of
severe for all of Central Alabama for the afternoon and early
evening. Damaging winds will once again be the main concern. While
hail cannot be ruled out, damaging winds will be the primary
concern for this event. The Heat Advisory has been expanded a
touch to the east for today. Showers and storms may put a damper
on some areas, but dewpoints will only increase and we cold see a
resurgence of the humidity after a storm goes through.

Another MCS will move into the area on Sunday. There is some
discrepancies on the most likely entrance area for the MCS. A few
models drag it through the northern sections and then slide south,
while a few take it across the southern portions of the area. If a
storm does develop it will be severe with winds and hail the main
threats. The best chances for severe will be across the southern
half of the area, but cannot be ruled out anywhere.

16

&&

.LONG TERM...
(Sunday night through next Friday)
Issued at 206 AM CDT SAT AUG 17 2024

A highly amplified pattern for late August will be in place for much
of the week as strong subtropical ridging remains centered over the
High Plains flanked by troughs along the West Coast and over the
eastern CONUS. A long fetch of deep layer northerly flow will allow
a modified Canadian air mass to reach the Deep South. The dry air
mass will still warm efficiently to allow for highs in the upper 80s
to lower 90s, but humidity will be low with cool overnight lows by
August standards. In fact, many of the typically cooler
northern/northeastern locations should reach the upper 50s by
Wednesday morning. The eastern CONUS trough will lift out by the end
of the week but will leave behind a weakness/possible weak upper low
near the northern Gulf Coast. As high pressure reaches the East Coast
and weak wedging develops, low-level flow will become easterly
across Central Alabama, continuing to keep the heat at bay. Some
Atlantic moisture may move back into portions of the area, but the
better moisture looks to remain just south of the forecast area at
this time.

32/Davis

&&

.AVIATION...
(12Z TAFS)
Issued at 625 AM CDT SAT AUG 17 2024

As expected the MCS to our northwest has dissipated with an large
outflow extending across eastern MS. Over the past hour this
outflow has begun to interact with a left over boundary in
southwest Alabama. This is helping to fuel some showers/storms in
this convergence zone that has set up. The main outflow boundary
will be between EET and MGM by 16 to 18z. Looks like we may have
one round of showers and storms in the south late morning/early
afternoon, then a second round develop across the north after 21z.
This round will slide south and could work back into MGM after
3z.

16

&&

.FIRE WEATHER...

A few rounds of showers and storms will move by through Sunday
afternoon. RH values will remain above 40 percent through the
weekend. A dry air mass returns next week, with no rain expected
Monday through Wednesday and RH values from 30 to 40 percent.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     94  71  93  66 /  60  30  30   0
Anniston    94  71  92  67 /  60  50  30  10
Birmingham  95  73  94  69 /  60  40  30  10
Tuscaloosa  95  73  94  70 /  60  50  30  10
Calera      94  73  93  70 /  60  50  30  10
Auburn      93  73  94  71 /  50  40  40  20
Montgomery  97  74  97  71 /  50  30  40  30
Troy        92  72  97  70 /  50  30  40  30

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM CDT this evening for the following
counties: Bibb-Blount-Dallas-Fayette-Greene-Hale-Jefferson-Lamar-
Marengo-Marion-Perry-Pickens-Shelby-Sumter-Tuscaloosa-Walker-
Winston.

Heat Advisory from 10 AM this morning to 9 PM CDT this evening
for the following counties: Autauga-Chambers-Chilton-Coosa-
Elmore-Lee-Lowndes-Macon-Montgomery-St. Clair-Talladega-
Tallapoosa.

&&

$$

SHORT TERM...16
LONG TERM....32
AVIATION...16