135
FXUS64 KBMX 091734
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
1234 PM CDT Thu May 9 2024

...New AVIATION...

.SHORT TERM...
(Today through Friday)
Issued at 115 AM CDT THU MAY 9 2024

Key Messages:

- A Mesoscale Convective System dives southeast into the area
  before sunrise and push southeast through the morning and into
  the afternoon hours. While gradually weakening in the morning,
  it may re-intensify before it exists our southeast counties late
  morning into the afternoon. Damaging winds will be the primary
  risk, with large hail and a few tornadoes being possible as
  well.

- Some thunderstorms may redevelop across North-Central Alabama
  late afternoon into the early evening that will have large hail
  potential, this risk will decrease in the evening as another MCS
  approaches our south-central counties from the west.

- The second MCS appears to track a touch to the north of the
  previous forecast, so the severe chances have increased across
  the southern areas. Damaging winds will be the primary
  risk, with large hail and a few tornadoes being possible as
  well.

We will be watching a MCS that is currently across western TN.
This MCS should dive southeast into the area before sunrise and
push southeast through the morning and into the afternoon hours.
While gradually weakening in the morning, it may re-intensify
before it exists our southeast counties late morning into the
afternoon. There may be a line of showers and storms that develops
as well and will merge with this first area. Highest confidence
right now would be with the MCS to or northwest moving down and
then spreading out. Damaging winds will be the primary risk, with
large hail and a few tornadoes being possible as well, especially
if there is a merge of lines. There will be a brief lull before
the next system moves in.

Conditions are shaping up for a secondary round of strong to
severe thunderstorms late tonight through Friday morning. This
activity will likely develop along the cold front which will be
nearly parallel to I-20 as a mid-level shortwave quickly moves
east across the area. The airmass will still be very warm and
unstable south of the front with dewpoints in the lower to mid 70s
and steep 7.5-8 C/km lapse rates leading to large CAPE profiles
(MLCAPE ~3500 J/kg). Shear values will be amplified by the mid-
level speedmax/shortwave which will result in eff. bulk shear
values around 60 kts. This environment will foster intense
convection to our west which will rapidly grow into a large MCS
with damaging wind potential maximized along embedded bowing
segments as the system moves east, across the southern portions
of Central Alabama early Friday morning. There are questions
regarding how far north the threat extends given the uncertain
position of the front and remnant cold pool from the line of
convection this morning/afternoon which could suppress the
greatest risk to the southern third of the area. Anything that
develops south of the cold front will have the potential to become
severe given the moist, unstable environment. Damaging winds are
by far the primary threat, but intense updrafts may lead to large
hail in the Enhanced risk area.

The cluster of storms will begin to exit the area around 7 AM Friday
morning as the cold front continues to push south through the area,
bringing a much more pleasant airmass to the region.

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 245 AM CDT THU MAY 9 2024

Dry conditions return Friday night as the system exits to our
east. Humidity will be lower on Saturday with highs in the upper
70s to lower 80s under sunny skies. A mid-level ridge will move
across the area over the weekend as an upper-level low transitions
from the Four Corners to the Central Plains. Deep moisture
returns on Monday, with an increasing potential for another
period of rainy and stormy conditions through the early part of
next week as a warm front lifts north across the region.

16

&&

.AVIATION...
(18Z TAFS)
Issued at 1234 PM CDT THU MAY 9 2024

The area is experiencing a break from showers and storms from
this morning with isolated showers and storms across the southeast
third of the forecast area but remaining distanced between ANB and
TOI. Expect scattered clouds across most of the area with winds
returning from the southwest at 4-8 kts. A few showers may develop
across portions of the west and central counties by mid to late
afternoon due to building instability with warming temperatures
and high humidity, but this chance is too low to include at any
terminal. Overnight, another convective complex is forecast to
move east into the area from the west, resulting in increased
clouds with chances for rain and some thunderstorm activity with
best chances across the southwest, expanding eastward with time
through the night and into early Friday morning. Some patchy fog
may develop before sunrise Friday given the recent rains across
much of the area but it is conditional dependent on light winds
and decreasing clouds.

05

&&

.FIRE WEATHER...

Multiple rounds of showers and storms are expected to affect the
area through Friday morning. Rainfall amounts will generally
range from 1 to 2 inches. A drier airmass will return on Friday as
a cold front passes through the area with min RH of 35 to 40
percent on Saturday. 20ft winds will be out of the south-
southeast at 8 to 10 kts.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     63  79  49  77 /  40  20   0   0
Anniston    64  80  52  77 /  50  30   0   0
Birmingham  64  80  54  78 /  50  20   0   0
Tuscaloosa  66  82  55  79 /  70  20   0   0
Calera      64  80  55  78 /  70  30   0   0
Auburn      64  81  57  77 /  70  50   0   0
Montgomery  65  84  57  79 /  80  50   0   0
Troy        66  83  57  79 /  80  70   0   0

&&

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

$$

SHORT TERM...05
LONG TERM....16
AVIATION...05