546
FXUS64 KBMX 261757
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
1257 PM CDT Sun May 26 2024

...New SHORT TERM, AVIATION...

.SHORT TERM...
(This evening through Monday)
Issued at 1228 PM CDT SUN MAY 26 2024

Today, high pressure will keep rain to the north and west through
the afternoon and evening. Mid level flow will be from the
southwest, with PW values increasing slowly through the day, and
temperatures rising into the lower 90s. With moisture increasing,
heat indices will be in the mid to upper 90s in a few places in
the west and south of Central Alabama.

Tonight, the environment will become better prepped for storms
ahead of a cold front expected to move through the area on Monday,
with the main area of increasing instability, PW, and shear across
the northwestern third of the state, closer to that front. A line
of storms is expected to move east and southeast overnight into
the early morning on Monday. While the storms move through
northwestern Alabama, PW values will be around 2 inches, which is
well above max for this time of year, with instabilities between
2500 and 3000 j/kg. 0-6 km shear will be very strong, values up to
80 kts showing on several models across the northern most
counties, and 0-1 km shear around 30 kts. The storms along this
line may stay strong to severe as they move into the northwestern
counties of Central Alabama around 2 am Monday morning, and then
as they move southeast. Damaging winds and large hail will be a
threat, and with the amount of wind shear present, a tornado is
possible.

As the line moves to the east and south, instabilities should
quickly decrease, and shear should weaken through the morning.
While storms could remain strong, the severe threat will greatly
diminish by the time the storms reach the I20 corridor. Areas
south of I20 may see a strong storm if the line can move into the
area faster Monday morning, otherwise, these areas will see
scattered showers with a few isolated thunderstorms.

This area of activity should be east of the area by around 8 am
Monday morning with the rest of the morning and early afternoon
remaining dry. The afternoon on Monday brings lower confidence.
Almost all CAMs, (outlier is the HRRR) show a lack of convection
developing through the afternoon. Wind shear decreases greatly,
and PW values begin to decrease through the afternoon as the
frontal boundary moves from northwest to southeast through the
afternoon on Monday. Due to a combination of morning activity
across the northern half of the state, as well as drier air moving
quickly into these areas from the northwest, would expect
decreasing chances for severe storms across the northwest through
the afternoon.

However, instabilities across the southeastern half of the state
will be between 3500 and 4000 j/kg and LI values around -9. Wind
profiles show very little strength or turning, though upper level
dynamics show divergence aloft. Right now will advertise severe
thunderstorms with damaging winds and large hail the main threat.
If storms can develop and tap into the right combination of
instability and forcing, severe thunderstorms seem to be a given.
Though models are pessimistic as to much if any coverage across
most of the area. In areas south of I85, there does appear to be
decent consensus of a line of storms developing in the mid to
late afternoon, lasting through the evening. With instabilities so
high, will expect a greater chance for strong to severe
thunderstorms in these areas.


24

&&

.LONG TERM...
(Monday night through next Saturday)
Issued at 340 AM CDT SUN MAY 26 2024

The frontal boundary should be moving through Central AL Monday
evening/night, continuing to support strong to severe storms for a
few hours Monday evening before exiting to our southeast before
midnight.

Drier weather expected Tuesday through the end of the week. Some
guidance tries to hint at a few waves moving through the ridge to
our west Wednesday into Thursday, but confidence isn`t there to
included in the forecast at this time. Most indications are that the
low level ridge that builds in across the deep south suppresses much
of the thunderstorm activity under the northwesterly flow aloft.

As we approach next weekend, the ridge slowly slides to our east,
allowing a few shortwaves to slide through to our north, which will
lead to increasing rain/storm chances Friday night through Saturday,
but timing of these waves is highly uncertain and the forecast is
likely to change in coming days.

25/Owen

&&

.AVIATION...
(18Z TAFS)
Issued at 1228 PM CDT SUN MAY 26 2024

VFR conditions should remain across the area through the late
evening. Moisture will advect into the state with ceilings
dropping into the MVFR category overnight. A line of storms will
move from northwest to southeast through the morning hours, with
little confidence on exact timing of any convection at each TAF
site. IFR ceilings are possible with this activity. Scattered
thunderstorms should start developing again Monday afternoon
through the end of the TAF period.

24

&&

.FIRE WEATHER...

Scattered showers and thunderstorms is expected again late Sunday
night through Monday. 20 foot winds will be from the south to
southwest at 6 to 12 mph today. Min RH values will be near or
above 50 percent through Monday, with overnight recoveries near
100%. Drier air builds in Tuesday through Wednesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     69  88  62  87 /  60  40  10   0
Anniston    71  88  64  87 /  40  40  10   0
Birmingham  72  90  65  88 /  50  30  10   0
Tuscaloosa  72  91  66  90 /  50  30  10  10
Calera      73  90  67  89 /  40  30  10  10
Auburn      72  86  68  88 /   0  50  20  10
Montgomery  74  90  68  89 /  10  50  20  10
Troy        72  89  68  89 /   0  50  30  10

&&

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

$$

SHORT TERM...24
LONG TERM....25
AVIATION...24