567
FXUS64 KBMX 161842
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
142 PM CDT Thu May 16 2024

...New SHORT TERM...

.SHORT TERM...
(This evening through Friday)
Issued at 1255 PM CDT THU MAY 16 2024

A tranquil but warm day is ongoing across the region with a brief
period of upper level ridging at 500mb. A weak surface ridge is
also just off to our northwest, producing light northerly winds in
the lower levels. We`ve rapidly warmed at the surface early this
afternoon into the 80s in most locations, with 1000-850mb
thicknesses supportive of highs in the upper 80s, perhaps close to
90 degrees across the far south. Our weather will quickly
deteriorate overnight tonight as a shortwave trough begins to
develop and eject eastward out of the four corners states.
Northwesterly flow aloft will become southwesterly after midnight,
with rapidly moistening conditions aloft. The first of several
upper level shortwave impulses will advance eastward during the
morning hours on Friday, with shower and storm activity expected
to be ongoing across southern and Central Mississippi. These
storms are expected to move across southern Alabama and the Gulf
Coast region, with some uncertainty in terms of the northward
extent of the storms. Following that round of convection,
confidence decreases in terms of what our environment will look
like behind it. Guidance trends are currently depicting a break in
the action by the afternoon hours, with potential re-development
of scattered to numerous showers and storms during the afternoon.
Another more potent shortwave is expected to arrive Friday night,
which will bring the best chance for severe storms as well as
flash flood potential. Storms will likely train over the same
areas as the flow becomes southwesterly across the atmospheric
profile with PWATs progged to rise over 2 inches. The latest
trends with the CAMs this afternoon depict the highest rain
chances a little more to the south, and the Moderate Risk of
Excessive Rainfall was also adjusted accordingly. Based on
mesoscale trends that occur tomorrow, we certainly can`t rule out
being "cut off" from the greatest moisture due to MCS development
and the risk areas going even further south when all is said and
done. Although further updates will be needed, 2-4 inches of rain
remain in the forecast across our southern counties with isolated
higher amounts.

The severe weather risk has also shifted farther south as a
result, with the best moisture and instability across the southern
half of Central Alabama. With all that said, the setup will be
very messy and conditional based on where MCS activity develops
and moves through the next 36 hours. Large hail and isolated
damaging winds will be the main hazards, with an isolated tornado
threat possible across our far southern counties in the Slight
Risk area. More isolated severe storms are still possible
elsewhere, but much less of a chance as you go northward.

56/GDG

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 255 AM CDT THU MAY 16 2024

Friday night through Saturday.

A second wave of southerly moisture works into the area Friday night
into Saturday morning. As the morning progresses rainfall becomes
more widespread ahead of the upper low that will move through early
Sunday morning. The consensus of the models indicate another 1 to
1.5 inches of rain with this swath of rain from generally north of
Birmingham and to the the east. If this heavier band does develop
and falls over the areas that receive the most rainfall on Friday
then flooding may once again be a threat for much of the area on
Saturday. Watches will likely be needed with the afternoon forecast
update.

Sunday through Wednesday.

The upper level low exits most of the area by Sunday morning,
however a few models tries to warp some additional rainfall along
the backside of the low. Will keep in PoPs through the afternoon on
Sunday. Deep-layer ridging is depicted in medium-range & ensembles
thereafter, which supports a period of dry, warm weather that
appears to extend into early next week. Highs in the 90s could be
possible by then. On Wednesday we will begin to see the next system
take shape to our west. A shortwave will ride along that boundary
and clip our northern areas, with generally isolated to scattered
showers/storms. A wetter pattern looks to be shaping up for the end
of next week, but will be discussed over the next few days.

16

&&

.AVIATION...
(18Z TAFS)
Issued at 1241 PM CDT THU MAY 16 2024

VFR conditions will continue through the short-term period and
through much of the overnight hours tonight. SHRA activity is
expected to increase between 09z and 12z Friday morning, with
lowering ceilings to MVFR category. Also added PROB30 for TSRA
with the morning activity as well, and amendments may be needed
during this period to include prevailing TSRA once confidence
increases. Also, IFR ceilings are possible once widespread SHRA
activity moves across most of the terminal sites. Prevailing winds
will be out of the north to northwest this afternoon becoming
light or variable overnight. Southerly to southeasterly winds will
prevail during the day on Friday under 10 knots.

56/GDG

&&

.FIRE WEATHER...

Dry and warm conditions expected today with light northwesterly
20 ft winds. Afternoon minimum RH values remain above 40 percent.
Widespread rainfall and thunderstorms return to the area tonight
through Saturday. Minimum RH values remain well above 50 percent
through Saturday. 20ft winds increase from the southeast Friday at
8-10mph, and become southwesterly Saturday. Drier conditions
return early next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     64  75  64  81 /  30  80  80  90
Anniston    65  77  67  81 /  30  80  80  90
Birmingham  68  78  67  82 /  40  80  80  90
Tuscaloosa  68  78  68  83 /  60  90  70  80
Calera      66  77  67  81 /  50  90  80  90
Auburn      67  78  68  78 /  30  80  80  90
Montgomery  69  81  69  81 /  50  80  80  90
Troy        68  81  68  80 /  40  80  70  90

&&

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

$$

SHORT TERM...56/GDG
LONG TERM....16
AVIATION...56/GDG