-- Discussion containing changed information from previous version are highlighted. --
210
FXUS64 KBMX 201855
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
155 PM CDT Fri Sep 20 2024

...New LONG TERM...

.SHORT TERM...
(This evening through Saturday)
Issued at 138 PM CDT FRI SEP 20 2024

This afternoon.

Broad mid-level ridging remains centered over South-Central Texas
today while troughing was evident over the Eastern Seaboard well
to our east. Surface high pressure extended from across Southeast
Canada southwest across the Northeast and Mid Atlantic Regions and
stretched further southwest across much of Tennessee and Lower
Mississippi River Valley Regions. The 20/12z BMX sounding
contained a strong radiation inversion just off the surface
followed by a fairly moist layer up to near 700 mb where a
significant subsidence inversion was evident.

Expect partly cloudy skies this afternoon as dry conditions
persist. Winds will be from the north at 4-8 mph. High
temperatures will range from near 90 in the higher terrain east to
the low 90s west and central.

Tonight.

Broad mid-level ridging will remain centered to our southwest
overnight while surface high pressure will continue to extend
southwest across the area overnight.

Mostly clear skies are forecast overnight with light north to
northeast winds from 2-4 mph. Low temperatures will range from the
low 60s northeast to the upper 60s south and west.

Saturday.

Broad mid-level ridging will become more elongated with time
through the day on Saturday as it extends further to the northeast
over the forecast area. Surface high pressure will continue to
extend into the area from the northeast.

Look for partly cloudy skies on Saturday with another dry day
across the area. Winds will be from northeast to east at 4-8 mph.
High temperatures will range from near 90 in the higher elevations
east to the mid 90s far west.

05

&&

.LONG TERM...
-- Changed Discussion --
(Saturday night through next Thursday)
Issued at 139 PM CDT FRI SEP 20 2024

A period of dry conditions thanks to upper level ridging and
surface high pressure will continue through early next week.
Temperatures will run 7-10 degrees above normal with highs in the
low to mid 90s. Some relief is expected overnight, with lows in
the mid 60s to lower 70s.

By mid week, the upper level ridge shifts to the east as troughing
amplifies over the central CONUS. Alot of model variation in how
that trough evolves and where/if an upper low closes off over the
southern Plains. Additionally, a disturbance in the southern Gulf
moves northward by the end of the week. So, an increase in rain
chances is warranted, although with alot of uncertainty, will keep
chances relatively low.

14

Previous long-term discussion:
(Saturday night through Thursday)
Issued at 349 AM CDT FRI SEP 20 2024

Status quo remains in the long term. Upper level ridging tries to
remain established across the southeast states into early next
week, keeping us in a rain free subsidence zone. By Tuesday, an
upper trough flattens the top of the southeast ridge a bit,
allowing some lift and slightly better low level moisture to get
into central Alabama. Will maintain slight chance to chance POPs
in our area through this time frame.

For Wednesday and beyond, forecast confidence really starts to
nosedive as model spread starts to really increase. And that
includes the tropical Caribbean and Gulf of Mexico. Got to chuckle
at least a little bit at the global model ensemble members that
individually have surface lows of varying strength (including
nothing at all) stretched across just about any position of the
Gulf by this time next week. Suffice to say now is not the time
to bite on any single run of any single model, regarding potential
tropical impacts for us next week.

/61/
-- End Changed Discussion --

&&

.AVIATION...
(18Z TAFS)
Issued at 1152 AM CDT FRI SEP 20 2024

VFR conditions will prevail through this cycle. Expect fair
weather cumulus to become widespread this afternoon with low-level
winds from the north at 3-6 kts. Look for mostly clear skies
overnight with light north to northeast winds from 1-3 kts.
Scattered clouds are expected toward midday Saturday as dry
conditions persist with low-level winds from the northeast to east
at 3-6 kts.

05

&&

.FIRE WEATHER...

-- Changed Discussion --
Rain chances will remain at zero through the weekend as high
pressure takes hold. With temperatures climbing back into the 90s
and a modestly dry airmass in place, RH values should range from
35 to 45 percent each afternoon through Sunday. 20 foot winds will
be variable, at less than 7 mph.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Gadsden     63  92  67  92 /   0   0   0   0
Anniston    65  91  68  92 /   0   0   0   0
Birmingham  68  92  70  92 /   0   0   0   0
Tuscaloosa  67  93  69  93 /   0   0   0   0
Calera      66  91  71  92 /   0   0   0   0
Auburn      68  89  70  91 /   0   0   0   0
Montgomery  68  92  70  93 /   0   0   0   0
Troy        67  90  69  91 /   0   0   0   0
-- End Changed Discussion --

&&

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

$$

SHORT TERM...05
LONG TERM....14
AVIATION...05