261
FXUS64 KBMX 250705
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
205 AM CDT Tue Jun 25 2024

...New SHORT TERM, AVIATION...

.SHORT TERM...
(Today through Wednesday)
Issued at 201 AM CDT TUE JUN 25 2024

A quiet but warm overnight period is ongoing across the Deep South
with the remnant surface boundary currently across southern
portions of our county warning area. Slightly drier air at the
surface currently exists north of the boundary, with lower 60s
dewpoints across far northeast counties. Meanwhile, very muggy
surface conditions exist farther to the south, with mid 70s
dewpoints observed at Demopolis and Troy. With the slightly drier
air in place across the north, we`ll see temperatures drop down
into the mid and upper 60s, while low to mid 70s are likely at
sunrise across the U.S. 80 and I-85 corridors.

Dry northerly flow will exist across much of the atmospheric
profile during the day today, which will also cause our daytime
temperatures to easily rise into the upper 90s to near 100
degrees. The only thing saving us from having to issue heat
advisories is the drier northeasterly flow, which will mix
dewpoints down into the upper 50s to lower 60s during the peak
heating of the afternoon. However, heat indices are still expected
to rise into the 100 to 103 degree range across far western
counties where low level moisture is a tad higher.

Following another warm and mostly clear night tonight, 500mb flow
will become northwesterly during the day on Wednesday as the upper
ridge centers over the desert southwest. An upper level shortwave
trough is expected to move southeast through the Great Lakes
states with the trough axis stretching southward into Kentucky and
western Tennessee. Another 500mb vort max is expected to move
towards our area by Wednesday afternoon, which will help to
develop showers and storms to our west and northwest perhaps in
the form of an MCS. Areas west of I-65 currently have the best
chance of seeing thunderstorm activity during the late afternoon
and into the evening hours. Dry air across eastern Alabama should
limit development in those areas, but guidance is indicating a
fairly good chance of low level moisture persisting across the
west. CAMs this morning are indicating a good chance of scattered
to perhaps numerous storms in the west and northwest, some of
which could be strong to severe at times. We`ll have plenty of dry
air aloft to work with, so if we can get enough lift from
mesoscale boundaries or an MCS we may need to keep an eye on
severe development as temperatures rise into the mid to upper 90s.
Gusty microburst-type winds will likely be the main
hazard. Effective northwesterly shear could also keep some
updrafts going a bit longer as well. We`ll continue to keep an eye
on mesoscale trends to better determine potential hazards.

56/GDG

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 342 PM CDT MON JUN 24 2024

No significant changes in forecast trends this afternoon for the
extended. It might take longer for convection to develop
Wednesday, as the initial focus is to our west. Convective temps
will run in the mid to upper 90s, and will likely need outflow
boundaries to help ignite convection locally. There is around
25kts of bulk shear during the afternoon across portions of the
west. This would help sustain storms, and increase the potential
for wind gusts, if storms can develop.

We flirt with heat indices around 103-105F each afternoon this
week. However, guidance continues to show upper level ridging
building back into the area for the weekend with moisture
remaining elevated. Temperatures will be in the mid to upper 90s
while PWs remain around 2 inches and dewpoints in the low to mid
70s. This would send heat indices into the 105-110F range for
most of the area.

14

Previous long-term discussion:
(Tuesday night through next Sunday)
Issued at 244 AM CDT MON JUN 24 2024

Key messages:

- Rain chances have decreased somewhat and high temperatures have
  increased on Wednesday, but scattered showers and storms are
  still expected with some strong storms with gusty winds possible
  especially in West Alabama.

- Heat indices at or above 105 degrees will be possible Friday
  through the weekend.

Height falls will take place on Wednesday as one shortwave moves
through the Great Lakes and a weaker shortwave in northwest flow
aloft moves through the Lower Mississippi Valley. Due to the
stubborn dry air mass over our area, the higher rain/MCS chances
continue to trend westward, even west of our forecast area. Still,
given the shortwave and height falls and increasing moisture over
West Alabama, at least scattered showers and storms are expected
with higher coverage possible if any cold pools can organize.
Temperatures have trended upward as well, but with the lower dew
points expect heat indices to remain below 105 on Wednesday. Shear
and mid-level lapse rates will be weak, with instability dropping
off as you go eastward into the dry air. But given the dry air
aloft and hot temperatures at the surface, some strong storms with
gusty winds/microbursts will be possible if the storms can get
going and cold pools can form. Will monitor the mesoscale trends
to see if any isolated severe storms can develop.

A positively tilted trough will extend from the Carolinas
southwestward to the Florida Panhandle on Thursday, while ridging
begins to build back to the east across the Lower Mississippi
Valley. Dry air aloft will be advecting in from the northwest as a
surface frontal boundary washes out. Isolated to scattered showers
and storms will be possible especially in our southeast counties
closer to the better moisture. Highs will "only" be in the middle
90s in most locations. Strong subtropical ridging builds back in
over the Southeast Friday through the weekend. This will result in
hot temperatures continuing. Most areas remain dry Friday, but
PWATs increase over the weekend with weak low-level southerly
flow. This means that unlike the previous ridge there will be some
potential for diurnal convection which could impact highs in some
spots. Also, this will result in higher dew points meaning there
will be increasing chances for heat indices at or above 105
degrees.

32/Davis

&&

.AVIATION...
(06Z TAFS)
Issued at 201 AM CDT TUE JUN 25 2024

VFR conditions will continue through the forecast period with
mostly clear skies and light northerly surface winds.

56/GDG

&&

.FIRE WEATHER...

Isolated showers end this evening, with rainfree conditions
expected through Tuesday night, as a front settles to our south.
Drier air arrives behind the front, with minimum RH values of
24-35 percent Tuesday. Overnight RH values recover to above 70
percent tonight and Tuesday night. Better rain chances arrive
Wednesday and Thursday. 20ft winds will become northerly on
Tuesday and westerly Wednesday, at less than 8 mph.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     97  68  99  71 /   0   0  20  40
Anniston    96  70  98  72 /   0   0  20  30
Birmingham  99  74  99  74 /   0   0  30  40
Tuscaloosa  99  73  96  73 /   0   0  40  40
Calera     100  72  99  74 /   0   0  30  30
Auburn      97  73  97  74 /   0   0  20  30
Montgomery  99  71  99  74 /   0   0  30  30
Troy        99  71  99  72 /   0   0  40  30

&&

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

$$

SHORT TERM...56/GDG
LONG TERM....14
AVIATION...56/GDG