530
FXUS64 KBMX 260702
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
202 AM CDT Wed Jun 26 2024

...New SHORT TERM, AVIATION...

.SHORT TERM...
(Today through Thursday)
Issued at 158 AM CDT WED JUN 26 2024

Key messages:

- Rain chances will return today, along with the opportunity for
  strong to severe storms across the western half of Central
  Alabama this afternoon through the early evening hours. Gusty
  downburst-type winds will be the main hazard.

- Very hot temperatures will moderate, at least temporarily
  through Thursday returning closer to normal.

Following the blast furnace of Tuesday in which several locations
hit the 100 degree mark, we`ll start to trim back on high
temperatures over the next couple of days. We`ll even add in some
rain chances into the mix (which we greatly need) but we`ll have
to keep an eye out for a few strong to severe storms across
roughly the western half of Central Alabama during the afternoon
and early evening hours today.

Looking out the window this morning, the most notable feature
present is the MCS across the bootheel of Missouri moving
southward into western Tennessee. As expected, this feature will
continue moving southward and eventually decay as it approaches
northern Alabama. Outflow boundaries are expected to move
southward out ahead of the old MCS and will be an additional
trigger for storm development later today. 500mb flow has shifted toward
the northwest as the ridge builds over the desert southwest. An
upper level shortwave will dive southward today and provide
synoptic lift, coupled with decent shear aloft and strong
instability at the surface. There`s a good chance that another MCS
will develop somewhere in the vicinity of eastern Arkansas and
northern Mississippi this afternoon. If an MCS doesn`t fully
develop, we`ll at least see scattered to numerous storms which may
become more organized clusters through the late afternoon and
early evening hours.

Best available moisture coupled with strong surface heating will
exist across the western half of Central Alabama, especially
across the far western counties. Some of the CAMs are suggesting
the possibility of temperatures warming into the mid to upper 90s
before storms start to develop, producing SBCAPE values between
3000 and 4000 J/kg. With dry air aloft, DCAPE values will be 1000+
J/kg. Microburst/downburst ingredients appear sufficient for
severe wind gusts with just enough effective northwesterly shear
to keep updrafts sustained longer. The farther east you go, the
more dry air will be present, especially from the surface to
700mb. Although a few strong storms will certainly be possible
along and east of I-65, severe chances will be reduced, along with
overall coverage of showers and storms. Highs today will remain
very hot, but about a degree or two "cooler" than yesterday,
topping out in the upper 90s to near 100 degrees before storms
develop during the afternoon.

Storms are expected to push southward through the evening hours,
with high-res guidance now indicating that most activity will
diminish through the overnight hours. A stray shower or storm
can`t be ruled out as a surface front slowly moves southward into
Tennessee and northern Mississippi, but trends are much drier.
As the 500mb trough axis continues to move slowly southward on
Thursday, drier air will begin to advect into the region from the
north, which will help to suppress rain chances to the south. More
numerous showers and storms are possible across the U.S. 80/I-85
corridors with isolated to scattered convection across the north.
We`ll turn the thermostat down on the blast furnace, as widespread
clouds will initially keep temperatures cooler Thursday morning
before mixing out during the afternoon. Highs will top out in the
lower 90s Thursday afternoon with light northerly surface flow.

56/GDG

&&

.LONG TERM...
(Wednesday night through next Monday)
Issued at 229 PM CDT TUE JUN 25 2024

The breakdown of the upper ridge (or, its retrograde into the
southwestern states) will be fairly brief. After the passage of
the upper shortwave trough and associated convective system
Wednesday night and Thursday, global models bring the upper ridge
center back east of the Rockies from Friday through the remainder
of the long term. This puts central Alabama back into a typical
mesoscale diurnally driven summertime pattern. That means POPs of
40 to 60 percent on days where the ridge center is more in the
southern plains, and 20 to 30 percent on days where the ridge
center edges eastward into the southern Mississippi Valley and
Southeast states. Unless we get more rain than expected in the
short term, then ground conditions will continue to become
increasingly dry enough to support daytime temperatures in the
mid/upper 90s by this weekend into (at least) early next week.

/61/

&&

.AVIATION...
(06Z TAFS)
Issued at 158 AM CDT WED JUN 26 2024

VFR conditions will continue through much of the forecast period.
SHRA/TSRA development will be possible across western Alabama
today, expected to affect KTCL with a potential for prevailing
TSRA between 18z and 00z this afternoon and into the evening.
Storm chances are less at BHM and EET, but still warrants the
inclusion of PROB30 during that timeframe. Storms will be capable
of producing variably gusty downburst-type winds with rapid
reduction of visibility due to heavy rains. Prevailing winds this
afternoon will be from the west between 5 and 10 knots. Storms
will diminish during the overnight hours with VFR conditions and
generally calm winds. Looking into the planning period, MVFR or
IFR stratus may begin to develop after 06z Thursday morning. That
may be included in subsequent TAF cycles.

56/GDG

&&

.FIRE WEATHER...

Hot and dry conditions will continue through tonight. Moisture
begins to increase from the west on Wednesday, but RH values in
East Alabama will still drop into the 28 to 35 percent range.
Chances for showers and storms will return from the west on
Wednesday. Scattered, mainly afternoon and evening showers and
storms are expected Thursday into the weekend, with the highest
coverage in the southeast.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     99  69  93  70 /  30  40  40  10
Anniston    98  71  93  71 /  30  30  40  10
Birmingham  99  73  93  73 /  40  30  40  10
Tuscaloosa  97  72  93  73 /  60  40  40  10
Calera      99  73  94  73 /  40  30  40  10
Auburn      97  73  91  73 /  20  20  50  20
Montgomery  98  73  93  73 /  40  40  60  20
Troy        98  71  93  72 /  40  40  60  30

&&

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

$$

SHORT TERM...56/GDG
LONG TERM....02
AVIATION...56/GDG