300
FXUS64 KBMX 260846
AFDBMX

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

...New LONG TERM...

.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...
(Thursday night through next Tuesday)
Issued at 346 AM CDT WED JUN 26 2024

- Hot and increasingly humid conditions are expected this weekend
  into next week, with heat indices at or above 105 degrees at
  times, especially Sunday. Scattered showers and storms will
  also be possible each afternoon.

Subtropical ridging will continue to build eastward into northern
Alabama Friday, while a weakness in the ridge will remain along
the Gulf Coast and up into Central Georgia. Weak low-level flow
will become southwesterly, helping maintain lower 70s dew points.
PWATs look to range from around 1.6 inches in West Alabama to near
2 inches in East Alabama. Scattered showers and storms are
expected to develop with daytime heating, with the highest chances
in East Alabama where the best moisture will be and near the
weakness in the ridge, and near possible remnants of an MCV.
Updraft intensity should be muted by warm mid-level temperatures
(500mb temps near -2C) which may limit lightning activity.
Guidance has trended slightly lower on highs with the ridge not
building in as quick, so heat indices look to remain less than 105
degrees. Subtropical ridging strengthens to around 596 decameters
on Saturday. Despite the strength of the ridge, PWATs at or above
2 inches should still allow for some scattered showers and (weak)
storms to develop, highest chances once again east. With the
moisture, guidance has trended slightly less hot, but with
elevated dew points a few spots could see heat indices approaching
105 depending on the competing factors of increasing Gulf
moisture and dry ground conditions.

Meanwhile a shortwave moving through the Great Lakes will cause a
cold front to sink southward into Tennessee on Sunday. Slight
height falls occur over Central Alabama as the ridge retrogrades a
bit westward. Higher dew points pooling south of the boundary will
result in the potential for heat indices to reach 105 degrees
across much of Central Alabama depending on how quickly convection
initiates in the tropical-like air mass. Latest guidance is
suggesting the lower dew points with the front may slip southward
into our northern counties Monday and Tuesday. This would result
in some reduced rain chances in the north, with a less humid but
still hot air mass. Meanwhile, enhanced dew points along and south
of the boundary will result in the potential for heat indices in
the 105-110 range. Exact placement of this boundary is subject to
change, though. Meanwhile, the ridge looks to build back to the
east Tuesday resulting in increasing temperatures as we go through
the holiday week.

32/Davis

&&

.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...

Moisture and chances for showers and storms increase across West
Alabama today, while RH values in East Alabama will still drop
into the 25 to 35 percent range. Scattered, mainly afternoon and
evening showers and storms are expected Thursday into the weekend,
with the highest coverage in the southeast. RH values will stay
above 45 percent in most areas.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     99  69  93  70 /  30  40  40  10
Anniston    98  71  93  72 /  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  72 /  20  20  50  20
Montgomery  98  73  93  73 /  40  40  60  20
Troy        98  71  93  71 /  40  40  60  30

&&

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

$$

SHORT TERM...56
LONG TERM....32/Davis
AVIATION...56