785
FXUS64 KBMX 270851
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
351 AM CDT Thu Jun 27 2024

...New LONG TERM...

.SHORT TERM...
(Tonight through Friday)
Issued at 835 PM CDT WED JUN 26 2024

Well, a tricky forecast this afternoon and evening. Temperatures
were quite hot again with a few places into the low 100s while
most others were in the 90s. Thunderstorms did initiate in western
Alabama with heating of the day and an approaching upper trough.
Outflows from activity in Mississippi also aided in storm
development. A few of these storms produced severe wind gusts over
60 mph and blowing trees down. Much drier and more stable air was
over eastern Alabama, but the storms held on and many places did
get rain and thunderstorms east. No additional severe weather is
anticipated overnight, but more showers and storms are possible. A
fine line of activity was indicated near Memphis this evening.
This was near a surface cold front and a trough aloft. These
features will swing into the area overnight and Thursday. Will
continue the belief that there is an increased signal that the
entire system will be slower to exit. This leads to better rain
chances than initially thought. Lows will be near 70 overnight and
highs 85 to 95 on Thursday.

75

Previous short-term discussion:
(This afternoon through Thursday)
Issued at 111 PM CDT WED JUN 26 2024

Contrary to much of the 12Z guidance, a large coverage of showers
and thunderstorms have already developed across much of central
and eastern Mississippi and into western portions of central
Alabama. Once the cu field began developing this morning, it
didn`t take long for rain to start falling. This activity is being
driven by a large increase in moisture associated with an
approaching trough axis and cold front over the Mid-south region.
There`s currently a moisture gradient over the area, and there`s
still some drier air across the eastern half where dewpoints have
once again mixed down into the lower to mid 60s. However, moisture
will advect eastward with propagation of the trough, so expect
further area-wide development of convection through the afternoon
with the highest chance for rain focused generally along and west
of I-65. This rain should give us some relief from the heat, but
not soon enough as most areas have already reached the mid to
upper 90s. Per RAP mesoanalysis, MUCAPE is around 3000-4000 J/kg
in our west where dewpoints are in the lower 70s. While shear
values are rather weak, some strong downbursts may produce
damaging winds, and storms could also produce torrential downpours
with PWATs around 2".

There`s been an increasing signal of scattered showers and storms
continuing overnight and into tomorrow as the cold front and strong
PVA move southward into the area. Some hi-res models are even
resolving an MCV-like feature over the area early tomorrow
morning which would further support additional rain and
thunderstorms. So luckily, the odds at receiving beneficial rain
seem to be improving for the next 24 hours. The scattered to
numerous showers and cloudy skies will keep temperatures in the
80s tomorrow.

86/Martin

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 332 AM CDT THU JUN 27 2024

Key message:

- Oppressively hot and humid conditions are expected this weekend,
  with dangerous heat possible on Sunday as heat indices rise
  above 105 degrees. A multi-day heat wave is expected to
  continue through much of next week. Best rain chances will exist
  Saturday through Sunday, with scattered showers and storms
  possible each afternoon through the end of the forecast period.

Another prolonged period of oppressive heat will begin this weekend
as the 500mb ridge begins to build and broaden from Texas all the
way east through the Deep South. The big difference in this heat
wave compared to the one we`ve recently experienced will be the
addition of more tropical low-level moisture with dewpoints expected
to remain in the 70s during the afternoon hours. Rain chances on
Saturday will remain across the eastern and southeastern portions of
Central Alabama, with higher PWATs and deeper 700mb moisture
transport from the southwest. Although shower and storm coverage is
expected to be scattered to numerous, temperatures aloft due to the
500mb ridge strengthening to 597 decameters will be quite warm.
Therefore strong to severe storms are not expected at this time.
Where it doesn`t happen to rain, heat indices will rise between 100
and 105 degrees Saturday afternoon as highs top out in the low to
mid 90s. So, even though we may escape Saturday without issuing a
Heat Advisory, all bets will be off on Sunday.

As the ridge continues to strengthen but slightly retrograde off to
our west, a shortwave trough is expected to move through the Great
Lakes states Sunday morning. A cold front will be moving southward
into northern Arkansas and Tennessee during that time, along with
synoptic lift in the form of a 500mb vort max within the
northwesterly flow. Convective development will be likely with
strong surface instability as temperatures rise into the mid to
upper 90s with dewpoints holding in the low to mid 70s. A Heat
Advisory will be needed if current guidance trends hold, but
widespread convective development (potentially in the form of an
MCS) may throw a wrench in those trends if storms move through a bit
earlier. As of now, heat indices Sunday afternoon should easily rise
between 105 and 110 degrees for just about everyone.

The cold front is currently progged to move southward on Monday,
with a fresh fetch of dry air moving in from the north at 700mb. How
far south the dry air at the surface can move southward is still in
question, which will affect locations that may need another Heat
Advisory Monday afternoon. For now, those locations appear to be
along the U.S. 80/I-85 corridors and points southward with plenty of
moisture pooling out ahead of the surface front. Scattered to
numerous showers and storms can also be expected across the southern
half of Central Alabama. The 500mb ridge is currently advertised to
build back in over Deep South through Thursday, with isolated to
scattered showers and storms possible during the peak heating of the
day. As highs top out in the upper 90s each day, we could enter into
a prolonged period where Heat Advisories may be needed for several
days in a row. With this being said, we`ll also have to start
keeping an eye on the dreaded Drought Monitor, with significant rain
chances staying out of reach likely through the end of next week.

56/GDG

&&

.AVIATION...
(06Z TAFS)
Issued at 120 AM CDT THU JUN 27 2024

All sites are currently VFR. MVFR cigs will spread across most of
C AL from the NW after 9z lasting through midday as a surface low
inches SE into the state. There will be chances for SHRA and TSRA
across the area at times as the low drags a frontal boundary toward
the I20 corridor by sunset and a little further SE toward the I85
corridor tonight/Thu night. Overall winds should be light outside
of convection. Some reduced vsbys may occur briefly with heavier
convection.

08

&&

.FIRE WEATHER...

Scattered to numerous showers and storms can be expected today
across much of Central Alabama, but widespread wetting rains are
not expected. Min RH values this afternoon will be much higher
than previous days, in the 55 to 65 percent range. Transport winds
will remain light and variable at times through the afternoon
today. Fortunately, we`re not expecting much in the way of gusty
erratic winds with showers and storms today like what was observed
on Wednesday. Scattered showers and storms will remain in the
forecast for Friday, confined more to the southern half of Central
Alabama. Transport winds are expected to increase out of the
southwest between 10 and 15mph by Friday afternoon.


&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     88  69  92  72 /  50  20  50  20
Anniston    89  72  91  74 /  60  20  50  20
Birmingham  89  73  93  75 /  60  20  40  20
Tuscaloosa  88  72  92  75 /  60  20  40  10
Calera      89  73  93  75 /  60  20  50  20
Auburn      89  73  90  74 /  70  40  60  20
Montgomery  90  73  92  74 /  70  40  60  20
Troy        89  71  92  73 /  70  40  70  20

&&

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

$$

SHORT TERM...75
LONG TERM....56/GDG
AVIATION...08