-- Discussion containing changed information from previous version are highlighted. --
213
FXUS64 KBMX 232056
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
356 PM CDT Sun Jun 23 2024

...New LONG TERM...

.SHORT TERM...
(This afternoon through Monday)
Issued at 1247 PM CDT SUN JUN 23 2024

The base of a broad, low-amplitude trough is moving across the Ohio
and Tennessee Valleys this afternoon. At the surface, a cold front
is extending from the low near Quebec southwest through Indiana and
towards the Missouri Bootheel. Some isolated showers are ongoing
ahead of the front across parts of Tennessee and Arkansas, but
it`s evident that the ridge is suppressing development. The
center of the ridge is over the Desert Southwest and deep west to
northwesterly flow has developed across Central Alabama. The front
will make gradual progress towards the Gulf Coast region through
tomorrow afternoon as the surface low shifts eastward across New
England.

Well above normal temperatures are set to continue through tomorrow
and, as is typical of any frontal passage in June, a cooldown is not
expected. Highs will reach the mid to upper 90s, and although
dewpoints have already mixed down into the mid 60s this afternoon,
they`re likely not to mix as much tomorrow due to the large increase
in deep-layer moisture that will accompany the front. Dewpoints in
the lower 70s will likely be focused across the southern half of the
area during the hottest part of the day. There will be higher
chances of seeing some heat indices at 105F in those areas, and a
Heat Advisory may need to be coordinated soon.

Additionally, CAMs continue to paint an opportunity for scattered
showers and thunderstorms overnight as the front moves south. Not
a lot of rain, but hopefully enough to wet some areas that have
been drying out after repeated days in the 90s. A few storms may
produce gusty winds, but organized severe weather is not expected
due to poor lapse rates, weak shear, and relatively weak forcing.
Drier air will quickly return across the north during the day
tomorrow, so the increase in moisture looks to be short-lived.

86/Martin

&&

.LONG TERM...
-- Changed Discussion --
(Monday night through next Saturday)
Issued at 244 PM CDT SUN JUN 23 2024

Model guidance continues to trend slightly lower with dewpoints on
Tuesday, as drier air arrives behind a weak front that settles to
our south. This will keep heat indices below 105F despite
temperatures in the mid 90s to 100F. Best rain chances for the
week arrive Wednesday, with a shortwave trough arriving from the
northwest during the day. It slowly shifts southward, with the
focus for thunderstorms activity shifting to south of I-20 on
Thursday. As stated in the previous discussion, alot of
uncertainty this far out regarding MCS development, but this
pattern would support it. Heat returns for the end of the week,
with a more moist airmass remaining in place. This keeps heat
indices around 105F next weekend.

14

Previous long-term discussion:
(Monday night through next Saturday)
Issued at 301 AM CDT SUN JUN 23 2024

Key messages:

- The heat wave continues Tuesday with temperatures near 100
  degrees areawide. Humidity levels have trended downward but heat
  indices may still reach 105 degrees in portions of West
  Alabama.

- Showers and storms may be strong on Wednesday with gusty winds.

- After a slight respite, the heat wave returns Friday through the
  weekend with potential for a prolonged period of heat indices
  near 105 degrees.

While the center of the subtropical ridge will remain centered
over New Mexico and the Texas Trans-Pecos on Tuesday, weak
shortwave ridging will be present over Central Alabama aloft and
at low-levels. An old frontal boundary/dry line like feature will
be draped somewhere near our southern and western borders. With
this feature trending further south and west, have reduced PoPs
for isolated convection developing near the boundary, and also
lowered dew points. The dry air mass and dry ground conditions
will warm efficiently, with air temperatures near 100F across much
of the area. With dew points mixing out more, heat indices have
trended downward but may still reach 105 in parts of West
Alabama. A weak convectively enhanced shortwave in northwest flow
aloft will approach the area Wednesday with weak troughing
developing over the Southeast and PWATs increasing to near 2
inches. Spread in the timing and placement of this feature has
increased in the guidance, with some indications of
slower/westward trend in some of the guidance. PoPs have decreased
slightly in East Alabama where temperatures have increased. Will
continue to monitor for any upstream MCS development with typical
uncertainty regarding where this occurs and any gusty wind
potential with thunderstorm clusters. The trough may linger near
our southeast counties with enhanced rain chances there on
Thursday, while ridging begins to build back to the east over the
Lower Mississippi Valley. Thursday looks like the "coolest" day of
the period with highs in the low to mid 90s.

Strong subtropical ridging builds across the Southeast and
Southern Plains Friday through the weekend while a couple weak
easterly waves move near the Gulf Coast. The heat wave returns for
Central Alabama but PWATs will be higher than the previous ridge,
meaning more humidity and some isolated to scattered showers and
storms. A prolonged period of heat indices near 105 may be setting
up Friday through next weekend and beyond.

32/Davis
-- End Changed Discussion --

&&

.AVIATION...
(18Z TAFS)
Issued at 1247 PM CDT SUN JUN 23 2024

VFR conditions are expected to continue for much of this period. A
weak front will move south through the area overnight resulting in
an increase in cloud cover. Scattered convection along the front
may produce some aviation impacts, but improvement is expected at
all sites towards the end of this period. Sfc winds are from the
west today at 5 to 10 kts with an occasional gust up to 15 kts,
but speeds will decrease after 00Z. Winds take on more of a
northwesterly heading tomorrow morning as the front moves south of
the area.

86/Martin

&&

.FIRE WEATHER...

-- Changed Discussion --
Isolated to scattered showers and storms return tonight as a weak
front drops through the area tonight and tomorrow. Drier air
arrives behind the front. For Monday, minimum RH values will
range from 30-40 percent for much of the area, and 40-45 percent
across the southern third of the area. On Tuesday, minimum RH
values of 24-35 percent are possible. Overnight RH values recover
to above 80 percent tonight, and above 70 percent Monday night.
Isolated storms may be possible across the south and southwest on
Tuesday, with better chances on Wednesday and Thursday. 20ft winds
will be from the northwest Monday and north on Tuesday, at less
than 8mph.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Gadsden     72  97  67  97 /  40  10   0  10
Anniston    73  96  68  96 /  40  10   0  10
Birmingham  76  98  73 100 /  40  10   0  10
Tuscaloosa  75  98  73  99 /  30  20   0  10
Calera      75  98  72  99 /  30  20   0  10
Auburn      73  95  73  97 /  30  30   0  20
Montgomery  75  96  73  98 /  20  30  10  20
Troy        74  97  73  98 /  10  30  10  30
-- End Changed Discussion --

&&

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

$$

SHORT TERM...86
LONG TERM....14
AVIATION...86