-- Discussion containing changed information from previous version are highlighted. --
152
FXUS64 KHUN 101123
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
623 AM CDT Thu Jul 10 2025

...New AVIATION...

.NEAR TERM...
(Today)
Issued at 328 AM CDT Thu Jul 10 2025

Patchy fog has developed across portions of northern Alabama and
southern middle Tennessee early this morning in areas that
received rainfall. Additionally, some light rain showers (and a
few rumbles of thunder) have redeveloped along a residual outflow
boundary. This activity will likely continue at least for the next
couple of hours, before diminishing close to sunrise. Any fog
will also quickly dissipate by mid-morning, resulting in at least
some partly cloudy conditions through the remainder of the
morning. Expect a pretty similar day to yesterday across the
Tennessee Valley as yet another shortwave clips the area, helping
to generate additional rounds of showers and thunderstorms (40-60%
chance). A few of these storms could become locally strong, with
gusty winds the main concern. Additionally, this activity will be
capable of producing locally heavy downpours and thus we will need
to monitor for a localized flash flooding threat in locations that
receive repeated rainfall. The denser cloud cover will keep
temperatures in check today, with highs remaining in the
mid/upper 80s.

&&

.SHORT TERM...
(Thursday through Sunday)
Issued at 938 PM CDT Wed Jul 9 2025

As an upper shortwave trough over the Ohio and Tennessee valleys
shifts to the northeast, a weak, upper ridge moves over the
Southeast. However, ripples of shortwaves look to move over the
Ohio Valley and into the northern portion of the Tennessee Valley
through the period. Additionally, a more potent shortwave trough
is shown to progress over the north-central CONUS and over the
Great Lakes this weekend. At the surface, high pressure will
maintain its hold over the northern/northeastern Gulf as well as
the Appalachians. A surface front may approach the Tennessee
Valley on Sunday, but confidence is currently low whether it will
hold together by the time it would progress over our area.
Overall, expect daily chances (30-50%) of showers and storms to
continue from late week through the weekend, especially during the
afternoon and evening hours.

As guidance shows bulk shear values below 20 knots (really only
around 10 knots) through Sunday, no organized severe weather is
anticipated. However, as is usual for the summer time, with ample
instability in the afternoon will come the potential for some
storms to become strong and produce gusty winds and frequent
lightning. In addition, model PWATs range between 1.4-1.8 inches
Thursday and Friday and increase to between 1.7-1.9 inches this
weekend. To put this in perspective, around 1.8-2.0 inch PWATs are
between the 75th and 90th percentiles when compared with BMX
Sounding Climatology. Thus, showers will be efficient rainfall
producers. This may lead to at least minor flooding concerns if
storms move over the same locations repeatedly, especially by this
weekend.

Highs Thursday and Friday will be a tad cooler, with upper 80s to
around 90 degrees anticipated for most locations. Some spots in
the higher elevations of northeast Alabama and southern middle
Tennessee may see highs in the lower to mid 80s both days. By the
weekend, expect highs to warm into the upper 80s to lower 90s.
Meanwhile, lows in the upper 60s to lower 70s will be common from
Thursday night through Saturday night. Warmer temperatures and
elevated moisture will also result in higher heat indices as well,
with values in the upper 90s to around 103-105 degrees both
Saturday and Sunday (especially on Sunday). Although widespread
Heat Advisory criteria is not forecast at this time, it will still
be hot and caution should be taken if outside. Ultimately, if you
have outdoor plans, please stay weather aware and remember heat,
storm, and flood safety! Make sure to drink plenty of water and
take frequent breaks in the shade. If thunder roars, go indoors!
And, turn around, don`t drown if you encounter flooded roads!

&&

.LONG TERM...
(Sunday night through Thursday)
Issued at 938 PM CDT Wed Jul 9 2025

By the start of the long term forecast high pressure at the
surface and aloft will have made its way west across the FL
Peninsula into the SE CONUS. High pressure will dominate the long
term forecast however we will not reap the the benefits of high
pressure influence (aka subsidence suppressing rain and storm
chances) rather, continued ESE flow will maintain high dew points
in low to mid 70s as well as PWATS just below 2". This moist
environment will combat subsidence from high pressure and amount
to continued medium scattered rain and storm chances each
afternoon through the long term forecast. A lack of forcing will
dissuade any widespread severe chances.

Models diverge slightly on the exact location of high pressure as
we head into the middle of the week. With a warming trend
developing through mid week, the exact location of high pressure
will dictate just how hot we get. Should the high pressure center
be closer to the TN Valley, we will likely be flirting with or
just over Heat Advisory criteria many days next week. Should high
pressure remain slightly further removed, we may not quite reach
the 105 heat index criteria. We will keep a close eye on this
trend as the period draws closer.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 623 AM CDT Thu Jul 10 2025

LIFR conditions due to dense fog will continue for another hour or
so, before dissipating by mid-morning. VFR conditions will
prevail this morning, but medium chances for TSRA may result in a
return to MVFR conditions later this afternoon and evening. Have
added a TEMPO to account for this in the TAFs. AWWs and amendments
may be needed during this window.
-- End Changed Discussion --

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
AL...Dense Fog Advisory until 9 AM CDT this morning for ALZ001>010-
     016.

TN...Dense Fog Advisory until 9 AM CDT this morning for TNZ076-096-
     097.
-- End Changed Discussion --

&&

$$

NEAR TERM...AMP
SHORT TERM....26
LONG TERM....RAD
AVIATION...AMP.24