420
FXUS64 KHUN 180100
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
800 PM CDT Wed Jul 17 2024

...New NEAR TERM...

.NEAR TERM...
(Tonight)
Issued at 800 PM CDT Wed Jul 17 2024

Additional convection is developing upstream across southern KY
into parts of western/mid TN going more into the evening hrs this
Wed. This activity is developing in response to a weak shortwave
dropping southward into the region coupled with a weak frontal
boundary moving SE into parts of the Mid South region. These
additional showers, along with a few embedded tstms, will move
into portions of the central TN Valley late this evening into the
overnight hrs. In additional to occasional lightning, brief heavy
rainfall is possible with some of these showers/tstms. Otherwise,
another seasonal night temp wise is expected into early Thu, with
lows again falling mainly into the upper 60s/lower 70s.

&&

.SHORT TERM...
(Thursday through Saturday)
Issued at 115 PM CDT Wed Jul 17 2024

We remain in an active pattern late this week under the influence
of a broad mid/upper trough over the Ohio/Tennessee Valleys.
Medium to high chances (40-70%) are forecast during this
timeframe, with the highest values each afternoon/evening across
the region. The highest coverage will likely be along and south of
the Tennessee River, the area closest to where a weak front
and/or convergence boundary will be stalled over central Alabama.
The main threat with this activity will be locally heavy rainfall
and lightning which will impact though with outdoor plans. In
fact, hydro issues for localized flash flooding may become a
concern later in the week if we get several days of rainfall. The
higher rain chances and cloud cover will keep the dangerous heat
at bay, however, as high temperatures will actually trend below
normal for mid-July, peaking in the mid/upper 80s each day (about
5-7 degrees below normal).

&&

.LONG TERM...
(Saturday night through Tuesday)
Issued at 329 AM CDT Wed Jul 17 2024

The local forecast area will remain to the east of a mid-level
longwave trough (extending from the Great Lakes into the
northwestern Gulf of Mexico) for much of the extended period, with
initially light SSW flow aloft expected to strengthen by
Monday/Tuesday as the height gradient contracts between a
subtropical ridge retrograding across FL and a developing upper
low over the MO Valley. As this occurs, a weak area of surface low
pressure is expected to evolve across west-central TX Friday
night, which will force the stalled frontal boundary to lift
northwestward through the region once again on Saturday. Precisely
how far north and west the front makes it is highly uncertain at
this time, but regardless of position, we will be either
sufficiently close to the boundary or within the moist warm
sector, and this will promote several rounds of rain and
thunderstorms from Sunday-Tuesday (both during the day and at
night). Although shear may strengthen a bit by Monday/Tuesday,
deep moisture and weak lapse rates will limit storm intensity,
with lightning and locally heavy rainfall the main threats. Heat
Risk will not be a concern through the end of the extended period.

&&

.AVIATION...
(00Z TAFS)
Issued at 625 PM CDT Wed Jul 17 2024

Lingering shra/tsra have diminished/moved east of the area heading
into the evening hrs this Wed, leaving just some mid/high cloud
cover. Additional shra/tsra area possible overnight, as a weak
frontal boundary approaches from the NW, with brief/tempo MVFR
cigs/vis possible in/near any heavier shra. Mid level cigs near
4-5K ft are then expected during the day Thu, with further
shra/tsra possible during the afternoon and a PROB30 group has
been added later in the period.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&

$$

NEAR TERM...09
SHORT TERM....AMP
LONG TERM....70
AVIATION...09