749
FXUS64 KHUN 181725
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1225 PM CDT Thu Jul 18 2024

...New AVIATION...

.NEAR TERM...
(Rest of Today)
Issued at 900 AM CDT Thu Jul 18 2024

Surface observations indicate the cold front prompting yesterday
and last nights storms and current cloudy conditions is right on
the door step of NW AL. This cold front will continue SE
throughout the day and provide the lift necessary to trigger
additional rounds of scattered rain and storms. With the support
of daytime heating, showers should pick up around mid morning and
increase in coverage through the afternoon. General storm motion
will be along the frontal boundary with storms propagating from SW
to NE. Slow steering flow and an incredibly moist low level
profile will pose a heavy rainfall and flooding risk for both slow
moving storms and storms that move over the same areas. HIRES
guidance indicates near 1000 J/KG of CAPE this afternoon. With no
significant shear, gusty winds and frequent lightning will be the
primary threats in additions to a low flooding risk. Those
partaking in outdoor activities should make sure to remain weather
aware and have multiple ways to receive warnings.

&&

.SHORT TERM...
(Tonight through Sunday)
Issued at 403 AM CDT Thu Jul 18 2024

Showers/storms remain in the forecast through the short-term, with
medium-high chances daily. Due to the front stalling southeastward
of our area, higher rain chances remain south of the Tennessee
river. Rain chances are forecast to peak during the
afternoon/evening hours, aided by diurnal heating, but are
possible during both the daytime and nighttime hours with multiple
rounds forecast. Lightning, moderate to heavy rainfall, and gusty
winds will be threats with any strong storm that forms through the
weekend. In addition to this, a low end flooding threat continues
to be possible. WPC has placed most of our area in a Marginal
Excessive Rainfall outlook (threat level 1/4) Friday morning into
Saturday morning meaning there is at least a 5% risk of rainfall
exceeding flash flood guidance. Due to the weak shear in place,
severe weather is not forecast at this time. However, we encourage
everyone to check back in for forecast updates as we approach this
weekend.

Highs during this time are forecast to peak in the 80s with
overnight lows in the 60s-70s. Heat indices will continue to
remain below 100, reaching the upper 80s to mid 90s.

&&

.LONG TERM...
(Sunday night through Wednesday)
Issued at 403 AM CDT Thu Jul 18 2024

Sunday evening, an upper level longwave trough will be the main
focus as it extends from the Great Lakes to the southeastern Plains.
A subtropical ridge over the Central Atlantic will keep this
trough in place through the mid week. This will allow the
Tennessee Valley to remain in a favorable environment for multiple
rounds of rainfall as southwesterly flow aloft moves over the
area, bringing PVA. PWATs in the 1.8-2.0" are forecast in the LREF
50th percentile range, which would near or exceed the 90th
percentile sounding climatology per BMX. Any storms that form
during this time will likely be efficient rainfall producers and
bring a continued threat for flooding.

&&

.AVIATION...
(18Z TAFS)
Issued at 1225 PM CDT Thu Jul 18 2024

Scattered TSRA this afternoon will be a threat to VFR conditions
this afternoon. Storms that go directly over the terminal may
temporaily lower ceiling and visibilities but due to low
confidence in timing and coverage, left only VCTS in the TAF.
Conditions should clear after sunset yielding VFR conditions
overnight. Near sunrise tomorrow, a low cloud deck will build in
from the south and likely produce MVFR ceiling through the end of
the TAF period. In conjunction with this, light winds and a very
moist air mass will support fog development near sunrise. Exact
timing and intensity for both visibility and ceiling impacts
tomorrow morning will be refined in future TAF issuances.

&&

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

$$

NEAR TERM...RAD
SHORT TERM....HC
LONG TERM....HC
AVIATION...RAD