626
FXUS64 KHUN 262020
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
320 PM CDT Fri Jul 26 2024

...New NEAR TERM, SHORT TERM...

.NEAR TERM...
(Remainder of this Afternoon and Tonight)
Issued at 200 PM CDT Fri Jul 26 2024

The forecast area remains located in between a trough and
associated vort maxima to our west and an upr ridge to our SE. As
a result, deep layer moisture is streaming northwards between the
pair of features NEWRD into portions of the TN Valley. This has
mostly been concentrated to our west where the main area of active
weather has occurred today. Earlier, a small area of
showers/storms crossed over the TN border area and into our TN
Counties with some brief wind gusts ~30 mph or higher. This
generated an outflow boundary which has lead to some further
development over portions of NE Alabama this afternoon. This
boundary could generate some further activity, especially over
eastern portions of the area the next few hours before moving out
of the area.

Elsewhere, a complex of showers and thunderstorms was located
along the Gulf Coastal Plain, and remnants of this activity may
move across the area late tonight, per the broader suite of hi-res
guidance. Chances for thunderstorms look relatively low, so most
of this activity may be in the form of rain/showers. Fog formation
may occur late tonight, which will be most prone to occur in areas
that receive any rainfall later this evening or overnight.

&&

.SHORT TERM...
(Saturday through Monday)
Issued at 200 PM CDT Fri Jul 26 2024

On Saturday, the upr low will move northward, with most of the
favorable associated dynamics moving away from the area.
Nevertheless, a convergence axis on the SE flank of the upr low
will offer some forcing for ascent and convection especially in SW
portions of the area. Thus, higher POPs (~40-60%) can be found on
Saturday in those areas, with values gradually trailing off to
20-30 POPs in the northeast.

On Sunday, the upr low will become absorbed into the Polar
Westerlies and begin an eastward movement, dragging a weak front
in tow. Moisture convergence will increase ahead of the front,
with PW values largely expected around 2" and wet-bulb freezing
heights climbing to ~14 kft in the deep moist/warm advection
regime. This will create conditions favorable for efficient warm
rain processed and the potential for locally heavy rainfall
capable of producing some instances of flash flooding. The WPC has
issued a Slight Risk for Excessive Rainfall for the 12Z Sun to
12Z Monday period as a result. Flash flooding would be most prone
to occur in urban locations and also areas with poor drainage.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 237 AM CDT Fri Jul 26 2024

The current wet pattern will continue for the start of the long
term forecast. LREF model guidance indicates the continually
presence of tropical moisture through at least Tuesday. This is
seen in PWATs remaining near 2" supporting additional rounds of
afternoon rain and storms Monday, Tuesday, and Wednesday.

Rain and storm chances greatly fall off for the remainder of the long
term as surface high pressure is established in the Gulf of Mexico.
The change to high pressure will suppress rain chances to below 40%
for the remainder of the period while simultaneously ushering in mid
70 dew points from the SSW flow. The drier pattern will allow temps
to steadily rise though the long term forecast to the mid to upper
90s by Thursday. This, coupled with dewpoints in the mid 70s will
reintroduce heat indices nearing or potentially exceeding heat
advisory criteria on Wednesday and Thursday. Forecast trends will be
monitored as we enter the next work week to assess the need for any
heat products.

&&

.AVIATION...
(18Z TAFS)
Issued at 1220 PM CDT Fri Jul 26 2024

The KHSV and KMSL TAF sites are currently being affected by MVFR
ceilings, however, this is only expected to continue to ~22Z based
on latest obs and satellite imagery. Otherwise, a small complex
of SHRA/TSRA along the TN/AL border area will continue to slide
EWRD but will likely miss the KHSV TAF site. A few SHRA may
develop this afternoon leading to VCSH mention in TAFS. Confidence
is not high enough for inclusion of TSRA in the TAFs, however, an
amendment could be needed primarily before 00Z if one develops.
Predom VFR conditions are probable for the period after 22Z,
although patchy fog may occur late tonight along with a round of
SHRA/RA that could reduce vis/ceilings...but there is not enough
confidence to warrant mention in TAFs.

&&

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

$$

NEAR TERM...KDW
SHORT TERM....KDW
LONG TERM....RAD
AVIATION...KDW