717
FXUS64 KHUN 081708
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1108 AM CST Fri Nov 8 2024

...New AVIATION...

.NEAR TERM...
(Rest of Today)
Issued at 953 AM CST Fri Nov 8 2024

Light-moderate NNE flow in the lower-levels will persist across
the TN Valley today, between a pair of consolidating anticyclones
across the northern Great Plains and Hurricane Rafael drifting
westward through the central Gulf of Mexico. In the upper-levels,
light WSW flow (on the order of 15-25 knots) will continue within
the gradient between a 500-mb high centered in the general
vicinity of the northern FL peninsula and an upper low over NM.
Given this configuration, widespread/dense low stratus clouds
along the leading edge of the shallow cool airmass that entered
the region overnight will be very slow to erode across our region,
and although forecast soundings do depict some lifting/scattering
of the layer over the course of the afternoon, this appears
optimistic at this point. Based on the synoptic pattern, we have
included a very low (10%) POP for light drizzle, but the most
significant impact from the clouds will likely be significant
reductions in visibility in our higher terrain locations. If
sufficient breaks in the stratus deck can occur this afternoon,
temps may briefly touch the mid 70s, but downward adjustments to
this portion of the forecast may be required later today based on
trends in cloud cover.

&&

.SHORT TERM...
(Tonight through Sunday night)
Issued at 300 AM CST Fri Nov 8 2024

A potent upper low/trough pattern across the southern Plains will
then traverse NNE into the mid Plains/upper MS Valley heading
into the weekend period. An attendant sfc low will also lift into
the upper MS Valley/Great Lakes areas, as another frontal boundary
approaches from the W/NW late in the weekend period. Increasing
showers, along with a few embedded tstms, are expected to develop
along/ahead of the oncoming front Sat/Sun. With the rapid influx
of moisture out of the SE/S coupled with a weak convergent pattern
along the front, some of the showers/tstms may be heavy at time
late Sat night into Sun.

This should at least provide some much needed for the central TN
Valley, especially along/west of I-65. The front may actually
slow/stall invof the area late this weekend, before eventually
drifting to the SE going into the Veterans`s Day holiday. With the
flow pattern turning more zonal, the influx of slightly cooler
may also be delayed more into the Sun/Sun night time frame.
Afternoon highs in the lower/mid 70s Sat look to trend more in the
upper 60s/near 70F Sun afternoon. Overnight lows may struggle to
fall past the mid/upper 50s as well, given the lingering cloud
cover/rainfall. Sfc winds may also gusts around 20-25 MPH at times
going more into the second half of the weekend period.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 300 AM CST Fri Nov 8 2024

By Veterans Day, the upper level pattern over the CONUS should be
more of zonal orientation, as opposed to the current amplified flow.
An upper low that was part of the western CONUS troughing on
Monday will quickly head eastward across the St Lawrence Seaway.
A surface low under this upper support will have a cold front
extending to the SSW. This front should be moving across the
Tennessee Valley on Veterans Day. Scattered showers and a few
thunderstorms occurring as the front passes in the morning should
end from west to east during the course of the day. Rainfall
totals by Monday should range from one half of an inch over our
eastern areas, to as much as 2 inches for the west. High
temperatures for the day should rise into the lower 70s.

With drier and slightly cooler air finally filtering across the
area, high pressure building in from the NW will result in lows
Monday night falling into the mid 40s to around 50. Under
generally sunny skies, a bit cooler Tuesday with highs in the
upper 60s to around 70. Similar conditions are expected Tuesday
night with lows around 50.

Another storm system now moving over the North Pacific near the
International Date Line should be moving across the Lower-48
during the midweek. It will bring clouds and another chance of
showers for Wednesday into early Thursday. Wednesday appears will
be the last warm day for a spell with highs in the lower 70s.
This system will bring another cold front across the area early
Thursday. High temperatures later that day with a colder airmass
filtering in should range in the lower 60s. For reference normal
high/low temperatures by then are around 64/41.

&&

.AVIATION...
(18Z TAFS)
Issued at 1108 AM CST Fri Nov 8 2024

Recent trends in satellite data suggest that a layer of
widespread, low stratus clouds (currently in place to the north of
a weak cool front) will be very slow to disperse this aftn (if
this happens at all). Nevertheless, based on sfc observations, we
will begin the TAFs with MVFR cigs in the 1500-2500 ft layer.
Although occasional vsby reductions will be possible within
patches of lgt DZ for the remainder of the aftn, we will not
mention this in the forecast attm. Partial clearing of the low
stratus deck may occur very late this aftn/early this evening,
concurrent with an increasing coverage of mid/high-lvl clouds.
Patchy (perhaps locally dense) fog may quickly develop within a
few hours of sunset as this occurs, but due to expectations of a
lgt ENE wind, we will wait before including prevailing vsby
reductions in the TAFs. Lgt SHRA (and related MVFR cig/vsby
reductions) within a strengthening low-lvl WAA regime may begin to
impact MSL/7Z and HSV/9Z, with conds deteriorating quickly by the
end of the forecast period.

&&

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

&&

$$

NEAR TERM...70/DD
SHORT TERM...09
LONG TERM...RSB
AVIATION...70/DD