293
FXUS64 KHUN 280449
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1149 PM CDT Wed Aug 27 2025

...New AVIATION...

.NEAR TERM...
(Rest of tonight and Thursday)
Issued at 1033 PM CDT Wed Aug 27 2025

Elevated lift and moisture advection well aloft is generating
high cloud cover across the region this evening. This will tend to
lower a bit overnight as an area of sheared vorticity moves SEWRD
into the region. A few light sprinkles could result mainly in NW
portions of the area later tonight, but dry air in the low/mid
levels will limit chances for any accumulating precipitation to
less than 10%. Otherwise, opaque alto/cirro stratus clouds will
also tend to limit temp decreases overnight with lows expected in
the upr 50s to lwr 60s.

&&

.SHORT TERM...
(Thursday night through Saturday night)
Issued at 1033 PM CDT Wed Aug 27 2025

The large scale pattern will tend to remain in place as a phasing
of vort maxima from the Upr Midwest and the Intermountain West
will help to maintain the NW flow pattern across the mid-
Miss/OH/TN Valley regions. A low-level frontal boundary will
likewise become positioned nearly parallel to the deeper flow
pattern, but will likely setup well to our southwest, keeping more
unstable air out of reach. Thus, this resulted in a need to dust
off the old isentropic analysis to help determine elevated
lift/moisture availability across the area. With that said, the
latest global operational models do not suggest a strongly
favorable situation for significant precipitation, while tending
to maintain marginal lift/moisture and the presence of dry air in
the low/mid levels at times. Another issue is the apparent mild
dry advection that could be ongoing in the low-levels. NBM
guidance and the ensemble suite was slightly more robust in the
portrayal of QPF, but that was still largely relegated to far
western and generally southern portions of the area (Cullman
County probably having the best overall chances). Nevertheless,
given the ongoing discrepancies and inconsistency of important
features (lift and vertical moisture structure), it would appear
that QPF amounts would tend to be around one-quarter to one half
inch at most for locations through Sunday morning. It`s important
to realize there are still scenarios where little rainfall occurs
in the area, so POPs will tend to be relatively low due to the
lingering uncertainties, with our area on the edge of better
moisture/dynamics. The better chances for precipitation will
probably come in two waves, one on Thursday into Friday morning,
and then another on Saturday as a wave of low pressure may develop
near and just to the south of our area.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 1033 PM CDT Wed Aug 27 2025

Extended range model consensus suggests that a mid/upper-level
longwave trough will remain established across eastern North
America from Sunday-Wednesday, with WNW flow aloft of 10-20 knots
expected to persist across the TN Valley.

At the surface, an ill-defined area of low pressure (initially
along the northeastern Gulf Coast) is predicted to gradually
become more organized as it tracks southeastward into the FL
Peninsula by Monday, before turning northeastward into the
southwestern North Atlantic Monday night. Although the gradient
between the low to our southeast and a broad ridge of high
pressure (extending from the Upper MS Valley into New England)
will maintain a light NE flow at times, gradual modification of
the local airmass will support dewpoints returning to the
u50s-l60s from Sunday-Monday night. As a subtle surface trough
(originating off the low to our southeast) shifts westward across
our forecast area Sunday, isolated showers will be possible during
the afternoon/evening hours. A similar feature will bring a
slightly greater coverage of showers (and perhaps a few
thunderstorms) on Monday given the gradual increase in deep layer
moisture and CAPE. However the greatest spatial concentration of
precipitation appears as if it will be in more favorable regions
of upslope flow to our north/east, and POPs in our region will
remain between 10-30%. Highs both Sunday and Monday will range
from the u70s-l80s/E to mid 80s/W, with lows in the l-m 60s.

During the period from Tuesday-Wednesday, low-level southwesterly
flow will gradually increase as a northern stream clipper system
and surface low drop southeastward across the northern Plains and
Upper- MS Valley. This will contribute to further moistening of
the boundary layer and a notable increase in CAPE by Wednesday,
when highs will return to the m-u 80s. Thus, a gradual increase in
the coverage of showers/thunderstorms is expected during this
timeframe (both during the day and at night), and strengthening
mid-level winds may result in a few more organized convective
cells on Wednesday.

&&

.AVIATION...
(06Z TAFS)
Issued at 1149 PM CDT Wed Aug 27 2025

There have been no major changes to previous aviation forecast
reasoning, as overcast cirrostratus will continue to spread
southeastward across the region for much of the TAF period,
providing cigs arnd 20-25 kft. Present indications are that our
region will remain on the northern periphery of an axis of
rain/embedded TSRA that will eventually become established from
portions of KS/OK across the Lower MS Valley and into central AL,
as a sfc low develops south-southeastward over the southern High
Plains. Although probabilities for precipitation remain too low to
include at HSV, a PROB30 group for lgt RA has been included at
MSL from 20Z Thursday-2Z Friday. Any precipitation reaching the
ground will fall from cloud layers with bases btwn 8-12 kft, and
should have little-no impact on visibility.

&&

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

&&

$$

NEAR TERM...KDW
SHORT TERM...KDW
LONG TERM...70/DD
AVIATION...70/DD