Stevenson, Alabama Weather Forecast Discussion

443
FXUS64 KHUN 281804
AFDHUN
Area Forecast Discussion
National Weather Service Huntsville AL
104 PM CDT Sun Sep 28 2025
...New AVIATION...
.NEAR TERM...
(Rest of Today and Tonight)
Issued at 1115 AM CDT Sun Sep 28 2025
North-northeast flow of 10-20 knots in the middle troposphere
will subside over the course of the day, before winds aloft
collapse overnight. This will occur as a weakening 500-mb trough
(over western portions of VA/NC) begins to retrograde in the flow
around a strengthening but narrow mid-level ridge which will
expand from southern IA/northern MO into the northern Mid-Atlantic
states. In the low-levels, light-moderate northeast flow (driven
by a 2-4 mb pressure gradient) will continue across our forecast
area, as we will remain between a strengthening dome of high
pressure tracking eastward across the Lower Great Lakes and TD 9
(which is predicted to develop further as it lifts north-
northwestward through the central Bahamas). Aside from a few fair
weather cumulus, mostly sunny and dry conditions can be expected
today, with highs ranging from the u70s-l80s in elevated terrain
to the mid 80s in the valley. That said, a few low-topped showers
may develop within an upslope flow regime across western NC this
afternoon and spread southwestward across northern GA and into
east-central AL with the prevailing flow in the boundary layer.
Present indications are that this activity will not impact
northeast AL, but a very low (5-10%) POP has been included in this
region due to uncertainty.
Forecast data from the most recent suite of global models and
CAMs suggests that shower activity may persist well into the
evening hours (in the same region mentioned above), and we will
continue to advertise a 5-10% POP for our eastern forecast zones.
Otherwise, clear skies and a diminishing NE wind this evening may
support early development of fog in the valleys of northeast AL
once again, with a minor increase in mid-level clouds (from
E-to-W) by sunrise resulting in warmer overnight lows in the l-m
60s.
&&
.SHORT TERM...
(Monday through Tuesday night)
Issued at 1115 AM CDT Sun Sep 28 2025
Over the course of the short term period, a narrow mid-level
ridge (initially lying across IL/IN/OH) will become more amplified
with time and centered across northern IL. Meanwhile, a remnant
trough to our east will take on a sharp positive tilt and should
extend from the Lower MS Valley east-northeastward into the
southern Mid-Atlantic states for much of the period. Several weak
lobes of vorticity (embedded within the broader trough) will cross
our region from Monday into Tuesday, perhaps providing at least
weak support for the development of a few showers as forecast
soundings suggest that PWAT values will return to the 1.3-1.5"
range (as dewpoints rise back into the l-m 60s) during this
timeframe. Although coverage of any shower activity will be
locally higher both during the afternoon/early evening hours and
in the vicinity of a couple of surface troughs that will travel
westward across the TN Valley during this timeframe, these
features are difficult to pinpoint at this time range. Thus, we
will maintain a low POP (10-20%) in the forecast, with highest
values for the eastern portion of the forecast area. Highs will
range from the u70s-l80s in the east to the m-u 80s elsewhere,
with lows in the l-m 60s.
&&
.LONG TERM...
(Wednesday through Saturday)
Issued at 1025 PM CDT Sat Sep 27 2025
Looking into the long term forecast, there is a more uncertain
forecast, as is common with tropical systems at this time range.
There are a lot of key synoptic features at play that have the
potential to significantly change the impacts felt by the
Southeast. One of these is the aforementioned shortwave trough
over the Northeast and if it is able to "absorb" Imelda and pull
the track eastward before making landfall. Another feature is
Hurricane Humberto, currently a Major Category 5 Hurricane out in
the Atlantic (posing no threat to the CONUS), and whether or not
we may see a Fujiwara interaction. A final feature (at least that
I`ll mention here, although there is no shortage of features worth
discussing, but I`ll leave that to the NHC) is a shortwave trough
pushing across the Southern Plains. Will this become a cut off
low and help push Imelda out to sea, or remain an open wave and
phase with Imelda and the Northeastern trough? Much to analyze in
the coming days!
For now, will keep the forecast with a 10-20% chance of rain for
areas primarily along and east of I-65 for Tuesday and Wednesday.
As a measure of reasonable worst-case scenarios, analyses of the
grand ensemble (100 weather model members) shows that the high-end
scenario would be near 0.75" of rain and wind gusts of 20-25 mph
mid-week. Most likely, only far northeast Alabama will see any
rain and winds will remain mild. That is for us locally; if you
have family or friends in the coastal Carolinas, help them keep
track of the forecast for their area by keeping up with their
local NWS office, the official NHC forecasts, and any favorite
local or national broadcast meteorologists.
Temperatures will take a bit of a dive heading into late this
week, with highs in the low 70s and low temperatures from the
upper 40s to low 50s. This will either be the result of cloud
cover and cooler air pulled southward from Imelda if it lingers,
or the result of a CAD setup with surface high pressure settling
over the Northeast. Either way, late next week will be a good
taste of Autumn for the TN Valley.
&&
.AVIATION...
(18Z TAFS)
Issued at 104 PM CDT Sun Sep 28 2025
Few-sct Cu (with cloud bases btwn 4-8 kft) will continue at the
HSV/MSL terminals this aftn with a NE wind of 5-10 knots. Although
a few lgt-mod SHRA may spread southwestward into portions of
northeast AL late today (and persist through this evening), this
activity should be displaced well to the east of HSV and we will
indicate clearing skies at both airports around 0Z. A sct-bkn
layer of stratocu will return to the region (from E-to-W) prior to
12Z as low-level moisture begins to increase, with this cloud
layer expected to continue thru 18Z.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&
$$
NEAR TERM...70/DD
SHORT TERM...70/DD
LONG TERM...30
AVIATION...70/DD

NWS HUN Office Area Forecast Discussion