Scottsboro, Alabama Weather Forecast Discussion

741
FXUS64 KHUN 230409
AFDHUN
Area Forecast Discussion
National Weather Service Huntsville AL
1109 PM CDT Mon Sep 22 2025
...New AVIATION...
.NEAR TERM...
(This Evening through Tuesday)
Issued at 1045 PM CDT Mon Sep 22 2025
In the mid/upper-levels, a low-amplitude shortwave trough will
continue to shift eastward and away from the region this evening,
with winds aloft expected to veer to WNW and remain in the 20-30
knot range in the wake of this feature. A distinct vorticity
maxima will travel cyclonically across the OH Valley (and through
the trough axis) with this disturbance likely responsible for
ongoing rain/thunderstorms extending from Middle TN into the Upper
OH Valley.
Well to our northwest, a broader, positively-tilted longwave
trough extends from southeastern Canada into the central Rockies,
with the east-southeastward movement of a vort max in the base of
this trough inducing the development of a surface low (initially
across the southern High Plains) into western OK. As this occurs,
a warm front arcing east-southeastward from the low into the Mid-
South region will become the focus for renewed development of
convection across eastern AR/western TN/northern MS perhaps as
early as 2-4Z, but more likely during the early morning hours
Tuesday. As a 20-25 knot low-level jet begins to veer to the WSW
in the wake of the downstream shortwave trough (moving away from
the TN Valley), this will provide a favorable orientation for
expansion of rain/thunderstorms eastward into our CWFA prior to
sunrise. Due to the complex nature of the scenario and vastly
different solutions offered by recent model guidance, we will
maintain our highest POPs across the northwestern half of the
region where confidence in impacts is highest. However, this
regime may eventually encompass the entire forecast area by
sunrise. Given the combination of weak nocturnal instability and
modest deep-layer shear, brief wind gusts up to 40 MPH, lightning
and locally heavy rainfall will be the most significant concerns
with the storms. Otherwise, an abundant coverage of mid/high-
level clouds will keep overnight temps in the 65-70F range, with
development of spotty fog possible in locations that received
rainfall earlier today.
Present indications are that rain and thunderstorms will be
ongoing across the region early tomorrow morning, but should
slowly dissipate during the late morning/early afternoon timeframe
as the the surface low (initially across western OK) begins to
migrate northeastward, drawing the warm front northward into TN.
Although an isolated warm sector shower or thunderstorm will be
possible across our region tomorrow afternoon as thinning clouds
permit some destabilization (temps warming into the m-u 80s), we
will keep POPs low due to weak subsidence induced by a mid-level
ridge.
&&
.SHORT TERM...
(Tuesday night through Thursday night)
Issued at 1045 PM CDT Mon Sep 22 2025
Latest model data suggests that a positively-tilted longwave
trough will extend from a closed low (over the Great Lakes)
southwestward into the central High Plains at the beginning of the
short term period. A vort max embedded within the base of the
trough (initially across western KS) is predicted to track
eastward across the central Plains and into the Lower OH Valley
from Tuesday night-Wednesday night, but will likely become
absorbed in the circulation around the anchoring closed low to its
north. For this reason, little (if any) further development of
the related surface low is predicted as it shifts northeastward
from the Mid- MS Valley into the eastern Great Lakes by 12Z
Thursday.
It still appears as if development of thunderstorms will occur
south of the surface low (across central/eastern portions of OK)
tomorrow afternoon, which could potentially evolve into a small
MCS that may split into two distinct portions tomorrow evening.
Although the northern portion of the MCS may tend to dissipate as
it progresses southeastward across northern AR and into western TN
early Wednesday morning, some residual light rain may spread as
far east as northwestern AL prior to 12Z and we will indicate a
slightly higher POP in this portion of the forecast area. There
are also indications that a few showers and thunderstorms may
develop across northern MS/western TN as the southwesterly low-
level jet begins to strengthen into the 20-25 knot range once
again before sunrise, which would also justify a slightly higher
POP in the west.
Although some showers will be possible for much of the morning
Wednesday, a surface trough trailing southwestward from a low over
the OH Valley low will provide an increase in the coverage of
convection to our northwest by mid/late afternoon, with this
regime expected to spread slowly southeastward though our region
Wednesday evening-early Thursday morning. With mid-level WSW flow
expected to strengthen into the 30-40 knot range, deep-layer shear
will be conducive for organized multicell clusters with an
attendant risk for damaging winds/large hail and perhaps a brief
tornado. However, preceding clouds and rain (Wednesday morning)
may have some impact on instability later in the afternoon,
resulting in uncertainty in the overall risk for severe storms.
Given very high PWAT values of 1.8-2", locally heavy rainfall and
flooding will also be a concern during this timeframe.
In the wake of morning precipitation Thursday, the local airmass
may destabilize once again, prior to the arrival of a cold front
Thursday afternoon. Should this occur, another round of showers
and thunderstorms may evolve along the front (primarily impacting
the southeastern half of the forecast area). Mid-level winds will
remain sufficiently strong to support a limited risk for large
hail and damaging winds should this occur. Precipitation will end
across the southeastern portion of the forecast area early
Thursday evening, with lows Friday morning falling back into the
u50s-l60s.
&&
.LONG TERM...
(Friday through Monday)
Issued at 1045 PM CDT Mon Sep 22 2025
A bit of a welcomed pattern change will arrive Friday in the wake
of a cold front as high pressure moves in from the west and
enforces a cooler and drier airmass in time for the weekend. There
will be low chances (10-20%) for lingering showers east of I-65
Friday morning but most of the activity should be clear of the
area by then. Cloud cover should thin from west to east throughout
the day and northerly flow will help keep temps in the upper
70s/lower 80s through the afternoon. The remainder of the weekend
looks to be cool and dry with highs in the low to mid 80s and lows
near the 60 degree mark. With plenty of sunshine expected, it
should be a great early fall weekend for any outdoor activities.
&&
.AVIATION...
(06Z TAFS)
Issued at 1109 PM CDT Mon Sep 22 2025
Coverage of showers and thunderstorms is expected to slowly
increase throughout the early morning hours, as a subtle warm
front lifts slowly northward through the region. Although TEMPO
groups have been included for the period from 10-14Z, these may
need to be moved up by a few hours if dictated by trends in radar
data. Outside of convection, VFR conditions will prevail with
patchy mist and fog also possible btwn 9-13Z. In the wake of
morning precipitation, a sct Cu field will redevelop by 23/16Z,
with the greatest coverage of showers/storms expected to be
focused to our north (across Middle TN) tomorrow aftn. Dry
conditions will continue Tuesday evening, with lgt/vrbl winds.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&
$$
NEAR TERM...70/DD
SHORT TERM...70/DD
LONG TERM...25
AVIATION...70/DD

NWS HUN Office Area Forecast Discussion