136
FXUS64 KHUN 170908
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
408 AM CDT Tue Jun 17 2025

...New NEAR TERM...

.NEAR TERM...
(Today)
Issued at 408 AM CDT Tue Jun 17 2025

A weak surface low is drifting slowly northeastward across
northern AR/southern MO this morning in association with a 500-mb
shortwave trough (traveling around the northwestern edge of a
subtropical ridge centered off the southeastern Atlantic Coast).
To the south of the low, a subtle surface trough/wind shift axis
has initiated the development of several small bands of convection
from the Mid-South region southward into west-central MS.
Although this activity is progressing eastward very slowly, we
have indicated POPs increasing into the 50-60% range west of I-65
before daybreak (but most likely in the 10-12Z timeframe). Across
the remainder of the forecast area, warm/humid conditions will
prevail with temps expected to remain in the u60s-l70s through
sunrise. Light southerly winds at the surface (beneath a SSW low-
level jet of 25-30 knots) have resulted in the development of low
stratus clouds, with very patchy (but locally dense) fog also
noted in portions of northeast AL.

Over the course of the day, the mid-level trough and decaying
surface wave will advance slowly northeastward into the Lower OH
Valley, with the trailing trough predicted to sustain convection
as it begins to spread eastward into northwest AL later this
morning. If low stratus clouds manage to lift/scatter prior to the
arrival of the trough and surface temps can reach the mid 80s,
CAPE of 1000-2000 J/kg will support a marginal risk for strong-
severe thunderstorms given mid-level SW flow of 25-35 knots atop a
low-level jet that will remain in the 25-30 knot range. However,
based on the anticipated speed of the trough (and location this
afternoon), this would most likely occur in eastern portions of
the CWFA. Solutions from the 0Z CAMs do indicate the development
of several organized updrafts (most likely in the form of
multicell clusters), the strongest of which will be capable of
producing locally damaging winds (up to 60 MPH), hail up to 1"
diameter and perhaps a very brief tornado if a low-level
mesocyclone can become established.

&&

.SHORT TERM...
(Tuesday night through Thursday)
Issued at 1049 PM CDT Mon Jun 16 2025

Shower and thunderstorm chances should begin to gradually decrease
after sunset on Tuesday and officially come to an end around
midnight. Low temperatures are forecast to drop to the upper 60s
to lower 70s under mostly cloudy skies. Cloud cover, along with
lingering breezy winds, should deter fog formation.

As the aforementioned upper level trough axis continues to slowly
move eastward, shower and thunderstorm chances continue Wednesday
with coverage and intensity peaking during the afternoon hours due
to diurnal heating. Soils will be saturated throughout most of the
Tennessee Valley, allowing an increased flooding risk with any
storms that move through the area as rainfall rates are expected
to be high with stronger storms. Sufficient instability as well as
shear will allow for strong storms to be possible again with gusty
winds, small hail, and frequent lightning to be the main hazards.
Despite not being officially outlooked for severe weather at this
time, a severe storm cannot be ruled out with the primary threat
of damaging winds.

Wednesday night into Thursday, WSW flow allows drier air to filter
in and limited rain chances through the area as lows drop into the
upper 60s to lower 70s. This break in rainfall will be short-
lived, however, as rainfall once again returns on Thursday as a
cold front, stemming from a parent low pressure system in the
northeast, approaches the area from the northwest. Strong storms
along the front, once again, cannot be ruled out with the primary
concern of gusty winds as well as frequent lightning.

&&

.LONG TERM...
(Thursday night through Monday)
Issued at 1049 PM CDT Mon Jun 16 2025

After the frontal passage Thursday night, dry air filters in from
the northwest. A ridge of high pressure is forecast to build in
from the west this weekend, allowing a warming trend through the
weekend into early next week. Daily high temperatures are forecast
to warm into the low to mid 90s by Sunday and Monday with heat
indices near 100-105 degrees. If trends continue on the track they
are on, heat products may be considered if heat indices are
forecast to exceed 105 degrees. Overnight lows are forecast to
drop into the low to mid 70s, which will not provide much relief
from heat. Along with the heat concern, daily thunderstorm
chances (30% or less) continue- peaking during the afternoon
hours. However, heat will be the primary concern heading into the
weekend into early next week. Those without effective cooling
and/or adequate hydration will likely be affected in addition to
heat sensitive industries and infrastructure.

&&

.AVIATION...
(06Z TAFS)
Issued at 107 AM CDT Tue Jun 17 2025

Lingering light RA (remnants of convection Mon aftn/eve)
continues to dissipate across the region, with VFR conds currently
observed at the terminals. However, as the SSW low-level jet
continues to gradually strengthen, stratus will develop once again
within the moist boundary layer airmass, providing cigs arnd 1500
ft from 9-15Z. Chances for precipitation will begin to increase
shortly before 12Z across northwest AL as a subtle sfc trough
shifts eastward into the region. This feature will sustain
clusters of SHRA/TSRA throughout the day as it progresses
eastward, and PROB30 groups have been included at MSL/12-18Z and
HSV/15-21Z. Although conds will temporarily improve in the wake of
diurnal convection, latest model guidance suggests that another
low stratus layer will evolve across the region this late this
evening.

&&

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

&&

$$

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