440
FXUS64 KHUN 041623
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
Issued by National Weather Service Morristown TN
1123 AM CDT Wed Jun 4 2025

...New NEAR TERM...

.NEAR TERM...
(Rest of Today and Tonight)
Issued at 1123 AM CDT Wed Jun 4 2025

An area of weak low pressure over the central Florida panhandle
region continues to slowly move N or slightly NNE this morning.
Some forcing on the periphery of this feature has allowed for a
few areas of widespread mid level cumulus cloud development this
morning (mainly north of the Tennessee River and near/west of the
I-65 corridor).

NBM is already is developing too few clouds in those areas this
morning in guidance. CONSALL seems to be handling the current
conditions better. With increasing forcing moving north into the
area on the west side of the surface low today, currently higher
rain and thunderstorm chances (medium - high in SE portions of
the area). Guidance shows SBCAPE and MUCAPE climbing to between
1000 and 2000 J/KG late this morning into the afternoon hours.
Luckily there is very weak shear with this surface low - not
enough to support organized thunderstorm development). We still
will likely see some thunderstorms this afternoon, especially in
SE portions of northern Alabama. Brief frequent lightning, very
heavy downpours, and some gusty winds to around 30 or 40 mph could
occur in the strongest storms. Given the very weak flow and slow
movement, and PWAT values in place (~ 1.4 inches), we will need to
watch for some pockets of heavier rainfall amounts. Highs should
be cooler than yesterday, especially east of the I-65 corridor due
to cloud cover and precipitation. In those locations, highs will
likely only reach the lower to mid 80s. Further west, mid to upper
80s look more reasonable.

&&

.SHORT TERM...
(Tonight through Friday)
Issued at 414 AM CDT Wed Jun 4 2025

Aforementioned afternoon showers should have dissipated by the
time we go into the mid evening. Dry weather should continue
tonight with low temperatures in the mid/upper 60s.

A frontal boundary extending from the Great Lakes to eastern
Oklahoma and Texas will slowly move eastward. This boundary
nearing the area will result in more chances of showers and
thunderstorms Thursday afternoon. The activity should follow a
diurnal trend, with the convection fading in the evening. Similar
warmth is expected with highs rising into the mid and upper 80s. A
bit milder Thursday night with lows in the mid 60s to lower 70s.

The front to our west will be even closer on Friday. This front
and higher CAPE values of 1200-2000 J/kg, and shear of 30-35kt
could support severe thunderstorms. The new Day-3 convective
outlook has all of area in a Slight Risk. Damaging winds looks to
be the main threat, with hail a lesser one. In addition to strong
and severe convection, a heavy rainfall potential will also be
realized. Precipitable water amounts of 1.7 to 1.9 inches would
support a low flash flooding risk. Before showers begin, high
temperatures Friday should rise into the mid/upper 80s.

&&

.LONG TERM...
(Friday night through Tuesday)
Issued at 1014 PM CDT Tue Jun 3 2025

The beginning of the long term will feature a quasi-zonal pattern
across the regional initially, which will gradually give way to an
Eastern trough pattern by early/mid next week. At the end of
Friday and into the weekend, an enhanced southern stream mid-lvl
jet will move across the region, atop a moisture-laden air mass.
The better dynamics associated with the jet will tend be to our
north, with the jet weakening as it evolves southward across the
region during the weekend. Resulting deep layer shear of ~40 kts
will be supportive of modest storm organization, but which will
also be dependent on necessary CAPEs. In general, ML/SB CAPES
would tend to be supportive, but it`s expected that the
possibility for heavy cloud cover at times and precipitation will
tend to modify or temper instability. Aside from this caveat,
MLCAPES yielding 1500 J/kg amidst the model shear and elongated
hodographs during portions of Saturday/Sunday could generate
severe weather potential, mainly in the form of large hail and
damaging winds. PWs and Spec Humidity values will be supportive of
very heavy rainfall rates with values largely >90th percentile
for much of the weekend based on NAEFS/ECMWF ensembles, while
wind profiles indicate some training of cells could occur along a
W-E oriented thermal boundary. Thus, it`s important not to forget
the potential for heavy rainfall and flash flooding during this
period as well.

The thermal boundary/front will tend to sag slowly southwards
through the period, with better thermal forcing to our south
probably on Monday and afterwards. Nevertheless, the continuation
of rich low-level moisture and diurnal heating (combined with
uncertainty on the southward extent of movement of the boundary)
will lead to a continuation of POPs into early next week.

&&

.AVIATION...
(12Z TAFS)
Issued at 613 AM CDT Wed Jun 4 2025

VFR weather is forecast into the early afternoon, as a SE flow
continues across the Tennessee Valley. This flow will bring deeper
moisture across the area as we go into the late morning. The
moisture and strong daytime heating could result in isolated to
scattered showers/thunderstorms this afternoon. Given that more of
the models were showing this wetter trend, have added a PROB30
for -TSRA for both terminals this afternoon. KHSV will have
somewhat higher odds of receiving rainfall today. Shower activity
should fade after sunset, with VFR weather expected this evening.

&&

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

$$

NEAR TERM...KTW
SHORT TERM....RSB
LONG TERM....KDW
AVIATION...RSB