329
FXUS64 KHUN 042248
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
548 PM CDT Tue Jun 4 2024

...New AVIATION...

.NEAR TERM...
(Tonight)
Issued at 234 PM CDT Tue Jun 4 2024

Showers with a low chance of producing lightning are ongoing in
northeastern AL and southern middle TN. These are forecast to
continue NNE with a low-medium chance of redevelopment behind them
as we move into the late afternoon to early evening hours. With
any redevelopment, lightning chances will increase in response to
diurnal heating. Model soundings have PWATs in the 1.7-1.8" range,
which are meeting or exceeding the 90th percentile sounding
climatology per BMX. In addition to this, DCAPE values are
forecast to be 500-700 J/kg coupled with low level lapse rates
around 7 C/km and around 25 kts of shear. Therefore, our main
concerns later this evening will be heavy rainfall and gusty to
damaging winds.

Tonight, low chances of showers (30% or less) will continue
through the morning hours. However, there will be a period of dry
weather (less than 10% chances) for a large portion of the area
between 23Z-04Z. A series of shortwaves will affect the region
ahead of a cold front stemming from a sfc low pressure system in
the Great Lakes region, reintroducing rain chances early
Wednesday morning. More on that in the short term section below.

&&

.SHORT TERM...
(Wednesday through Thursday Night)
Issued at 234 PM CDT Tue Jun 4 2024

The aforementioned cold front will continue eastward, bringing
continued rain chances ahead of it through Thursday evening. Our
greatest period of concern for this time is Wednesday afternoon
into Wednesday evening, during which instability is increased in
response to diurnal heating after our high temperatures climb into
the mid to upper 80s under scattered cloud cover. Our low level
lapse rates will climb into the 7-8 C/km range, supporting an
increased lightning threat with any storm that develops. Our main
concern at this time is flooding as PWATs continue to be in the
1.6-1.8" range with a potential for training. However, CAMs are
hinting at storms failing to sustain themselves as they try to
push east of I-65 Wednesday night. There is continued disagreement
with the evolution of this system within CAMs, therefore, we have
low confidence in the placement and timing of these storms. Storm
chances decrease behind the cold front Thursday afternoon with
sfc high pressure following behind it and subsequent dry weather.
Low temperatures Thursday night are forecast to drop into the
upper 60s to low 70s.

&&

.LONG TERM...
(Friday through Monday)
Issued at 310 AM CDT Tue Jun 4 2024

Will remain under the influence of northwesterly flow aloft for the
long term period, as Friday still looks dry in the wake of a cold
front. High pressure will build to our northwest during the day, and
afternoon highs will be on the "cool" side topping out in the low
80s. Trends have favored dry weather lasting through Saturday, as the
first of a series of weaker shortwave disturbances has slowed down,
remaining west of the area until Sunday morning. Temperatures will be
similar on Saturday, topping out in the low 80s as clouds begin to
gradually increase from the west into the evening hours. The
aforementioned shortwave will help bring better moisture to the area,
but will likely remain rain free until Sunday when a stronger
trough digs into the Midwest, and rich Gulf moisture increases ahead
of a cold front. Models diverge a bit at this range, but right now it
looks like we will see at least low chances (20-30%) for rain and
storms Sunday through Monday, though questions remain on if this will
be one round or multiple depending on the evolution of the trough and
associated front. Highs will remain near the mid 80s through Monday
with lows in the 60s each night.

&&

.AVIATION...
(00Z TAFS)
Issued at 548 PM CDT Tue Jun 4 2024

The only threat to VFR conditions throughout the duration of the
TAF period will be a low cloud deck moving in near sunrise
Wednesday morning. The low cloud deck will likely yield several
hours of MVFR ceilings at both terminals from just before sunrise
likely eroding by mid morning. VFR conditions should prevail
aside from with with generally SSW winds through the duration of
the TAF period.

&&

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

$$

NEAR TERM...HC
SHORT TERM....HC
LONG TERM....25
AVIATION...RAD