234
FXUS64 KHUN 070549
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1249 AM CDT Tue May 7 2024

...New AVIATION...

.NEAR TERM...
(Tonight)
Issued at 859 PM CDT Mon May 6 2024

Showers and thunderstorms remain to our north in middle TN at
this hour. Decided to keep a low POP in for our far northern
portions of southern middle TN for the next hour or two as a light
shower may brush these areas. Also decreased cloud cover for
tonight, leaving partly cloudy skies in place. The rest of the
forecast is on track for tonight. Temperatures are currently in
the 70s and will only drop into the upper 60s. Winds have slacked
with sunset, but an increase in pressure gradient will pick them
back up again after midnight with gusty winds arriving after
sunrise. This will deter fog development but with dewpoints
lingering in the 60s, it will make for a muggy night tonight.

&&

.SHORT TERM...
(Tuesday through Thursday)
Issued at 318 PM CDT Mon May 6 2024

Upper level ridging builds into the area tonight behind the
departing shortwave trough axis as it slides east. This should
give us a break from shower and thunderstorm activity later this
evening into Tuesday morning. Winds in most guidance remain between
5 and 10 mph tonight. These winds and cloud cover should keep fog
from forming, despite some clear skies tonight.

As a parent low from a destructive storm system over the Midwestern
states today moves northeast into the Dakota states, A pre-frontal
trough axis moves east ahead of it into the Ozarks and Minnesota
areas. Upper level ridging remains in place well southeast of it
over much of the Tennessee Valley. It does weaken some though
Tuesday afternoon into the evening hours and may allow a weak
shortwave to ride over the top of the ridge into the area.

With a very unstable airmass in place and dry air aloft on
Tuesday afternoon (2500 to 3500 J/KG of MUCAPE/SBCAPE) and DCAPE
values between 1000 and 1200 J/KG, severe storms will be able to
develop if that shortwave is able to move into the area in the
afternoon. Lapse rates aren`t ideal, but they are between 6.0 and
6.5 degrees/km in most guidance. 0-6 km shear is not great, but
enough for some organized cell structure and maybe some supercells
to develop. There is too little helicity in place though for any
tornado threat. However, very large hail and damaging winds look
possible if the shortwave doesn`t fall apart moving into the upper
ridge, which a few models are hinting at. How long this lasts
past the evening hours is a bit of a question mark. However,
believe that we should see a break in the activity later in the
evening hours.

Strong southwesterly flow will develop ahead of an approaching
storm system Wednesday into Wednesday night. This brings very
warm low level temperatures into the area. Ridging and a low level
cap ahead of this develop storm system should limit convection
over Alabama. However, as this storm system and approaching cold
front moves into Arkansas and the Ohio Valley Wednesday night, a
strong MCS will likely form over Arkansas and Kentucky and moves
southeast ahead of the front into the southern middle Tennessee
around midnight. This should continue to move southeast through
the overnight hours into the early morning hours on Thursday
morning. Expect this to be on a weakening trend (due to weakening
instability trends) as it moves into the area. However, some
severe thunderstorms still look possible around and shortly after
midnight. If this MCS accelerates southeast more than current
guidance suggests, then this severe window could be pushed back a
bit and start in the late evening hours. The main threats would be
large hail and damaging winds, but a tornado cannot be ruled out
especially if this MCS moves into the area before midnight.

Trailing stratiform precipitation in the wake of a rather broad
MCS early Thursday morning will likely be in progress across much
of the region at 12Z Thursday, but should slowly spread southeastward
over the course of the morning. Additional showers and perhaps a
few storms may also redevelop during the afternoon as a cold front
shifts southeastward through the TN Valley, but airmass recovery
in the wake of widespread early morning precip should not be
sufficient to raise concern for strong-severe convection.

&&

.LONG TERM...
(Thursday night through Monday)
Issued at 318 PM CDT Mon May 6 2024

A final round of postfrontal showers may occur late Thursday
night, along the northern fringe of another well organized
convective complex traveling eastward along the central Gulf
Coast. Beyond this point, a cooler/drier airmass in the wake of
the cold front will reduce POPs to around 10% on Friday and
Saturday. However, there are indications that another Gulf low may
develop late in the weekend, with a slight chance POP for showers
introduced on Sunday. Highs this weekend will be in the lower
70s, with lows in the l-m 50s.

&&

.AVIATION...
(06Z TAFS)
Issued at 1249 AM CDT Tue May 7 2024

VFR conditions are expected at KHSV and KMSL through the
overnight hours until MVFR CIGS slide in ~11Z. Southwesterly winds
will pick up towards 15Z and gust to 20-25 kts. Introduced a
PROB30 for thunderstorms Tuesday afternoon, otherwise VFR
conditions will prevail.

&&

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

&&

$$

NEAR TERM...JMS
SHORT TERM...KTW
LONG TERM...KTW
AVIATION...JMS