390
FXUS64 KHUN 171136
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
636 AM CDT Fri May 17 2024

...New AVIATION...

.NEAR TERM...
(Today)
Issued at 255 AM CDT Fri May 17 2024

An area of low pressure continue to move ESE along a warm front
draped just south of the northern Gulf of Mexico. This feature
has brought very severe thunderstorm activity to southern Texas
and Louisiana/Mississippi very early this morning. However, the
strongest activity seems to be shifting more offshore into the
Gulf of Mexico over the last few hours.

Further north of the low pressure center, a large shield of light
to moderate rain with some embedded isolated elevated storms
continue to move northeast into the area. In most areas, surface
dewpoint depressions are less than 5 degrees. So the expect light
to moderate rain being produced by isentropic lift will overspread
northern Alabama and southern middle Tennessee over the next hour
or so. Based on area temperatures and dewpoints, lows will likely
be able to drop into the lower to mid 60s.

Most guidance keeps light to moderate rainfall and maybe a few
elevated thunderstorms in the forecast this morning, before most
of it moves northeast or southeast of the area by the early/mid
afternoon hours. This morning rainfall and lingering cloud cover
should keep highs noticeably cooler with highs only reaching the
lower to mid 70s in most locations (a few upper 60s possible in
higher elevations).

Most guidance moves an upper level low over NE Texas/eastern
Oklahoma ENE along a very slow moving front into central/northern
Arkansas late this afternoon into the early evening hours. This
should be the focusing mechanism for another round of showers and
thunderstorms over those areas mostly to our west.

&&

.SHORT TERM...
(Tonight through Monday)
Issued at 255 AM CDT Fri May 17 2024

Whether this area of showers and thunderstorms can maintain
itself or strengthen as the front moves into NW Alabama later this
evening is a big question mark. Shear is very weak (15 to 25
knots) in most guidance. CAPE is not overly impressive, but does
climb to between 500 and 1200 J/KG later today in guidance. Given
the weak shear and worked over atmosphere, despite the front
moving into NW Alabama and southern middle Tennessee, not
expecting precipitation coverage to be much.

However, during the day on Saturday, as the front moves further
southeast into the area, daytime heating should allow for an area
of showers and thunderstorms should reform along the front. Again
shear will be very weak. Instability won`t be overly impressive
either (mainly 500 to 1000 J/KG). Thus, not expecting any severe
thunderstorm activity. However an area of showers and thunderstorms
will likely develop. The weak cold front and upper level trough
axis associated with it move southeast into southern Alabama and
Georgia late Saturday night in all guidance. Returning sunshine
and some warm air advection should allow highs to climb back into
the upper 70s.

By Sunday morning, expect a dry forecast west of the I-65 corridor,
as an amplified upper ridge begins building east into the area.
Lows will be slightly cooler, but not alot with temperatures in
the 60 to 64 degree range as you wake up. However, with a weak
upper low just to our east of southeast along the front, a low
chance (20-30%) of showers cannot be ruled out. The very strong
upper level ridge working into the area combined with returning
sunshine should allow temperatures to climb into the lower to mid
80s.

This upper level ridging only become more amplified Sunday night
into Monday morning. An upper level disturbance moves well north
of the area on the NW side of the upper ridge towards the Ohio
Valley into Monday morning. The overall pattern doesn`t change
much though into Monday. Lows shouldn`t change much, but highs
will likely warm a bit more into the mid 80s in most locations on
Monday with dry weather firmly in place.

&&

.LONG TERM...
(Monday night through Thursday)
Issued at 255 AM CDT Fri May 17 2024

Dry and warm conditions will continue into Tuesday, and thanks to a
flow rounding a surface ridge along the east coast. After a mild
night with lows in the lower 60s, highs on Monday should rise into
the mid 80s under mostly sunny skies. This trend should continue on
Tuesday with highs nearing 90 degrees in a few places. Lows in the
mid 60s Mon night should range in the upper 60s to near 70 Tue night.

A storm system forecast to form over the Rockies and adjacent High
Plains over the weekend will head to the NE, reaching the Great
Lakes on Wednesday. A cold front trailing south of it will move
across the area on Wed. Moisture convergence and lift preceding it
will return medium chances (30-50%) of showers and thunderstorms
beginning Tue night. Unsettled weather with scattered showers and
thunderstorms will remain in the forecast into Thursday. Overall
storm strength should remain "general" with a risk of strong outflow
wind gusts, heavy downpours, and sudden and/or frequent lightning.
Even with more clouds and rain chances, high temperatures on Wed/Thu
should range in the mid/upper 80s, and lows in the 60s.

&&

.AVIATION...
(12Z TAFS)
Issued at 636 AM CDT Fri May 17 2024

VFR CIGS and VSBYS will likely continue for a good portion of he
morning. Expect VSBYS and CIGS to become MVFR around 17Z or 18Z a
the terminals. Included a tempo group for -SHRA impacting both
terminals between 17Z and 22Z and CIGS dropping to around 1000
feet. This may need to be pushed back an hour or two. Then expect
predominant MVFR CIGS. For now stayed more conservative with CIGS,
but they may need to be lowered after 21Z to below 1000 feet.

&&

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

$$

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