-- Discussion containing changed information from previous version are highlighted. --
786
FXUS64 KHUN 191824
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
124 PM CDT Wed Jun 19 2024

...New AVIATION...

.NEAR TERM...
(Rest of Today)
Issued at 902 AM CDT Wed Jun 19 2024

A large area of high pressure continues to be centered off the
northeastern seaboard this morning. The western portion of this
ridge extends west into the southeastern CONUS.

Two boundaries extend southward from a parent low to a storm
system moving through southeastern Canada. One is an actual cold
front that extends from Wisconsin into central Iowa and western
Oklahoma. A weaker boundary is a weak area of convergence
extending from Michigan through Indiana and into eastern
Arkansas.

The strong area of high pressure is forecast in most models to
build to the WSW today and towards the Tennessee Valley. This will
push the forcing with these features further to the west a bit
today. This forcing is mainly producing mid/high cloud cover, but
it is thick enough to help dampen the heating today. Do expect
some clearing though in our southeastern counties such as Cullman,
Marshall, and DeKalb counties later this morning into the
afternoon hours. Further west near the AL/MS border, this cloud
cover may stay in place or increase some today. Some warm air
advection is shown in models today, so that might help push highs
everywhere into the 87 to 90 range. However, think some lower 90s
could occur in locations that see more sunshine, especially in
our southeastern counties.

&&

.SHORT TERM...
(Tonight through Friday night)
Issued at 355 AM CDT Wed Jun 19 2024

Low temperatures tonight should cool to around 70 as the upper
cloud deck slowly thins. With less cloud cover and the upper
high heading southward, higher heights/thicknesses and a strong
sun should return very warm to hot conditions on Thursday, highs
rising into the lower 90s. Thu is also the first day of summer
(which starts around 351 PM CDT). Similarly mild conditions Thu
night with lows around 70. Friday, the first full day of summer
will feel like summer, with highs warming into the low/mid 90s.
Corresponding heat index readings should range in the 90s both
Thu/Fri. And with high pressure controlling the weather, no
precipitation is expected into early Saturday.

&&

.LONG TERM...
(Saturday through Tuesday)
Issued at 355 AM CDT Wed Jun 19 2024

Guidance from the 0Z suite of global models suggests that a strong
mid-level high will be centered across the TN Valley at the beginning
of the extended forecast period. However, the subtropical ridge is
predicted to retrograde with time this weekend (becoming centered
across eastern NM/western TX by 0Z Monday) as a northern stream
trough digs east-southeastward along the U.S-Canadian border and into
the eastern Great Lakes. Although this evolution will result in a
gradual increase in NW flow aloft for the TN Valley, highs will still
manage to reach the m-u 90s in the valley on both Saturday and
Sunday (u80s in elevated terrain), with heat indices in the 98-102F
range as dewpoints creep back up into the u60s-l70s. Due to less of
an impact from subsidence, a few afternoon/evening showers and
thunderstorms will also return to the southeastern portion of the
CWFA Saturday, with a slight increase in spatial coverage for all
areas on Sunday.

There is reasonably good agreement among the models that a weak cold
front (attached to the northern stream trough) will drop southward
through the region on Monday, and we have indicated our highest POPs
for the extended period on this day. Frontal convection will likely
end south of the TN River Monday evening, with the front expected to
decelerate and become increasingly oriented in a NW-SE fashion to the
west of the forecast area on Monday night/Tuesday. Although a
slightly drier airmass may spread into the northeastern portion of
the region, there is some uncertainty regarding precisely where the
front will lie, and we have kept a low (~20% POP) intact for Tuesday.
High temperatures will change little (if at all) in the wake of the
front, but may be a couple of degrees cooler due to an increase in
cloudiness both days.

&&

.AVIATION...
-- Changed Discussion --
(18Z TAFS)
Issued at 122 PM CDT Wed Jun 19 2024

VFR conditions are expected throughout the TAF period with on and
off mainly high cloud cover over the next 24 hours. Wind gusts
from the east will drop off this evening, but remain around 5
knots much of the night. This should keep fog at bay.
-- End Changed Discussion --

&&

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

$$

NEAR TERM...KTW
SHORT TERM....RSB
LONG TERM....70
AVIATION...KTW