-- Discussion containing changed information from previous version are highlighted. --
601
FXUS64 KHUN 161818
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
118 PM CDT Sun Jun 16 2024

...New NEAR TERM, SHORT TERM...

.NEAR TERM...
-- Changed Discussion --
(Tonight)
Issued at 118 PM CDT Sun Jun 16 2024

Another hot/humid day across the Tennessee Valley with early
afternoon temperatures in the low/mid 90s forecast to climb an
additional 2-3 degrees before the day is done. Dewpoints have held
in the lower 70s in most locations and subsequently heat indices
range from 97 to 104 degrees across the area as of 18z. With a
few more hours of good heating left, it`s possible heat indices
could exceed 105 degrees briefly in a few locations, especially in
the Huntsville-Muscle Shoals-Decatur metro areas. This heat will
be dangerous to vulnerable populations, and everyone is urged
exercise caution during the peak heating of the day.

A scattered Cu field early this afternoon will gradually give way
to a few showers and thunderstorms, mainly during the 21-01z
window when peak diurnal heating is realized. This activity will
be limited on coverage and intensity -- with gusty winds being the
main threat with strongest cells. Cloud cover and convection will
dissipate quickly with the loss of heating after sunset, with
mostly clear conditions forecast once again. Overnight lows in the
low to mid 70s will be common once again.
-- End Changed Discussion --

&&

.SHORT TERM...
-- Changed Discussion --
(Monday through Tuesday)
Issued at 118 PM CDT Sun Jun 16 2024

The center of the ridge will become more displaced to the north
and east of the area on Monday and subsequently temperatures may
run a couple degrees lower -- with highs peaking in the low to
mid 90s. However, with lower 70s dewpoints remaining in place,
peak heat indices in the 97 to 103 range will be common once
again. Thus, those most vulnerable to heat should take extra
precautions and avoid being outdoors during peak heating of the
day. Diurnally driven "pulse" convection will once again be
possible once again during the mid/late afternoon hours, before
dissipating with the setting sun.

The mid/upper ridge to the northeast will begin to build back
into the area, providing enough subsidence to suppress convection
for Tuesday. Mostly sunny and dry conditions will prevail with
highs running a just a tad lower in the lower 90s in most
locations.
-- End Changed Discussion --

&&

.LONG TERM...
(Tuesday night through Saturday)
Issued at 232 AM CDT Sun Jun 16 2024

Summer-like warmth will continue over much of the southeast and
eastern Lower-48, as strong upper level ridging becomes a controlling
feature for our sensible weather. This upper ridge should be centered
over the coastal Mid Atlantic and New England with maximum heights
around 597 decameters. The ridge will strengthen even more as we go
through second half of the week, peaking at 600 decameters from
Wednesday into late Thursday. The presence of the ridge although
located more to our NE, should be close enough to suppress convection,
due to warm temperatures aloft and subsidence that occurs under
strong areas of high pressure.

Juneteenth/Wednesday should feature more clouds than sun with highs
rising to around 90, which is close to seasonable norms. Overall
atmospheric moisture over this region should decrease Wed night, with
lows around 70. Thursday, and the first day of Summer (which occurs
around 351 PM CDT) should come in style with highs rising into
the low/mid 90s. A tad warmer is expected on Friday with highs in
the mid 90s. Corresponding heat index values on Juneteenth should
range close to the air temperatures in the Wed-Fri timeframe. Low
temps in this period should cool into the upper 60s to lower 70s.

A system of tropical origins could move over the SE coast (north
Florida to South Carolina) in the Thu/Fri timeframe. Output from
the various model camps are uncertain with timing and strength
with this feature. The GFS was the fastest and further south
solution with it coming ashore Thu, while the ECMWF was more over
the GA/SC coast Thu night, and the Canadian over the SC coast Fri
and the weakest depiction. In any case, moisture from the tropics
will move across the Tennessee Valley late Friday into Saturday.
Strong daytime heating Sat with highs in the mid 90s and heat
index values to 101 will produce a more unstable environment.
There appears to be enough moisture to help a few showers and
thunderstorms form Sat afternoon over the entire area.

&&

.AVIATION...
(18Z TAFS)
Issued at 1146 AM CDT Sun Jun 16 2024

VFR conditions will be the predominant flight category at both
terminals through the period. Low chances (20-30%) for SHRA/TSRA
are forecast this afternoon between 21-01z. Should a rogue storm
impact either terminal, amendments and AWWs will be needed. Storms
will dissipate shortly after sunset, with VFR conditions
prevailing through the remainder of the period.

&&

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

$$

NEAR TERM...AMP.24
SHORT TERM....AMP.24
LONG TERM....RSB
AVIATION...AMP