773
FXUS64 KHUN 202256
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
556 PM CDT Thu Jun 20 2024

...New AVIATION...

.NEAR TERM...
(Tonight)
Issued at 316 PM CDT Thu Jun 20 2024

A fairly widespread cumulus deck has kept temperatures a bit
cooler than expected so far today. Temperatures currently are in
the upper 80s to around 90 degrees. Models hint that this cumulus
field might lessen in coverage around 4 PM. This could allow highs
to still reach the 92 to 94 degree range in some locations.

This cumulus field should dissipate quickly after sunset, as a
large area of high pressure to our northeast continues to build
southwest into the area. This will allow for very light if not
calm winds to develop tonight. This should allow for good
radiational cooling conditions. Thus, went slightly below guidance
for lows tonight. Not going too far below guidance for lows given
a weak pre-frontal trough axis may be able to focus an axis of
higher low level moisture into the center of the ridge south into
the area near and west of the I-65 corridor. Some lows in the mid
to upper 60s seem reasonable near and east of the I-65 corridor.
Elsewhere, expect lows to drop only into the upper 60s to lower
70s. For now, fog was left out of the forecast overnight.

&&

.SHORT TERM...
(Friday through Sunday)
Issued at 316 PM CDT Thu Jun 20 2024

The big forecast feature will continue to the be the large area of
high pressure that settles southwest into the Tennessee Valley
through the weekend. A couple models to show some 700 mb and 300
mb higher relative humidity values, possibly associated with some
cloud cover near the pre-frontal trough axis mentioned earlier
that doesn`t move much. Otherwise, we would likely be looking at
more widespread upper 90s Friday through Sunday. Also, the ridge
itself will slowly weaken as the center of it shifts further
southeast through that period.

Having said that, widespread lower to mid 90s still look probable
with some upper 90s possible by Sunday. With dewpoints in the 65
to 70 degree range, heat index values will likely climb above 100
degrees, but just shy of 105 degrees. Still be aware and careful
if working outdoors and stay hydrated.

If this cloud cover does not pan out, then temperatures could be a
few degrees warmer than the current forecast. This would likely
push heat index values into Advisory criteria if this occurs.

&&

.LONG TERM...
(Sunday night through Thursday)
Issued at 316 PM CDT Thu Jun 20 2024

Latest extended range models indicate that this area of high
pressure continues to shift WSW and centered across AZ/NM at the
by Sunday night. Latest guidance shows precipitation ahead of an
approaching front staying north of the area until the evening
hours on Sunday. However, enough cloud cover may make it into the
area in the mid/late afternoon hours to produce enough cloud cover
to keep highs a bit lower than previously thought. Highs should
still make it into the 95 to 98 degree range in most locations.
Low chance PoP (20-30%) was kept in the forecast starting Sunday
evening as the front moves into the area. This front weakens and
slows down on Monday morning. Despite that kept a 20 PoP in the
forecast on Monday. Due to expected cloud cover expect highs to be
tempered slightly, but still should reach the lower to mid 90s.
With a more moisture boundary layer with the front still departing
the area, heat index values may reach 105 degrees in a few more
locations.

During the period from Tuesday-Wednesday, guidance suggests that
the frontal boundary will begin to lift northeastward in response
to another northern stream trough and related surface low moving
eastward across Ontario/Quebec. The introduction of light SW
flow/richer low-level moisture, coupled with less influence from
the subtropical ridge aloft, should allow for a greater coverage
of afternoon/evening showers and storms both days, along with
slightly cooler afternoon high temperatures.

&&

.AVIATION...
(00Z TAFS)
Issued at 556 PM CDT Thu Jun 20 2024

VFR conditions will prevail at both terminals for the duration of
the TAF period. The scattered lower cloud deck will erode as the
sun sets with clear skies and light and variable winds developing
overnight through the day tomorrow.

&&

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

$$

NEAR TERM...KTW
SHORT TERM....KTW
LONG TERM....KTW
AVIATION...RAD