696
FXUS64 KHUN 151744
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1244 PM CDT Mon Jul 15 2024

...New AVIATION...

.NEAR TERM...
(Rest of Today)
Issued at 1004 AM CDT Mon Jul 15 2024

Temps as of 15Z are in the mid 80s to the lower 80s where there
is greater cloud cover and a few light showers. We will remain in
the NW periphery of a subtropical high today, but with an
approaching shortwave that will round the trough, expecting to see
low to medium chances (20-50%) of shower and thunderstorms by
this afternoon. The greatest coverage will be east of a line
stretching from Cullman Co up to Franklin Co TN. With the high
PWATS and given instability up to 2k J/kg, a few storms could be
strong producing gusty winds. With the slow steering flow, storms
will be slow moving and also produce heavy downpours.

On the flip side, heat will also be a factor yet again today. Will
be closely monitoring cloud cover and T/Td trends as we are on the
cusp of a Heat Advisory. Regardless, heat safety needs to be taken
seriously. Take breaks, stay hydrated, and never leave people or
pets in a unattended vehicle.

&&

.SHORT TERM...
(Tonight through Wednesday night)
Issued at 453 AM CDT Mon Jul 15 2024

Afternoon shower and thunderstorm activity will begin to diminish
in both coverage and intensity around sunset this evening, but
with some large scale ascent still being provided by the shortwave
disturbance (noted above), convection may not dissipate as
quickly as in previous nights. Thus, we will leave a low- medium
POP in the grids this evening, ranging from 20% (NW) to 40% (SE).
Patchy fog may develop in a few areas late this evening
(especially those locations that experience rainfall), with a
warm/muggy night in store featuring lows in the l-m 70s. Little
change in the weather pattern is anticipated on Tuesday, although
the departure of the shortwave trough to the east may result in
weak subsidence and drying aloft, which could limit the coverage
of afternoon showers/storms and result in temps a degree or two
higher than Monday. If this trend continues, then a Heat Advisory
may be warranted for portions of the local CWFA.

It still appears as if the synoptic pattern across our region
will begin to change on Tuesday night, as a northern stream
shortwave trough digging into the Upper MS Valley will induce an
increase in SW flow aloft. Although the slow-moving cold front
related to this trough will remain well to the north of the region
(in the OH Valley), strengthening deep-layer southwesterly flow
may foster the development of nocturnal thunderstorms over
portions of the TN Valley (especially during the early morning
hours on Wednesday). Latest model solutions indicate that the
slow-moving cold front will drift southward into the I-40 corridor
of TN by Wednesday afternoon, with the greatest concentration of
convection throughout the day likely to remain to our north.
However, there is some concern that a prefrontal trough may
initiate showers and storms in our region by late Wednesday
morning, and we have maintained suggested POPs of 55-65% during
the afternoon hours. Due to the potential for morning clouds and
early development of convection, highs should only reach the
u80s-l90s, reducing the overall Heat Risk. A fairly widespread
coverage of showers and thunderstorms will continue on Wednesday
evening as the cold front makes its way southward into our region.

&&

.LONG TERM...
(Thursday through Sunday)
Issued at 453 AM CDT Mon Jul 15 2024

Extended range guidance from the global models still suggests
that a slightly cooler and wetter weather pattern is in store for
the local area beginning later this week and extending into the
weekend. This will take shape as a mid/upper-level longwave trough
axis becomes established to the west of the local area, inducing
modest (20-30 knot) SW flow atop a stalled frontal boundary that
may reside across the CWFA for much of the period. With the
potential for several smaller scale disturbances to track across
the region in the SW flow aloft and PWAT values predicted to be
near or slightly in excess of 2", several rounds of showers and
storms will occur both during the day and at night. Locally heavy
rainfall may eventually become a concern (especially across the
southeastern portion of the forecast area, where the impacts of
drier continental air will not be felt). Fortunately, the
combination of clouds and precipitation will yield cooler
temperatures in the m-u 80s (afternoon) and u60s-l70s (overnight).

&&

.AVIATION...
(18Z TAFS)
Issued at 1244 PM CDT Mon Jul 15 2024

Prevailing VFR conditions expected at both KMSL and KHSV through
the TAF period. However, pop-up storms are currently beginning to
fire up near the sites. If any of these go over the terminals,
brief MVFR (vis and sigs) conditions would occur. Given the
nature of these pulse-like storms, there is uncertainty on
whether or not these storms will go over the airports, which is
why VCTS prevails through about 00-01z time frame.

&&

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

$$

NEAR TERM...JMS
SHORT TERM....70
LONG TERM....70
AVIATION...Serre