911
FXUS64 KHUN 050913
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
413 AM CDT Fri Jul 5 2024

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

.NEAR TERM...
(Today)
Issued at 413 AM CDT Fri Jul 5 2024

A flat subtropical ridge (centered over the Lower MS Valley
yesterday evening) will continue to weaken over the course of the
early morning hours in response to a northern stream shortwave
trough digging southeastward across southern MN. At the surface,
an area of low pressure related to the aforementioned trough will
shift slowly eastward across southern WI, with a trailing cold
front extending southwestward through the Mid-MS Valley and Red
River Valley region of OK/TX. We are currently monitoring the
progress of a large area of prefrontal convection to our NW (which
originated across southern MO/northern AR yesterday evening), but
present indications are that this activity will not reach our
CWFA prior to 12Z. Nevertheless, a few showers and thunderstorms
may develop through sunrise in the strengthening low-level warm
advection regime downstream from the MCS, and we have maintained a
20-30% POP to account for this possibility. Low temperatures will
be quite warm due to the high moisture content of the boundary
layer, and may only reach the u70s-l80s in many locations, with
haze and fog possible (especially in the wake of fireworks
yesterday evening).

Latest high-resolution model guidance suggests that the
southwestern edge of the MCS will likely spread southeastward
across our forecast area during the late morning hours, with our
highest POPs (80-90%) reserved for the 12-18Z timeframe. However,
depending on the quality of airmass recovery that can occur in the
wake of this system, additional thunderstorms may redevelop this
afternoon as the slow-moving cold front begins to enter the region
from the northwest. With mid-level southwesterly flow predicted
to strengthen into the 20-25 knot range as the northern stream
trough shifts into the western Great Lakes and the subtropical
ridge becomes more centered along the Atlantic coast of
GA/northern FL, a few strong storms will be possible given CAPE in
the 2000-2500 J/kg range. Finally, although the max temperature
forecast is a bit uncertain due to the anticipated coverage of
clouds and precipitation early in the day, it seems reasonable to
believe that most locations will at least briefly touch the lower
90s, which (coupled with dewpoints in the mid 70s) will achieve
Heat Advisory criteria once again, and we will maintain the NPW at
the present time.

&&

.SHORT TERM...
(Tonight through Sunday night)
Issued at 413 AM CDT Fri Jul 5 2024

Showers and thunderstorms will likely begin to diminish in
coverage and intensity around sunset this evening, but with the
cold front still to our northwest at 0Z, we will maintain a low-
medium POP for most of the region through late this evening
(highest in the southeast). Latest model consensus indicates that
the cold front will indeed clear our region early Saturday
morning, with only a low (15-20%) POP maintained for our
southeastern counties during the day to account for some
uncertainty regarding the precise location of the boundary.
Although dewpoints may fall into the l-m 60s in the postfrontal
airmass, highs should still manage to reach the lower 90s
Saturday, with lows falling into the u60s-l70s Sunday morning.
Present indications are that the front will begin to retreat
northward at some point Sunday afternoon/evening, ushering a
warmer and more humid airmass into the region once again, and we
have increased POPs both periods to account for this.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 413 AM CDT Fri Jul 5 2024

By Monday, we will be back in a warm sectored airmass with upper
ridging centered off the Atlantic Coast and an upper trough making
its way through the central Plains and into the Midwest. The
upper ridge over the Atlantic looks to remain dominant over a
large portion of the Southeast through at least the mid-week
period, as the upper trough becomes less amplified as it moves
across the Great Lakes and into Canada. This will keep near
seasonable temperatures (highs in the upper 80s/lower 90s) in
place with daily chances for rain and storms, peaking (40-60%)
during the afternoon diurnal heating hours. The track of the
eventual remnants of Hurricane Beryl is still pretty uncertain at
this time, and low confidence exists regarding whether or not the
Tennessee Valley will see any rain from this system or not. For
that reason, have stuck with blended guidance for PoPs given that
it is at the 6-7 day range which suggest a 30-50% PoP Wednesday
and Thursday. Overnight lows will be in the upper 60s to mid 70s
each night.

&&

.AVIATION...
(06Z TAFS)
Issued at 116 AM CDT Fri Jul 5 2024

VFR conditions will prevail through the early overnight hours
before showers and thunderstorms arrive over the area around
sunrise. Expect showers and thunderstorms to persist on and off
through much of the TAF period, with reductions to MVFR conditions
likely although confidence in timing remains low. Brief
reductions to IFR conditions will be possible during heavier
showers and thunderstorms, and gusty winds may also accompany the
heavier shower/storm activity.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...

AL...Heat Advisory until 7 PM CDT this evening for ALZ001>010-016.

TN...Heat Advisory until 7 PM CDT this evening for TNZ076-096-097.

&&

$$

NEAR TERM...70/DD
SHORT TERM...70/DD
LONG TERM...26
AVIATION...25