620
FXUS64 KHUN 131712
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1212 PM CDT Tue Aug 13 2024

...New AVIATION...

.NEAR TERM...
(Rest of Today)
Issued at 830 AM CDT Tue Aug 13 2024

Mostly sunny and very warm conditions are forecast again today as
we remain under the influence of the upper high pressure axis
that is centered over the ArkLaTex. Our mean flow aloft will
continue to remain out of the WNW/NW which will reinforce the
drier air at the mid-levels. This is seen in model soundings that
are quite dry and indicate a stout capping inversion between
800-700 mb that will be very tough to break. Thus, our prospects
for convection remain extremely low, with no available CAPE for
storms. Other than a few to scattered decks Cu in the afternoon,
mostly sunny conditions will allow temperatures to rise into the
lower 90s -- with a few mid 90s possible across northern Alabama.
A MCS well to our west in KS/MO that will be decaying this
morning could provide some additional cirrus late in the day, but
think any hindrance to heating for this will be minimal. Dewpoints
will be a hare higher today, but slightly warmer temperatures
will also knock our RH values into the 40-45 percent range again.
Definitely warmer, but certainly not the worst that mid-August can
offer as far as heat/humidity impacts are concerned.

&&

.SHORT TERM...
(Tonight through Thursday night)
Issued at 142 AM CDT Tue Aug 13 2024

The aforementioned ridge will continue pushing east through the
remainder of the work week, and will result in increasing heat,
moisture, and rain chances. As dewpoints climb back into the 70s
toward mid-week, overnight lows will return to the warm side, only
falling to the low to mid 70s. Humidity will climb through
Thursday, resulting in low chances (10-20%) for
showers/thunderstorms during peak heating hours mainly west of
I-65 on Wednesday then over the entire area on Thursday as the
upper ridge centers over the lower MS River Valley and into the TN
Valley. Afternoon highs will be in the upper 80s/lower 90s with
heat indices near or just above 100 degrees on Thursday. This
places much of the area in a moderate HeatRisk, signaling caution
to those that are sensitive to heat or without proper cooling
means. Will have to monitor trends in the eastward progression of
the trough in case the chances of exceeding Heat Advisory criteria
of 105 degrees looks more probable. For now, just something to be
aware of as we head toward the later half of the week.

&&

.LONG TERM...
(Friday through Monday)
Issued at 142 AM CDT Tue Aug 13 2024

An upper shortwave trough is slated to progress from the Midwest
down into the Ohio and Tennessee valleys from Friday through early
Sunday morning. At the surface, a cold front looks to approach the
region from the northwest on Friday, then traverse the area sometime
Saturday evening or overnight. High pressure is then shown to build
into the Tennessee Valley early next week. This pattern will lead to
medium (40-50%) chances of showers and storms on Friday, with low to
medium (30-40%) chances on Saturday. Sufficient bulk shear and
instability may lead to at least some stronger storms ahead of the
front on Friday. Additionally, bulk shear values increase Saturday
afternoon and evening. Overall, confidence on severe weather for
Friday and/or Saturday is low at this time, but we`ll keep an eye on
these trends with subsequent updates. Low chances of lingering
showers and storms then comprise Sunday, with drier weather returning
early next week.

Temperatures will be warm to start, but will overall follow a
downward trend through the long term. Highs in the lower to mid 90s
are anticipated Friday and Saturday, with lows in the upper 60s to
lower 70s Friday night. The hottest day of the long term forecast
looks to be Friday, with heat indices potentially reaching Heat
Advisory criteria over portions of far northwestern Alabama. Most
of our local area is highlighted in a moderate risk of heat-
related illness from the NWS HeatRisk tool, with some spots over
northwest and north- central Alabama in a major risk. Will
continue to monitor in case a Heat Advisory becomes necessary;
but, in the meantime, please remember heat safety. Stay hydrated,
wear light-colored, loose- fitting clothes, and take frequent
breaks in the shade. Temperatures then begin to decrease a bit
after cold FROPA Saturday evening/night. Highs in the upper 80s to
lower 90s are expected Sunday and Monday, with lows in the mid to
upper 60s for most locations by Monday night. It`ll also be less
muggy by Monday, with dew points dropping into the 60s (versus dew
points in the lower 70s like on Friday).

&&

.AVIATION...
(18Z TAFS)
Issued at 1212 PM CDT Tue Aug 13 2024

VFR conditions will prevail through the period at both terminals,
with light winds. Scattered Cu will dissipate after sunset
resulting in a mostly clear sky. Late in the period, on Wednesday
morning, clouds will increase as the remnants of an MCS over the
Plains attempt to work its way into the area. Confidence was too
low to add a mention of SHRA/TSRA just yet, but we will continue
to watch this trend over the course of the evening hours

&&

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

$$

NEAR TERM...AMP
SHORT TERM....25
LONG TERM....26
AVIATION...AMP.24