550
FXUS64 KHUN 201041
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
541 AM CDT Sun Jul 20 2025

...New AVIATION...

.NEAR TERM...
(Today)
Issued at 300 AM CDT Sun Jul 20 2025

High pressure will maintain its dominance over the TN Valley and
southeastern CONUS through the day today. The resulting SE flow
will continue to plague the area with high tropical dew points
from the Gulf in the mid to high 70s. The building high pressure
will allow temps to increase to the high 80s and low 90s this
afternoon and limit rain and storm chances to below 30%. While
the temps alone are manageable for a July day, the temps paired
with tropical dew points will push apparent temperatures into 100s
for most of the area.

The big forecast challenge today will be just how high apparent
temperatures get. Confidence remains high in seeing dewpoints in
the 75-77 range as the tropical airmass has produced these the
last few days. Uncertainty remains in what our exact high
temperatures will be today. HREF models continue to support cloud
cover developing over NW AL through the afternoon. This would
limit high temperatures to the low 90s and keep apparent
temperatures below Heat Advisory criteria. With this solution
being shown in several models, we have held off on issuing a Heat
Advisory today. Should cloud cover be more scarce than forecast,
we may over preform slightly in high temperatures and push
apparent temperatures, especially in urban area, near and just
above 105. Regardless of reaching criteria or not this afternoon,
hot and humid conditions will pose the same risk to those
spending time outside. Please make sure to practice proper heat
safety.

&&

.SHORT TERM...
(Sunday night through Tuesday night)
Issued at 956 PM CDT Sat Jul 19 2025

High pressure will continue to amplify over the Southeast during
the first half of the week and the threat for dangerous heat will
continue through at least Tuesday. Afternoon heat indices will
rise into the 105-110 degree range both Monday and Tuesday, and
Heat Advisories will likely be needed across portions of the
forecast area in future updates. Low to medium chances (30-50%)
for rain and thunderstorms will continue through this period as
well, with a few strong to marginally severe thunderstorms
possible on Monday when moisture and instability appear to be
strongest. The primary threat with any stronger storms will be
downburst winds and torrential rainfall. With recent heavy
rainfall and wet soil, some trees may be more susceptible to
falling within stronger wind gusts. In addition, flooding may
develop quicker due to the saturated soils and a very moist
airmass (PWATs between 2-2.2") so be sure to pay extra attention
if driving through heavy rain.

&&

.LONG TERM...
(Wednesday through Saturday)
Issued at 956 PM CDT Sat Jul 19 2025

In the extended portion of the forecast period, global models
suggest that an easterly wave will undercut a strong mid-level high
(initially centered across the Lower OH Valley). As the wave
progresses westward across the Gulf from Wednesday-Saturday, it will
effectively create a break in the subtropical ridge extending from
the central Gulf Coast northward into the central Appalachians/OH
Valley by the end of the period. In the low-levels, our region will
remain in a light-moderate SE flow regime between a high to our east
and a weak area of surface low pressure that will evolve within the
base of the easterly wave and retrograde westward across the northern
Gulf (perhaps in close proximity to the coastline).

Prior to the development of the weakness in the mid-level
subtropical ridge, coverage of showers/thunderstorms from the late
morning-early evening hours will be quite limited on
Wednesday/Thursday and perhaps into Friday as well, with the greater
spatial concentration of convection expected to occur within a plume
of deeper tropical moisture to our southeast. However, by Saturday,
the axis of deeper moisture will likely have spread northwestward
into our region, promoting an increase in shower/thunderstorm
activity (especially for the southeastern half of the CWFA).

Regarding temperatures and heat index values, it appears as if
Wednesday will mark the last day of overlap between afternoon temps
in the l-m 90s and dewpoints in the l-m 70s, as drier low-level air
will be advected into the region from the northeast (lowering heat
risk on Thursday/Friday in spite of highs remaining in the l-m 90s).
Beyond Friday, boundary layer dewpoints will begin to increase once
again, but with an increasing coverage of showers/storms expected as
well, the risk from excessive heat is more uncertain heading into
next weekend.

&&

.AVIATION...
(12Z TAFS)
Issued at 541 AM CDT Sun Jul 20 2025

VFR conditions will be the prevailing flight category through the
TAF period. There is a low chance of isolated storms this
afternoon. Due to low confidence, thunder was excluded from the
TAFS. That being said, should an isolated storm move directly over
the terminals, ceilings and visibilities may be briefly lowered.
Future TAF issuances will address this if confidence increases in
this possibility.


&&

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

$$

NEAR TERM...RAD
SHORT TERM....25
LONG TERM....70
AVIATION...RAD