902
FXUS64 KHUN 151736
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1236 PM CDT Thu Aug 15 2024

...New AVIATION...

.NEAR TERM...
(Rest of Today)
Issued at 816 AM CDT Thu Aug 15 2024

High pressure to our SW will hold on for one more day yielding
another afternoon of hot and humid conditions. The high pressure
center will begin to deteriorate and retrograde as a low pressure
trough pushes through the Great Lakes region. Aloft, this will
introduce NW flow slowly throughout the day signaling a pattern
switch that will become more apparent through the first half of
the weekend (see short term forecast). At the surface, the only
impact for the remainder of today will be a low chances of showers
and thunderstorms on the NE periphery of lingering high pressure
in NE AL. Any showers that do develop will be diurnally driven
meaning they will likely be scattered in nature and dissipate with
the loss of daytime heating. The lingering high pressure will
also support heat indices from the 94-104 degree range. This is
just below advisory criteria but still warrants the same sun and
heat safety cautions for those partaking in outdoor activities.

&&

.SHORT TERM...
(Tonight through Saturday night)
Issued at 419 AM CDT Thu Aug 15 2024

Over the course of the short term period, the northern stream
trough and relate surface cyclone (discussed in the near term
section) will spread southeastward from the Upper MS Valley into
the Lower Great Lakes by Saturday afternoon/evening, with WSW flow
in the low-levels maintaining a warm and increasingly moist
airmass across the TN Valley, as we will remain south of the
trailing cold front (at least through Sunday morning). Latest
convection-allowing guidance suggests that clusters of
thunderstorms will develop very late this afternoon both in the
vicinity of a prefrontal confluence axis extending from southern
MO into OK, as well as further north (in the vicinity of Kansas
City). Although this activity may have a tendency to grow into a
broader southeastward-moving MCS early Friday morning, it may only
reach western and perhaps northern portions of Middle TN before
dissipating at the peak of the nocturnal cooling cycle.
Redevelopment of thunderstorms in the vicinity of a remnant
outflow boundary across our region early Friday afternoon appears
a more likely scenario at this point, and some of this activity
could be strong-marginally severe given the combination of mid-
level WNW flow of 15-25 knots, MLCAPE of 2000-2500 J/kg and steep
low-level lapse rates. Prior to the initiation of convection,
temps in the l-m 90s and dewpoints in the l-m 70s will yield
apparent temps of 100-105F.

Additional impacts from MCSs are anticipated on Friday night, but
genesis regions are unclear at this point as some global models
suggest redevelopment of storms across Middle TN, while others
indicate the formation of a broader cluster of storms across
eastern KS/western MO. Regardless of which scenario materializes,
storms will be tracking east-southeastward, and we will maintain a
medium-high (40-60%) POP through the evening hours. Conditions
will become more favorable for organized severe thunderstorms
during the day on Saturday, as WNW winds aloft strengthen to 30-40
knots along with even higher CAPE values during the afternoon.
Although confidence in timing and spatial extent of thunderstorm
coverage decreases considerably at this time range, we will
maintain a medium-high (50-60%) chance for storms during the
afternoon, with most models suggesting redevelopment of convection
along another remnant outflow boundary. A final band of showers
and thunderstorms may shift southward through the region early
Sunday morning in conjunction with the cold front, but convective
overturning by this point will reduce the risk for severe
winds/hail.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 419 AM CDT Thu Aug 15 2024

The upper trough centered just to our east will continue to dig
south through the second half of the weekend, and will lead to a
cooler, drier pattern to start the work week. Will keep low
chances (20-30%) for showers/storms Sunday with the cold front
expected to push south through the area Sunday afternoon/evening.
By then, expect the better strong/severe thunderstorm environment
to be to our south where the axis of better moisture lies. Dry
weather will return by late Sunday, and northerly flow will begin
to advect cooler temperatures into the area. The remainder of the
long term forecast looks very nice for mid to late August, with
daily highs in the 80s and lows in the low to mid 60s. High
pressure will help us maintain a dry forecast through Wednesday.

&&

.AVIATION...
(18Z TAFS)
Issued at 1236 PM CDT Thu Aug 15 2024

VFR conditions will prevail through the duration of the TAF
period. After sunrise tomorrow winds will shift from SE to SW with
a slight increase in winds speed to around 6 KTS. There is a low
chance of rain and storms from 12-18Z tomorrow however confidence
was too low to include in the TAF. In confidence increases rain
and thunder will be added to the TAF during additional issuances.

&&

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

$$

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