235
FXUS64 KHUN 170447
AFDHUN

Area Forecast Discussion
National Weather Service Huntsville AL
1147 PM CDT Thu May 16 2024

...New AVIATION...

.NEAR TERM...
(Rest of tonight)
Issued at 950 PM CDT Thu May 16 2024

A weak positively-tilted mid-level trough (extending from the
southern Great Plains southwestward into northern Mexico) will
remain nearly stationary overnight, with a belt of 30-40 knot WSW
flow aloft expected to persist downstream from this feature across
the TN Valley. A well-organized MCS (currently tracking across
southern LA) is predicted to travel eastward along the central
Gulf Coast in the vicinity of a surface trough/marine warm front
lying immediately inland from the coast, while additional showers
and thunderstorms in the vicinity of a weakening cold front and
preceding surface trough impact a broad region extending from
western AR northeastward into the Upper OH Valley.

The current expectation (based on radar data and recent near term
model guidance) is that light stratiform rain along the northern
edge of the Gulf Coast MCS will begin to spread northeastward into
the southwestern portion of the CWFA between 4-8Z, before
expanding further northeastward between 8-12Z. This has been
reflected in the updated weather grids, which indicate a high POP
for light rain but low QPF. Although lapse rates and CAPE aloft
will be sufficient for a few embedded thunderstorms, the overall
risk for convective precipitation appears rather low tonight.
Prior to the arrival of precipitation and thicker mid/high-level
clouds, some light fog will also be possible across northeast AL
as temps fall into the mid 60s.

&&

.SHORT TERM...
(Friday through Sunday)
Issued at 1243 PM CDT Thu May 16 2024

A high PoP, lighter QPF scenario seems to be more favored for our
portion of the TN valley Friday into Saturday. The wave over
TX will slowly eject east along a track further south along the
Gulf Coast this model run. This will focus more intense convection
Friday night into Saturday to our south, and significantly limit
much if any threat of organized strong to severe thunderstorms
for our area Friday or Saturday at this point. A rogue strong
storm or two can`t be ruled out with locally heavier rainfall. The
weaker extension of the larger trough position in the OH valley
will eventually shift southeast through our area late Saturday
into Sunday. Will stick fairly close to suggested blended
guidance, but the trend looks more and more like less impactful
thunderstorms and rainfall, at least this go around of the model
runs. After a cool down into the 70s Friday, temperatures should
warm back into the upper 70s to lower 80s Saturday, and lower to
middle 80s Sunday.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 402 AM CDT Thu May 16 2024

A system that is expected to bring unsettled weather to close out
this week, by Sunday should be moving eastward over the Mid
Atlantic. Most of the showers activity should be east of the
region in the morning. But heating of residual moisture and
resultant instability could bring isolated to scattered (20-30%)
chance of showers and thunderstorms. This convection should it
occur should remain east of the Interstate 65 corridor, and in the
afternoon. Otherwise despite weak cold air advection, high
temperatures to start the week should warm into the mid 80s.
Shower activity should end Sun evening as high pressure building
in from the west becomes more of an influence on the sensible
weather. Low temperatures should cool into the lower 60s. The
start of the workweek/Monday should feature mostly sunny skies,
with highs rising into the upper 80s. Similar if not a tad warmer
on Tuesday with highs warming to around 90 in few places. Lows
Mon/Tue night should range in the mid/upper 60s.

Surface high pressure should build east of the Tennessee Valley
during Mon/Tue, returning a southerly flow over the area. Another
system forming over the northern Great Plains will head towards
the Great Lakes. A cold front trailing the parent low over
southern Canada will move across the area on Wednesday. Thus have
returned shower and thunderstorm chances to the Valley, beginning
late Tue night and continuing on Wed. With clouds and rain
chances, high temperatures should be in the mid 80s.

&&

.AVIATION...
(06Z TAFS)
Issued at 1147 PM CDT Thu May 16 2024

There have been no significant changes to previous aviation
forecast reasoning, as lgt RA (and perhaps a couple of embedded
TSRA) along the northern periphery of a Gulf Coast MCS will begin
to spread northeastward into northern AL by 7-8Z. However, this
will occur with only minor reductions to vsby and cigs. In the
wake of the initial round of light precipitation (which should
progressively spread northeastward and out of the region btwn
14-18Z), additional storms may develop along a trailing outflow
boundary extending from northern LA into west central AL, but with
low confidence in impacts as far north as MSL/HSV, we will not
include this scenario in the current TAFs. A more likely scenario
is that widespread low stratus clouds will develop by late morning
and persist for the rest of the period, with occasional lgt SHRA
possible as well. Sfc winds (initially from the SE at speeds less
than 5 kts) will shift to SSE and strengthen to 5-10 kts prior to
sunrise.

&&

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

&&

$$

NEAR TERM...70/DD
SHORT TERM...17
LONG TERM...RSB
AVIATION...70/DD