199
FXUS64 KOHX 251128
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
628 AM CDT Wed Sep 25 2024

...New AVIATION...

.SHORT TERM...
(Today through Tonight)
Issued at 107 AM CDT Wed Sep 25 2024

A cold front has pushed eastward through Middle TN with latest obs
showing it just east of the Plateau. This front is expected to stall
in this area today as an upper-level low digs into northern AR.
In the wake of this front, temperatures will be cooler with
forecast highs in the 70s to near 80. While PWATs have trended
down over the past 24 hours, there is still plenty of moisture
across the area with PWATs over an inch. This will lead to an
additional round of showers and thunderstorms that develops this
morning and lingers through tonight. With the position of the
front, best coverage will favor the east today. In the wake of the
cold front and with cloudy skies, instability will be less with
CAPE values forecast to be less than 1000 J/kg. With less
instability and less forcing, strong to severe thunderstorms are
not expected today. Cloud cover partially clears tonight, allowing
for patchy fog to develop.

&&

.LONG TERM...
(Thursday through next Wednesday)
Issued at 107 AM CDT Wed Sep 25 2024

Confidence continues to increase for soaking rainfall starting
Thursday and continuing into the weekend. The aforementioned
upper-level low that digs into northern AR today will stall and
linger in this area into the weekend. Meanwhile, all eyes continue
to be on the tropics with now Tropical Storm Helene. Helene is
expected to strengthen into a major hurricane before making
landfall along the Florida Panhandle late Thursday. Before
Helene`s landfall, tropical moisture will be pulled northward with
the help of that low over AR. The heaviest rainfall expected from
Helene will likely get started Thursday night and continue into
Friday as its remnants then track into eastern TN. What`s left of
Helene at this point gets pulled northwestward across Middle TN/KY
and is absorbed into the AR upper-level low. This low then finally
ejects towards the northeast this weekend.

Heaviest rainfall during this event is expected Thursday night and
into Friday. A general 2 to 3 inches of rain is expected over this
time frame, but higher amounts of 4 to 5 inches will favor areas
across the Plateau. This is all highly dependent on the track of
Helene, and a jog towards the east will result in lower rain
amounts. Minor flooding is still possible with all this rain, but
with the current drought status, river levels are low enough that
there is room for this welcome rain. Winds will also be gusty,
especially on Friday as the remnants move through with gusts of 30
to 35 mph currently forecast.

Scattered showers and thunderstorms will linger through the weekend
before the low finally moves out of our area. Drier weather looks to
be favored early next week with temperatures feeling fall-like as we
head into the first week of October.

&&

.AVIATION...
(12Z TAFS)
Issued at 612 AM CDT Wed Sep 25 2024

There are some patches of low clouds that will affect BNA/MQY thru
14Z. Also, an area of mainly light rain is moving northeastward
out of West Tennessee that may affect CKV during the same time
frame. Drier air has worked its way into Middle Tennessee, so our
rain chances and expected rainfall amounts are considerably lower
today. The best rain chances will affect the Cumberland Plateau.
Ceilings and vsby`s will be somewhat variable today at CSV/SRB,
but look for low stratus and perhaps some fog to develop this
evening and especially overnight.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      80  63  77  67 /  50  30  70  90
Clarksville    78  59  78  66 /  20  20  70  80
Crossville     71  57  69  60 /  80  60  90  90
Columbia       79  59  76  64 /  40  30  70  80
Cookeville     73  60  71  63 /  70  50  70  90
Jamestown      73  59  70  62 /  70  60  80  90
Lawrenceburg   78  59  75  63 /  50  30  70  90
Murfreesboro   78  61  76  65 /  60  40  70  90
Waverly        78  58  77  63 /  20  20  60  80

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...Clements
LONG TERM....Clements
AVIATION.....Rose