984
FXUS64 KOHX 171738
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
1238 PM CDT Thu Jul 17 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 1226 PM CDT Thu Jul 17 2025

- A Heat Advisory is in effect for this afternoon as Heat Index
  values are expected to climb over 105F in several locations west
  of the Cumberland Plateau.

- Diurnal showers and thunderstorms will continue for the
  foreseeable future.

- The risk of severe weather is low, however, heavy rainfall,
  gusty winds, and frequent lightning will be possible with any
  storm.

&&

.SHORT TERM...
(Rest of today through Tonight)
Issued at 1114 AM CDT Thu Jul 17 2025

Hot. Muggy. Dare I say, disgusting? Meh. For me anyway. At 10 am,
BNA it was 87 with mid 70s dew points. If we use the 10 at 10
method we`re on our way to solidly verifying this Heat Advisory
today. It runs until 7 pm. This really should be the main story of
the day. I`m looking over these rain chances today and if you go
off the CAMs, the heat really is the only story as they depict the
bulk of rain chances remaining off to the north in Kentucky.
However, looking at surface obs across the area and visible
satellite, there`s an evident boundary laying across the mid-state
just north of I-40. In fact, we`re already starting to see some
showers bloom on the northern Plateau along this boundary. Without
much model guidance suggesting convective development in this
vicinity this afternoon, I don`t have much to go off of. WPC does
have our northern tier of counties highlighted for excessive
rainfall as part of a larger swath of a Slight Risk off to our
north. I have to imagine the thinking is outflows coming off
storms to our north and sparking convection along and north of
I-40 and this seems to be the most logical conclusion as the
energy associated with this upper trough remain off to our north.
With the lack of confidence in where storms will initiate this
afternoon, I`m not inclined to do anything widespread like a Flash
Flood Watch, however, interests north of I-40 will want to
closely monitor any storms this afternoon. PWs of close to 2
inches (1.9" from the 12Z OHX sounding) could support rain rates
up to 3 inches/hour. That said, the effects of storms like this
should be very localized and it`s a really long-winded way of
saying there`s a low to medium chance of diurnal storms (best
chance north of I-40) with heavy rain, lightning and gusty winds
today.

&&

.LONG TERM...
(Friday through next Thursday)
Issued at 1114 AM CDT Thu Jul 17 2025

As we move into tomorrow and the upcoming weekend, the story doesn`t
change much. Diurnal showers and storms will plague the forecast.
Afternoon highs shouldn`t be *quite* as warm, which should drop
us out of Heat Advisory territory, but Heat Index values should
remain 100-105F west of the Plateau each day.

Extended guidance keeps low to medium daily rain chances in the
forecast, however as we roll into the middle of next week, signals
for afternoon highs climbing into the mid to upper 90s persist.
This is due to an upper ridge exerting itself over the mid-south.
Storm coverage probably won`t be quite as high, if this ends up
verifying, but isolated storms can`t be ruled out with the typical
summertime concerns of gusty winds, lightning and copious
rainfall.

&&

.AVIATION...
(18Z TAFS)
Issued at 1226 PM CDT Thu Jul 17 2025

Visible satellite shows numerous cumulus clouds have blossomed
across the area over the last hour. High-res models are struggling
with where TS activity will develop this afternoon, thus PROB30
groups have been included at each site through 00Z. Should a storm
impact a terminal, expect a temporary reduction in vis due to very
heavy rain. VFR conditions will prevail outside of storms with
southerly winds near 5 kts. Fog chances are pretty low tonight,
however, those who receive rain today will have a better chance
of patchy fog development.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      76  92  75  92 /  30  50  40  60
Clarksville    75  90  75  90 /  40  60  40  50
Crossville     69  86  69  84 /  40  60  30  70
Columbia       74  91  73  90 /  20  50  40  60
Cookeville     72  87  72  85 /  40  60  40  70
Jamestown      71  86  70  84 /  40  70  40  80
Lawrenceburg   73  90  73  89 /  20  60  40  60
Murfreesboro   74  91  73  91 /  30  50  50  60
Waverly        74  90  73  89 /  40  40  40  50

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM CDT this evening for TNZ005>009-023>030-
056>062-075-093>095.

&&

$$

SHORT TERM...Unger
LONG TERM....Unger
AVIATION.....Baggett