Flash Flood Warning 17, NWS Nashville, TN

Area Forecast Discussion
National Weather Service Nashville TN
613 PM CDT Thu Jul 16 2026

...New UPDATE, AVIATION...

.KEY MESSAGES...
Updated at 603 PM CDT Thu Jul 16 2026

- Daily rounds of storms will continue through the weekend. Strong
  winds gusts and heavy rain causing localized flooding are possible
  in stronger storms.

- Temperatures will warm with heat indices in the low-100s west
  of the Plateau Friday into early next week.

- Tuesday will be the hottest day of the period with heat indices
  nearing or exceeding 105 degrees for most of the area.

&&

.UPDATE...
Issued at 603 PM CDT Thu Jul 16 2026

Another day, another crop of showers and thunderstorms. Isolated
showers are still ongoing at this hour, but today's activity
hasn't been that impressive with only a little lightning produced.
This activity will wane once the sun sets, giving us a mainly
quiet night. Fog will once again be a concern though, particularly
for areas that have received rain today. Look for additional
showers & storms to develop by tomorrow afternoon with the typical
summertime hazards of lightning and brief heavy rain.

&&

.SHORT TERM...
(Rest of today through Friday)
Issued at 1108 AM CDT Thu Jul 16 2026

Largely a persistence forecast is underway for Middle Tennessee.
Weak synoptic forcing coupled with high moisture content (PWATs
around 2 inches, above the 90th percentile for mid July) has
sparked typical summertime convection. These are very slow-moving
showers and storms due to the weak steering flow, so localized
flooding will be a risk with any heavy downpours. Temperatures
will hold steady near normal today, but be on the lookout for a
warmer pattern change starting Friday. As a 594 dam midlevel ridge
starts to encroach on the southeastern CONUS Friday afternoon,
temperatures begin their slow climb.

&&

.LONG TERM...
(Friday Night through next Thursday)
Issued at 1108 AM CDT Thu Jul 16 2026

We should stay below Heat Advisory criteria (heat index of 105F+)
through the weekend, but will start seeing more frequent heat
indices in the triple digits. PoPs are also on the rise this
weekend as a result of a few shortwave systems embedded in the
main flow. A more noteworthy feature is forecast to sweep through
Saturday evening, bringing a wave of showers and perhaps a few
stronger thunderstorms through Middle Tennessee. Initial look at
the parameter space indicates a very weakly sheared environment,
suggesting our primary threat will be damaging winds on the
storms' outflows. Lapse rates look quite poor (around 5 degC/km),
mitigating the hail threat. Much of the area will see some type
of precipitation as this feature moves through late Saturday
night, but the bulk of the severe weather threat will be confined
to areas along and east of I-24.

The hottest day of the forecast period certainly looks to be
Tuesday; midlevel ridging combined with an approaching frontal
boundary at the surface will most likely cause muggy air to pool
along the south side of the front on Tuesday afternoon. This will
lead to dangerous heat and humidity sending heat indices at or
above 105 degrees on Tuesday, so we will be monitoring the need
for heat headlines. After this front passes, temperatures finally
return to near normal in the upper 80s for the remainder of the
week.

&&

.AVIATION...
(00Z TAFS)
Issued at 603 PM CDT Thu Jul 16 2026

Isolated showers & storms will diminish around 01Z. Light
southwest winds will continue overnight with patchy fog
developing, resulting in MVFR to IFR conditions. Highest
confidence in fog impacts are at SRB and CSV. Any fog that does
develop will diminish between 12Z and 14Z. Another round of
isolated to scattered showers & storms will develop by early
Friday afternoon and introduced PROB30 groups for each terminal.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      74  90  74  91 /  10  60  20  50
Clarksville    73  89  74  91 /  20  50  10  40
Crossville     70  85  69  84 /  20  60  20  80
Columbia       72  90  72  91 /  10  60  20  50
Cookeville     72  86  71  86 /  20  50  40  80
Jamestown      71  86  70  85 /  20  60  30  80
Lawrenceburg   71  88  71  89 /  10  70  20  60
Murfreesboro   73  90  73  91 /  10  70  30  70
Waverly        72  89  73  90 /  10  50  10  30

&&

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

UPDATE.......Clements
SHORT TERM...Dirkes
LONG TERM....Dirkes
AVIATION.....Clements