890
FXUS64 KOHX 201730
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
1230 PM CDT Sat Jul 20 2024

...New AVIATION...

.SHORT TERM...
(Rest of today through Sunday)
Issued at 1139 AM CDT Sat Jul 20 2024

Dew point temperatures are already in the low 70s for most around
the area this morning with air temperatures not too far ahead
with values in the upper 70s..Meaning our relative humidity values
are rising. Current surface map shows the frontal boundary draped
from the Carolinas all the way down to Texas with very slow
northern movement. With that, showers have developed along the
Alabama/Tennessee state border ahead of the boundary and continue
to drift north/northeast. Do expect more widespread coverage
across the Cumberland Plateau later this afternoon as that
boundary treks into the area. For the remainder of middle
Tennessee, the latest 12Z HREF solution shows scattered coverage
filling in across the majority of the area this afternoon as
daytime heating ramps up instability values. On the plus side, the
threat for severe weather is very low. Mid-level lapse rates and
shear values do no favor prolonged severe storms. A strong storm
or two cannot be ruled out, though. Heavy downpours will be likely
with storms today given the moisture-rich environment. Activity
will dwindle down tonight, giving way to a cloudy and muggy night
with lows in the low 70s. Patchy dense fog is likely early Sunday
morning in the few hours leading up to sunrise.

Sunday looks pretty similar to today with perhaps less coverage in
showers and storms as the frontal boundary continues to lift out of
the area. Assuming the boundary maintains a southwest to northeast
movement, the better rain chances will exist along the Plateau
again tomorrow. Again, very similar to today elsewhere with any
scattered thunderstorms capable of producing heavy rain and
frequent lightning.

&&

.LONG TERM...
(Sunday Night through next Saturday)
Issued at 1139 AM CDT Sat Jul 20 2024

The weather pattern across Middle Tennessee will remain
unsettled as we move into the new week. A very deep cut off low will
traverse Canada this week, resulting in a troughing pattern
lingering over portions of the midwest and the Ohio Valley.
Southwesterly flow embedded within this trough will help to
continuously stream in small disturbances through the week. No one
day is jumping out in terms of severe weather, but Tuesday and
Wednesday look to have a bit more activity than the other days as
a cold front moves through in association with a shortwave trough.
There will be a bit more forcing in place for storms to work
with. Still, though, model soundings do not suggest much in the
way of severe activity. The trough will finally dislodge by the
end of the week with global models hinting at higher 500mb heights
building in across the southeast by the weekend.

Main concern for the upcoming week will be monitoring the potential
for any flooding. Models keep dew point temperatures in the low 70s
with high relative humidity values, thus PWAT values will be very
healthy and conducive for heavy rain in any storms. That combined
with the repeated rounds of showers and storms will increase the
flooding threat this week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1223 PM CDT Sat Jul 20 2024

Scattered showers and thunderstorms through 03z. IFR/LIFR
conditions in any thunderstorms due to heavy rain and low vis.
Thunderstorms diminish shortly after sunset with dry conditions
overnight. Low cigs will remain over the Plateau overnight. Patchy
fog will develop overnight bringing MVFR to LIFR conditions. Light
southerly winds shifting more northerly overnight.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      72  89  71  89 /  30  60  60  60
Clarksville    68  86  68  85 /  10  40  30  50
Crossville     65  81  64  82 /  60  80  60  80
Columbia       69  88  68  89 /  30  60  50  60
Cookeville     67  83  67  82 /  50  70  70  80
Jamestown      66  81  65  82 /  50  80  60  80
Lawrenceburg   68  87  68  87 /  40  70  60  60
Murfreesboro   70  89  69  89 /  40  60  60  70
Waverly        67  86  67  86 /  20  40  30  50

&&

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

$$

SHORT TERM...Baggett
LONG TERM....Baggett
AVIATION.....Mueller