656
FXUS64 KOHX 240545
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
1245 AM CDT Tue Sep 24 2024

...New AVIATION...

.UPDATE...
Issued at 816 PM CDT Mon Sep 23 2024

There`s just a couple showers remaining in the area after an
afternoon of scattered showers and storms. While there were plenty
that did not get any much needed rain, MRMS does show some swaths
of 0.5"+. The heaviest amounts fell along the TN/KY border where a
few lucky folks got over an inch. A couple showers will be
possible overnight especially as we get closer to dawn. Coverage
will increase on Tuesday as instability increases. A couple severe
storms look possible in the afternoon with 35-45 kts of 0-6 km
bulk shear and 1000-2000 J/kg of mlCAPE. Damaging winds will be
the primary threat. Overall the forecast is on track and no major
changes were made with the update.

&&

.SHORT TERM...
(Rest of today through Tuesday)
Issued at 1200 PM CDT Mon Sep 23 2024

We expect a little more coverage of showers and storms this
afternoon than yesterday thanks to falling heights, stronger
shear, and perhaps some weak mid level impulses. A storm or 2 may
become briefly severe with gusty winds, but mid level lapse rates
are still unimpressive. Generally greater coverage of showers and
storms is expected north of I-40 with very low coverage down
toward the Alabama border.

A few showers or storms will linger tonight as deep southwest flow
develops ahead of an approaching trough. On Tuesday, coverage
will ramp up more as a surface front pushes into the area. A few
afternoon storms could be briefly severe with gusty winds. SPC has
our area under a marginal risk (1 out of 5). The additional
clouds and rain coverage will knock highs down a few degrees for
Tuesday.

&&

.LONG TERM...
(Tuesday Night through next Monday)
Issued at 1200 PM CDT Mon Sep 23 2024

The extended forecast continues to look unsettled with daily rain
chances. The front arriving Tuesday will stall out midweek as a
couple of big systems start to come into play. The first will be
a developing upper level low pressure system over Arkansas and the
other will be a likely tropical system coming up from the eastern
Gulf of Mexico. The tropical system is currently in the
strengthening stages and is expected to become strong Hurricane
Helene before moving onshore along the Florida Gulf Coast. The
storm will then gradually weaken as it gets lifted northward
between the upper level low over Arkansas and an upper ridge over
the Atlantic. The tropical low and mid latitude low are expected
to merge over the region this weekend keeping rain chances going
throughout the forecast period. The highest probabilities for
soaking rain in our area are shown Thursday into Friday as the
biggest slug of tropical moisture lifts across the area.

Our latest rainfall forecast shows generally 2 to 4 inches of
rain by Saturday with the higher totals over the Plateau.
Obviously there is a lot of uncertainty with this forecast
involving a tropical systems, so we could end up with lower or
perhaps higher totals. Localized flooding could be a concern
Thursday into Friday. Also, gusty winds and localized severe
storms cannot be ruled out, but there is far too much uncertainty
at this time to say what that risk level will be.

&&

.AVIATION...
(06Z TAFS)
Issued at 1241 AM CDT Tue Sep 24 2024

The 06Z TAFs are starting off VFR, but there is the possibility of
some radiation fog at our eastern terminals (CSV, SRB) overnight.
Meanwhile, an upper trough has set up west of Mississippi Valley,
and a surface low pressure system is now developing near STL that
is providing the focus for some ongoing convection in that
proximity. The HRRR does show at least some scattered cells
developing across Middle Tennessee toward morning, with more
widespread convection expected this afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      86  67  79  65 /  70  40  50  50
Clarksville    82  62  78  61 /  70  20  30  40
Crossville     83  61  74  59 /  70  80  80  70
Columbia       86  64  78  61 /  70  40  60  50
Cookeville     83  63  75  62 /  70  60  70  70
Jamestown      82  62  74  61 /  80  70  70  70
Lawrenceburg   87  64  76  61 /  70  50  60  50
Murfreesboro   87  66  78  63 /  70  50  60  60
Waverly        82  62  77  60 /  60  20  30  40

&&

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

$$

UPDATE.......Reagan
SHORT TERM...13
LONG TERM....13
AVIATION.....Rose