534
FXUS64 KOHX 261706
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
1206 PM CDT Thu Sep 26 2024

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(Rest of today through Sunday)
Issued at 1200 PM CDT Thu Sep 26 2024

Hurricane Helene is the big weather story and will be the main
impact on our local wx over the next couple of days. The mid
morning update had the center of Helene located 255 miles
southwest of Tampa with max sustained winds of 105 mph. Helene is
expected to make landfall in the Florida Big Bend region this
evening as a large, major Hurricane. The storm will move north
then northwest, weakening to a tropical depression as it moves
over Middle Tennessee and hangs around late Friday through
Saturday.

The main impacts for Middle Tennessee will be heavy rainfall
possibly causing localized flooding and gusty winds with
potential for a few downed trees and scattered power outages. We
have our entire coverage area under a Flood Watch and Wind
Advisory, both from 7 PM this evening until 7 AM Saturday.

Models have remained in pretty good agreement with the general
scenario, moving Helene toward Middle Tennessee, interacting with
a big cutoff low just to our west. Then the low pressure systems
will spin around and merge. A surge of tropical moisture will
precede the main center of Helene causing rain to spread quickly
across the area later today through tonight. Rain will become
heavy at times. As the center of Helene moves closer, winds will
increase with frequent gusts of 20 to 30 mph.

For rainfall, the heaviest and most widespread rain will occur
tonight through midday Friday. During this time, most areas are
expected to have 2 to 3 inches of rain with locally higher totals.
Additional on and off rain is then expected Friday night through
the weekend. Event totals will be mostly in the 2 to 4 inch range
with some areas up to 5 or 6 inches. By Sunday, there will be a
notable decease in coverage of showers as the low weakens and
starts to move out the area. Flooding is expected to be generally
localized, impacting roads and low lying areas. Small streams will
rise, some possibly reaching bankfull. Main rivers are expected
to handle the rainfall without reaching flood stage.

For winds, the strongest winds will occur in the early morning
hours Friday with another peak late Friday as low center
repositions and shifts wind directions from mainly north to
mainly south. Generally, the strongest gusts are expected across
our northeast half (generally along and northeast of I-24) with
some episodes of 40 to 45 mph gusts. Our southwest counties may
not reach advisory level, but given uncertainties about the
wobbling track, we decided to include all areas in the advisory.

Thankfully, parameters for severe storms and tornadoes are
looking low thanks to extensive coverage of showers and clouds.
Still, the setup is a little unusual and we may have a few pockets
of storms this weekend in areas of partial clearing or within
heavier rainfall bands. Very low risk, but something to keep in
mind.

&&

.LONG TERM...
(Monday through next Thursday)
Issued at 1200 PM CDT Thu Sep 26 2024

Some straggling showers may occur Monday, then we may have a few
showers with a cold front Tuesday. Otherwise the trend for next
week is for dry wx with seasonable temperatures.

&&

.AVIATION...
(12Z TAFS)
Issued at 612 AM CDT Thu Sep 26 2024

We`ve got some messy weather coming in as Hurricane Helene inches
closer to shore. We start off the day with  fog and low stratus
along and adjacent to the Cumberland Plateau. Light showers will
work their way into the mid state by this afternoon and will
spread westward during the afternoon and evening. As this
develops, look for IFR ceilings to settle in as well, and winds
are going to pick up considerably during the afternoon and
especially overnight as the surface pressure gradient gets wound
up.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      80  67  74  63 /  50 100 100 100
Clarksville    80  65  73  62 /  40 100 100 100
Crossville     70  60  69  57 /  90 100 100 100
Columbia       79  63  71  61 /  40 100 100  90
Cookeville     72  63  70  61 /  90 100 100 100
Jamestown      70  63  70  59 /  90 100 100  80
Lawrenceburg   79  63  70  61 /  50 100 100  90
Murfreesboro   79  65  72  62 /  60 100 100  90
Waverly        81  63  71  59 /  30 100 100 100

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 7 PM CDT this evening through Saturday morning
for Bedford-Cannon-Cheatham-Clay-Coffee-Cumberland-Davidson-De
Kalb-Dickson-Fentress-Giles-Grundy-Hickman-Houston-Humphreys-
Jackson-Lawrence-Lewis-Macon-Marshall-Maury-Montgomery-Overton-
Perry-Pickett-Putnam-Robertson-Rutherford-Smith-Stewart-Sumner-
Trousdale-Van Buren-Warren-Wayne-White-Williamson-Wilson.

Wind Advisory from 7 PM this evening to 7 AM CDT Saturday for
Bedford-Cannon-Cheatham-Clay-Coffee-Cumberland-Davidson-De Kalb-
Dickson-Fentress-Giles-Grundy-Hickman-Houston-Humphreys-Jackson-
Lawrence-Lewis-Macon-Marshall-Maury-Montgomery-Overton-Perry-
Pickett-Putnam-Robertson-Rutherford-Smith-Stewart-Sumner-
Trousdale-Van Buren-Warren-Wayne-White-Williamson-Wilson.

&&

$$

SHORT TERM...13
LONG TERM....13
AVIATION.....Rose