-- Discussion containing changed information from previous version are highlighted. --
365
FXUS64 KOHX 081130
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
630 AM CDT Wed May 8 2024

...New AVIATION...

.SHORT TERM...
(Today through Thursday)
Issued at 125 AM CDT Wed May 8 2024

All eyes are on today`s forecast as all modes of severe weather
including flash flooding are anticipated across Middle
Tennessee. I`ll be honest, things are very complex and not clear
cut, so it`s imperative for everyone to be weather aware all day
today into tonight. This is not a "one and done" type of event.
Multiple thunderstorms at multiple parts of the day will have the
opportunity to be severe. If you are going to be out and about
today and tonight, it`s imperative for you to check the weather
before heading out and have multiple ways to get notified when
warnings are issued.

Here`s what we`re confident on:
1) The potential for flash flooding has been increasing with each
model run and even though we didn`t get much in the way of
rainfall on Tuesday, this system has the unfortunate opportunity
to place a boundary over Middle Tennessee where ample moisture
will allow thunderstorms to train over the same locations over and
over and over. This boundary will likely set up near or north of
I-40, but there`s even a possibility that it sets up in Southern
Kentucky (and Middle Tennessee skirts away from the highest
precipitation totals). But wherever that boundary sets up, heavy
rainfall and flash flooding will result.

2) There will be some impressive straight line winds along with
some potential QLCS tornadoes when the main/final line of storms
pushes through late tonight. There`s definitely much more
uncertainty on how things unfold before this main line. Timing
things during the daylight hours is extremely difficult, but the
main line should move through after dark.

3) Lapse rates are also high so think any storm that develops
today through tonight will have the potential to produce large
hail.

4) Don`t be fooled by any morning or early afternoon convection
being "the event" or limiting things. The main line coming through
tonight will pack quite the punch that won`t care if you did or
didn`t have storms earlier in the day.

Here`s what we`re not confident on:
1) Speaking of the boundary, exactly where this will set up will
be the million dollar question. Short range models are having a
difficult time initializing correctly over our area during this
overnight period, so confidence on how everything will exactly
play out today is not very high. Regardless, all the parameters
you always hear meteorologists spout off during big severe weather
events are all there with ample moisture, instability, and shear.

2) If discrete supercells can develop this afternoon and evening,
this would spell big trouble for the tornado threat and increase
the severe weather potential significantly. Think this concern is
mostly for the northern half of Middle Tennessee but once again,
it all depends on where exactly the above mentioned boundary sets
up.

It`s Spring in Middle Tennessee. We want you to be prepared and
not scared. Today and tonight is when we need you to pay attention
to the weather as things will be rapidly evolving throughout the
day.

By Thursday morning, storms rapidly move south of Tennessee giving
way to drier conditions and partly cloudy skies.

&&

.LONG TERM...
(Thursday Night through next Wednesday)
Issued at 125 AM CDT Wed May 8 2024

Friday and this weekend look fairly nice weather wise as Highs in
the 70s and Lows in the 40s and 50s will be the main weather
story. There will be some northwest flow aloft and some model solutions
do have some weak upper level impulses swinging through the area.
Kept things dry for now, but would not be surprised to see some
increases in cloud cover and possible showers.

Another upper level trough will impact the area on Monday and
Tuesday as return flow brings the southerly flow and moisture
back. Showers and thunderstorms will return to the forecast, but
nothing looks impactful at this time.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 626 AM CDT Wed May 8 2024

Messy aviation forecast today with TSRA in the area through much
of the current TAF period. Current line of TSRA will likely begin
to stall around the I-40 corridor, so some vis impacts as that
line progresses. Rest of the day will have scattered TSRA, with
periods of low cigs/vis. Final line of TSRA will move through
around to after 03Z from NW to SE, with conditions beginning to
improve near to after the current TAF period. Winds will remain
predominately from the south.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
-- Changed Discussion --
Nashville      84  69  84  58 /  90  90  30  10
Clarksville    82  68  82  55 /  90  90  10  10
Crossville     79  63  78  53 /  90  80  60  20
Columbia       85  66  85  55 /  80  90  40  10
Cookeville     80  65  80  54 /  90  90  50  10
Jamestown      80  63  78  53 /  90  90  50  20
Lawrenceburg   84  66  84  56 /  70  90  40  20
Murfreesboro   85  66  84  55 /  90  80  40  10
Waverly        82  65  83  55 /  90  90  20  10
-- End Changed Discussion --

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
Flood Watch through Thursday morning for Bedford-Cannon-Cheatham-
Clay-Coffee-Cumberland-Davidson-De Kalb-Dickson-Fentress-Grundy-
Hickman-Houston-Humphreys-Jackson-Lewis-Macon-Marshall-Maury-
Montgomery-Overton-Perry-Pickett-Putnam-Robertson-Rutherford-
Smith-Stewart-Sumner-Trousdale-Van Buren-Warren-White-Williamson-
Wilson.
-- End Changed Discussion --

&&

$$

SHORT TERM...Hurley
LONG TERM....Hurley
AVIATION.....Adcock