Severe Thunderstorm Warning 155, NWS Nashville, TN

Area Forecast Discussion
National Weather Service Nashville TN
1238 PM CDT Thu May 8 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 1237 PM CDT Thu May 8 2025

- High chance (70 to 80 percent) for showers and thunderstorms
  this afternoon and evening. Slight risk (level 2 out of 5) for
  severe storms with damaging wind gusts and large hail. Very low
  risk for tornadoes.

- Forecast has improved for the weekend, now expected to be mostly
  rain-free with pleasant temperatures.

- Unsettled conditions return Monday and Tuesday with a medium to
  high chance for showers and thunderstorms. No severe storms
  expected at this time.

&&

.SHORT TERM...
(Rest of today through Friday)
Issued at 1120 AM CDT Thu May 8 2025

Almost all of the Mid State remains under a slight risk for severe
storms this afternoon and early evening. This is a setup where no
single forecast parameter jumps out with extreme values, but there
are several parameters, that taken together, are good enough to
bring a risk for damaging winds and large hail.

We have held onto a lot of fog and low clouds this morning, but
things are finally starting to mix out and we are already seeing
some storms fire up over West TN. As more sunshine is revealed,
capes should climb to "moderate levels" 1500-2000 J/kg. Deep
layer shear values will be good enough for some organized storm
clusters and perhaps a few supercells. Low level shear/helicity
does not support much tornado risk. Forecast soundings show steep
low level lapse rates with an inverted V appearance indicating
potential for damaging wind gusts. Wet bulb zero level below 9kft
and elevated significant hail parameter values support possibility
of hail up to 2 inches in the strongest updrafts.

Falling heights with the approach of a low pressure currently over
southern Missouri and low level convergence with a frontal zone
sinking southward from the Ohio Valley will help initiate deep
convection. It looks like scattered storms will begin to form shortly
after noon in our western counties, then coverage will gradually
increase and shift eastward, perhaps coming together as an MCS
over the eastern half of our area by 6 PM. It looks like
individual cells will move east northeast around 35 mph.

Most of the showers and storms will move east of our area by 10
PM. Given a lot of leftover moisture and an initially sluggish
frontal push, there will be areas of dense fog and stratus tonight
into Friday morning.

Friday will start with areas of fog and mostly cloudy skies.
Gradually through the day, dry high pressure over the Midwest
will push into the area with stronger, drier north winds. This
should allow most areas to see some sunshine by late day.

&&

.LONG TERM...
(Friday Night through next Thursday)
Issued at 1120 AM CDT Thu May 8 2025

A notable change from the previous forecast is a better, drier
weekend. Models have trended farther south with the zone of deep
moisture and impacts from another cutoff upper level low. The
forecast shows some small pops creeping up into our area Sunday,
but most of us will probably enjoy a completely rain-free weekend.
Normal highs now are in the 70s with normal lows in the low to
mid 50s. We will be just slightly cooler than normal this weekend,
but I think most would call it very pleasant. There will be a
slightly gusty northeast wind Saturday, so outdoor activities
might feel just a bit chilly.

The second upper low mentioned earlier will move north from the
Lower Ms Valley Monday through Tuesday with another period of
unsettled showery wx. There will be enough instability for some
thunder each day, but severe potential looks very low.

Later in the week, the upper low will move out and heights will
risk, allowing rain chances to drop and high temps to jump up
well into the 80s.

&&

.AVIATION...
(18Z TAFS)
Issued at 1237 PM CDT Thu May 8 2025

Scattered showers and thunderstorms will push into the western
part of the area after 18z and work east through 05z. IFR/LIFR can
be expected with any thunderstorms due to low vis and low cigs.
IFR/LIFR cigs build back in later in the evening into the
overnight. Patchy dense fog develops after 08z and will bring
IFR/LIFR conditions. Southwesterly winds up to 10 knots will shift
north after 00z and become light.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      58  74  50  74 /  40  10   0  10
Clarksville    57  73  48  73 /  40   0   0   0
Crossville     53  69  45  70 /  80  20  10  10
Columbia       57  73  49  72 /  40  20  10  10
Cookeville     56  70  47  71 /  70  10   0  10
Jamestown      53  69  44  70 /  80  20   0  10
Lawrenceburg   57  73  49  72 /  50  10  10  10
Murfreesboro   57  73  49  73 /  50  10  10  10
Waverly        56  73  49  72 /  40  10   0  10

&&

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

SHORT TERM...13
LONG TERM....13
AVIATION.....Mueller