856
FXUS64 KOHX 140140
AFDOHX

Area Forecast Discussion
National Weather Service Nashville TN
840 PM CDT Mon May 13 2024

...New UPDATE...

.UPDATE...
Issued at 829 PM CDT Mon May 13 2024

Nice and quiet at update time this evening. Light sprinkly rain
has moved out of here and into KY and these quiet conditions are
expected for the next several hours. However, before sunrise, CAMs
continue to develop showers and thunderstorms in our west,
traversing the mid-state through the mid-morning hours. These
should be garden-variety storms, but will likely produce brief
heavy rain and some decent rumbles of thunder.

CAMs also want to develop a second round of storms for the
afternoon/evening hours tomorrow. If you didn`t see, SPC spread a
Marginal Risk over the entire mid-state tomorrow, and from the
looks of it, for good reason. I don`t expect anything widespread
in the severe category, but after pouring over forecast soundings,
they are proving to be interesting. Lapse rates approaching 7.0
deg/km, CAPE values in the 1200-1500 J/Kg range and several
algorithm parameters suggesting the potential for a couple strong
to severe wind gusts tomorrow. However, there are a couple of
limiting factors, from what I`m seeing. Shear is lacking. Not
greatly lacking, but 20 kts of deep layer shear is barely enough
to get thunderstorms going, let alone sustain updrafts. We`ll see
how the shear pans out, but I would remain weather aware tomorrow,
especially if you have outdoor plans. Like I said, it shouldn`t be
anything widespread, but I would not be surprised for the need
for a couple severe warnings for wind tomorrow afternoon.

&&

.SHORT TERM...
(Rest of today through Tuesday)
Issued at 1122 AM CDT Mon May 13 2024

It`s pretty cool out there this morning with temps in the low to
mid 60s. Current radar imagery shows some very light and
scattered precip across the area. I would be surprised if any of
it was making it to the ground, though, as this morning`s balloon
launch shows a large dry layer above us. As the upper-level low
continues to scoot in, moisture will fill in and rain will likely
start making it to the ground this afternoon. The scattered
activity will continue through the afternoon. Instability should
stay on the low side, but can`t rule out a few rumbles of thunder
today.

For tonight, the latest CAMs are showing a line of thunderstorms
developing across west Tennessee overnight tonight around 3 to 4
am and pushing east through the area during the morning hours
Tuesday. While there won`t be much instability around during that
time, there could still be some thunder. Models show a second line
developing between 12pm-2pm Tuesday afternoon that could bring a
marginal severe threat, particularly to areas south of I-40.
Right now, the main threats with that line appear to be small hail
and damaging winds. I know with the recent bout of severe
weather, that`s not what people want to hear. On the plus side,
Tuesday looks like the only day (for now at least) of any
consequence...And the threat is marginal. 0-6km shear values will
be pretty low, lapse rates aren`t great (around 6 C/Km), and mean
instability is around 1400 J/KG.

Something else worth noting is that there could be a few heavy
downpours with PWAT values near 1.40" tomorrow. While flooding
isn`t a great concern, it will be something to monitor since the
ground is still so saturated and a few waterways are still very
full. That previous sentence goes for the whole forecast package,
both now and through the long term. Rainfall amounts Monday-
Wednesday will be anywhere from 0.5" to 1".

&&

.LONG TERM...
(Tuesday Night through next Monday)
Issued at 1122 AM CDT Mon May 13 2024

Scattered activity will continue through Tuesday night and will
be slow to exit off the Plateau on Wednesday. We`ll have some more
scattered activity around as the surface low spins NE out of the
area. Looking aloft, ridging will start building in late Wednesday
night. This will provide temporary relief from the rain for at
least Thursday. This upper-air pattern is a progressive one,
though, and another upper-level low developing over the SW will
start pushing this way through the rest of the forecast period.
This translates to an active and unsettled weather pattern for the
weekend. Forecast rainfall amounts for Friday-Sunday range
anywhere from 0.5" to near 2".

Temperatures in the extended period will generally be in the low
80s for highs and overnight temps in the 60s.

&&

.AVIATION...
(00Z TAFS)
Issued at 642 PM CDT Mon May 13 2024

Showers have been very light out there this evening, limited to
some sprinkles. The remainder of tonight will be on the drier side
before a line of showers and thunderstorms move through Tuesday
morning. By the afternoon, convection looks to increase bringing
more showers and thunderstorm through Tuesday evening. CIGs are
lowering down to MVFR this evening with some periods of IFR
expected tonight. These conditions remain through Tuesday with
some reduced VIS with any heavier showers. Winds are coming in a
little weaker than expected between 10 to 12 kts and will weaken
through the night. Tuesday`s winds remain out the S around 10 kts
but could become gusty with any stronger thunderstorms that
develop.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      64  78  62  78 /  80  70  80  60
Clarksville    62  77  61  75 /  80  70  70  40
Crossville     57  71  58  70 /  40  70  90  80
Columbia       63  77  61  78 /  80  70  70  50
Cookeville     60  74  60  72 /  50  80  90  80
Jamestown      57  73  58  70 /  30  60  90  80
Lawrenceburg   63  77  61  77 /  80  70  70  50
Murfreesboro   62  77  61  77 /  80  70  80  60
Waverly        62  76  61  76 /  80  70  70  40

&&

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

&&

$$

UPDATE.......Unger
SHORT TERM...Baggett
LONG TERM....Baggett
AVIATION.....Cravens