112
FXUS64 KOHX 220210 AAA
AFDOHX

Area Forecast Discussion...UPDATED
National Weather Service Nashville TN
910 PM CDT Tue May 21 2024

...New UPDATE...

.UPDATE...
Issued at 910 PM CDT Tue May 21 2024

Tweaked hourly temperature, dewpoint, wind speed/direction, and
sky condition grids blending them with previously associated
hourly gridded forecasted values. Current regional temperature
trends continue to be in line with forecasted lows. Remainder of
forecast continues to be on track.

&&

.SHORT TERM...
(This afternoon through Wednesday Night)
Issued at 1200 PM CDT Tue May 21 2024

If I were a betting man, my money would be on many people
stepping outside today and immediately saying, "It sure feels
like summer out here." They wouldn`t be wrong: dew points in the
mid to upper 60s and almost every site in Middle TN in the low 80s
at 10 am? Yeah. That`s summer. However, it`s May 21st. That means
it`s still spring and that means severe weather. Not today, but I
gotta tell you, models have starting singing a song of a very
active holiday weekend ahead. Yesterday didn`t look like much, but
it looks a lot different today.

In the short term, today will remain quiet. High pressure is
dominating the area and while some heat-of-the-afternoon cumulus
clouds will eventually develop, we should remain rain-free.
Afternoon highs will climb into the low 90s in many spots, but we
should come up short of the record 94 degrees from 1941.

We`re still looking at tomorrow being the start of our active
stretch of weather. This begins with a round of showers and
thunderstorms crossing the TN River just before sunrise tomorrow.
This first wave should be of the general variety and almost every
model shows these petering out pretty quickly -- likely only a
light shower by the time they reach the I-65 corridor. This will
start a lull in activity before the front associated this system
starts to approach mid-afternoon tomorrow. Instability is
respectable with about 30 kts of shear, so I wouldn`t write this
first round of storms off. A few strong wind gusts will be
possible (40-60 mph) with brief heavy rains through the early
evening hours.

&&

.LONG TERM...
(Thursday through next Tuesday)
Issued at 1200 PM CDT Tue May 21 2024

Each of the next several days will present thunderstorm chances, as
we talked about yesterday. What`s different is, now a few of the
days are standing out as having severe threats. At this time, if I
had to pick 3 of them, Friday, Sunday and Monday look like they`ll
have the best chance. Each show an all-severe mode threat: damaging
wind gusts, large hail and even a tornado threat, plus heavy rain.
Sharp mid-level lapse rates (8+ deg/km), 3000-4000 J/Kg CAPE, deep
layer and low-level shear, and several other parameters that are
fairly impressive, like supercell composites in the upper teens by
Sunday. However I wouldn`t sleep on Thursday or Saturday, either. In
addition, I still think the cumulative rainfall through the weekend
presents a flooding threat at some point due to PWs running 1.5-1.6
inches throughout the weekend. So, here`s the point: please remain
weather aware from tomorrow through Monday. Check back here, check
our website and our socials regularly for the latest. I have a
feeling the ol` weather bureau is gonna have a busy holiday
weekend.

&&

.AVIATION...
(00Z TAFS)
Issued at 746 PM CDT Tue May 21 2024

A surface boundary situated to our west is producing strengthening
southerly flow across Middle Tennessee, giving us plenty of warm
advection. TAFs are VFR for the overnight period and much of the
day tomorrow. We do expect some mid and high clouds to develop
over the next several hours as the boundary draws closer to the
mid state. Expect some shower development mainly during the
afternoon on Wednesday in areas west of the Cumberland Plateau.
Some storms are likely to accompany the afternoon activity, as
there will be considerable instability, and so we have included
PROB30 remarks in several of our TAFs to address the possibility
of afternoon convection.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      69  85  68  83 /  20  50  60  80
Clarksville    69  83  66  80 /  70  60  80  80
Crossville     62  80  63  76 /   0  20  40  70
Columbia       68  85  67  81 /  10  50  60  70
Cookeville     65  80  65  78 /  10  30  50  70
Jamestown      64  80  64  75 /   0  30  50  80
Lawrenceburg   67  85  67  81 /  10  50  40  60
Murfreesboro   67  85  67  82 /  10  50  40  70
Waverly        68  84  65  81 /  50  60  80  80

&&

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

$$

UPDATE.......JB Wright
SHORT TERM...Unger
LONG TERM....Unger
AVIATION.....Rose