-- Discussion containing changed information from previous version are highlighted. --
471
FXUS64 KMRX 011120
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
720 AM EDT Sat Jun 1 2024

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 236 AM EDT Sat Jun 1 2024

Key Messages:

1. Below normal highs in the southern areas, near normal for the
northern areas.

2. Most areas dry today, best chance of rain west of I-75.

3. Breezy winds tonight for the east TN mountains, gusts up to 35
mph across the highest ridgetops.

Discussion:

High pressure shifts east today as an upper level shortwave rotates
in from the west. This shortwave will be slow to move in though as
high pressure is anchored off the coast of the southeastern U.S.
Because of this, most areas will stay dry today. The best chances of
rain will be west of I-75. Precip amounts will be light across these
areas with amounts generally less than 0.1 inches. Due to very weak
elevated instability, an isolated thunderstorm is possible but
mostly showers are expected. Due to the increased cloud cover and
vicinity showers, the southern TN valley, Cumberland Plateau, and
southwest NC will see the cooler high temps today, around 10 degrees
below normal. Near normal highs are expected across northeast TN and
southwest VA due to thinner high clouds and more sunshine.

The shortwave finally rolls in tonight and brings increasing chances
of showers, and a few storms, across the area. The 850 mb winds
increase to around 30kts as the pressure gradient tightens and the
east TN mountains will see breezy winds with gusts up to 35 mph
across the higher ridgetops. Precip amounts overnight should be
light north of I-40, less than 0.1 inches. Up to 0.25 inches is
possible south of I-40.

&&

.LONG TERM...
(Sunday through Friday)
Issued at 236 AM EDT Sat Jun 1 2024

Key Messages:

1. Temperatures near to slightly above normal are expected Monday
through Wednesday, trending more mild late next week.

2. Daily chances of showers and storms exist throughout the
extended.

Discussion:

A weakening surface boundary and upper shortwave will allow for the
chance of showers and storms to persist into Sunday. Sifting through
various models, surface based CAPE is expected to range around 750-
1250J/kg Sunday afternoon. With no shear expected due to a lack of
upper level features, just general summer time activity is expected.

Shortwave ridging will limit coverage of a more diurnal trend in
showers & storms to be more isolated in nature, with the best
chances(30-40%) across higher terrain of the East Tennessee
mountains Monday. Again, just general run-of-the-mill activity
expected among a warming trend.

Vort lobes will swing across the area associated with additional
disturbances Tuesday into the late week, allowing for daily chances
of showers and storms to persist. An additional frontal boundary may
approach the region Tuesday through Wednesday and result in
heightened coverage of showers and storms. Ensemble guidance trends
towards increasing instability with this activity so perhaps a
stronger storm with gusty winds and small hail cannot be ruled out.
Additionally, ensemble guidance suggest around 50-70% chance of PWAT
greater than 1.5" around this time as well, so will keep an eye on
potential for hydro issues depending on how repeated rounds of
rainfall play out. Overall, nothing looks too concerning / confident
enough this far out so will continue to utilize low probability in
the HWO for the time being. Temperatures will trend cooler Thursday
and Friday.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 642 AM EDT Sat Jun 1 2024

TYS and TRI should remain VFR through the period with winds less
than 10kts, generally out of the south. CHA is more challenging.
Not sure how long MVFR CIGs will hold off today with precip just
west of the terminal. Worst case, MVFR CIGs occur a little earlier
than forecast. Best case, MVFR CIGs hold off until later this
evening. Winds will be out of the south, with gusts to 20kts
through mid to late afternoon. Also, held thunder out until
tonight but it`s possible CHA records a VCTS this afternoon.
-- End Changed Discussion --

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             74  63  82  66 /  50  70  40  10
Knoxville McGhee Tyson Airport, TN  78  61  79  64 /  10  50  50  10
Oak Ridge, TN                       75  60  78  63 /  30  60  50  10
Tri Cities Airport, TN              78  58  76  61 /  10  60  70  20

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

$$

SHORT TERM...
LONG TERM....KRS
AVIATION...