Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN

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821
FXUS64 KMRX 171733
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
133 PM EDT Tue Jun 17 2025

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 239 AM EDT Tue Jun 17 2025

Key Messages:

1. Scattered showers and thunderstorms mainly this afternoon
into the evening will bring gusty winds and locally heavy rain.

Discussion:

A few showers and thunderstorms were ongoing at publish time
generally north of I-40. This activity will continue for the next
few hours. A persistent forecast will continue today with similar
conditions to yesterday. Some might say we sound like a broken
record lately. The muggy conditions will lead to efficient rain
makers in the afternoon and evening hours again. This is spurred by
a weak upper level trough and southwest flow aloft. Locally heavy
rainfall and wind gusts as high as 40 mph will be the main impacts
today and tonight.

&&

.LONG TERM...
(Wednesday through Monday)
Issued at 239 AM EDT Tue Jun 17 2025

Key Messages:

1. Storms are possible mainly each afternoon the rest of the week
during peak heating. Gusty winds and heavy rainfall are the main
concerns.

2. Weekend warm up with heat index values approaching 105 degrees
particularly in the southern TN Valley.

Discussion:

On Wednesday, little change to the atmosphere and antecedent
conditions leading to a carbon copy of Tuesday`s weather. A deeper
trough will move eastward Wednesday night and help push a weak cold
front into the region Thursday. Moderate instability, abundant
moisture, steeper low level lapse rates and deep layer shear could
produce a few wind gusts exceeding 58 mph Thursday
afternoon/evening. Locally heavy rainfall will also be likely given
the high PW values.

The focus shifts to some drier days with warming temperatures into
the weekend. By the end of the weekend, heat indices approach 100-
105 degrees across the southern Tennessee Valley into early next
week. Afternoon showers and thunderstorms will return to the
forecast Monday afternoon.

&&

.AVIATION...
(18Z TAFS)
Issued at 121 PM EDT Tue Jun 17 2025

Scattered showers are expected across the region this afternoon
with the highest probability of thunder at CHA where vcts is
mentioned. Otherwise, included Prob30 groups for tsra at TYS and
TRI through the evening hours. Overnight, vcsh continues with
mentions of MVFR cigs and vis potential at all sites through
Wednesday morning due to low clouds and fog potential, mainly
between 08z and 12z Wednesday.


&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             70  87  71  85 /  60  60  40  90
Knoxville McGhee Tyson Airport, TN  71  86  71  83 /  70  60  40  90
Oak Ridge, TN                       69  85  70  83 /  70  60  40  90
Tri Cities Airport, TN              67  84  67  83 /  60  60  20  90

&&

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

$$

SHORT TERM...
AVIATION...JB