Johnson City, Tennessee 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

053
FXUS64 KMRX 041818
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
218 PM EDT Sat Jul 4 2026

...New DISCUSSION...

.KEY MESSAGES...
Updated at 218 PM EDT Sat Jul 4 2026

- Hot temperatures will continue through the weekend before
subsiding next week. Continue to take precautions, find shade, and
drink plenty of water.

- Shower and storm activity is expected mainly along and near the
East Tennessee mountains, Northeast Tennessee and Southwest Virginia
this afternoon. Elsewhere, activity will be more isolated this
afternoon, possibly becoming more scattered this evening.

- Showers and storms will be more widespread Sunday afternoon and
evening as a shortwave approaches.

- Continued diurnal storm activity combined with regular summer heat
next week.

&&

.DISCUSSION...
Issued at 218 PM EDT Sat Jul 4 2026

Radar was more active than expected this morning as an outflow
boundary moved through the region.  Current radar shows showers and
storms near the East Tennessee/North Carolina mountains and also in
Southwest Virginia/Northeast Tennessee. CAMs seem to be getting back
on track with the current placement of storms. The previous run of
CAMs had mountain storms moving into the Central TN Valley and
Northeast TN this evening. The latest run has isolated to scattered
activity mainly in the Central TN Valley this evening. Some CAMs
don`t have storms dissipating completely until after midnight. With
the hit and miss nature of this activity, impacts on outdoor
activities will not be widespread. Confidence is low on shower/storm
coverage this afternoon/evening.

Storms will dissipate around or shortly after midnight. Sunday
afternoon and evening showers and storms will be scattered to
widespread as a trough moves into the Ohio Valley centered near
IL/IN Sunday afternoon. A Marginal risk for severe can be expected
in the afternoon and evening hours with good instability in place
with CAPE around 1k to 2k J/kg. Heavy rain can also be expected
locally with PWat values close to 2 inches and weak steering flow.

A trough will be over the Ohio Valley early next week bringing
widespread showers and storms in the afternoon/evening hours. By
midweek, a ridge builds into the region briefly before a broad
trough moves in late in the workweek. The best energy will likely
stay to the north but widespread diurnal thunderstorms seem likely
for most of next week. Temperatures will still be hot but much
closer to normal for July.

&&

.AVIATION...
(18Z TAFS)
Issued at 123 PM EDT Sat Jul 4 2026

Showers and thunderstorms are expected to be isolated this
evening. Fog is possible in the early morning hours but confidence
is low since none of the terminals have had a significant rain
today. Showers and storms will be more widespread tomorrow,
although likely just after this timeframe.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             75  95  74  91 /  40  60  40  50
Knoxville McGhee Tyson Airport, TN  73  93  73  90 /  70  60  40  50
Oak Ridge, TN                       73  93  72  90 /  60  60  40  50
Tri Cities Airport, TN              70  93  69  89 /  50  60  30  50

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Heat Advisory until 8 PM EDT this evening for Cherokee-Clay.

TN...Heat Advisory until 8 PM EDT /7 PM CDT/ this evening for
     Anderson-Bledsoe-Blount Smoky Mountains-Bradley-Campbell-
     Claiborne-Cocke Smoky Mountains-East Polk-Grainger-Hamblen-
     Hamilton-Hancock-Hawkins-Jefferson-Johnson-Knox-Loudon-
     Marion-McMinn-Meigs-Morgan-North Sevier-Northwest Blount-
     Northwest Carter-Northwest Cocke-Northwest Greene-Northwest
     Monroe-Rhea-Roane-Scott TN-Sequatchie-Sevier Smoky
     Mountains-Southeast Carter-Southeast Greene-Southeast
     Monroe-Sullivan-Unicoi-Union-Washington TN-West Polk.

VA...Heat Advisory until 8 PM EDT this evening for Lee-Russell-Scott
     VA-Washington VA-Wise.

&&

$$

DISCUSSION...McD
AVIATION...McD