Knoxville, Tennessee 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

233
FXUS64 KMRX 111913
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
313 PM EDT Fri Apr 11 2025

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Saturday)
Issued at 300 PM EDT Fri Apr 11 2025

Key Messages:

1. Showers and a few thunderstorms continue this evening, ending
around midnight.

2. Patchy frost possible tonight, and light snow accumulation in the
mountains above 4000 ft.

3. Decreasing clouds Saturday but below normal temperatures continue.

Discussion:

Satellite and radar show that the closed midlevel cyclonic
circulation has moved to our eastern border, near the TN/NC/VA
corner. It will continue to progress eastward tonight. With the exit
of the low and the loss of daytime heating, most of the shower
activity will come to an end. Through the rest of the afternoon and
evening, numerous showers and isolated thunderstorms will continue,
and a few reports of small hail will be possible due to the low
freezing level. With the low freezing level and an NW flow, some
light snow accumulation will be possible in the mountains, mainly
less than 1 inch and mainly above 4000 ft.

Partial clearing will occur late tonight, mainly in southern and
western sections. This may allow for temperatures to drop in the
lower to mid 30s, if winds drop off enough. Some light wind is
expected, so conditions will not be ideal for widespread frost, but
patchy frost will be possible in sheltered valleys. Might be a good
idea to cover up sensitive plants tonight, just to be safe.

Saturday will have decreasing clouds as high pressure builds over
the area from the surface through the upper levels. Morning clouds
will linger in NE sections but should erode in the early afternoon
with mixing and dry advection. Cold advection will continue however,
thank to a north wind, and highs will be in the 50s to lower 60s
again.

&&

.LONG TERM... (Saturday night through Friday)...

Key Messages:

1. Possible widespread frost Sunday morning with freeze across parts
of southwest Virginia, southwest North Carolina, and far east
Tennessee mountains.

2. Trending dry Saturday night and Sunday with temperatures
increasing at the beginning of the week.

3. Cold front Monday night into Tuesday brings next chance of
showers and storms.

4. Frost possible again early Wednesday and Thursday.

5. Late Thursday and Friday another chance of showers and storms.

Discussion:

Temperatures will be going up and down for the extended. This is due
to rapid pattern changes. Deep upper trough that is exiting the
forecast area including the southern Appalachians late Saturday will
be replaced by ridging building into the Tennessee valley and
southern Appalachians by Sunday.

Then with the surface ridging, good radiational cooling and light
winds. Cold temperatures are forecast Saturday night. A freeze is
possible across the far east Tennessee mountains, southwest
Virginia, and southwest North Carolina, and temperatures a little
above freezing and patchy frost elsewhere. Sunday the developing
upper ridge should produce mostly dry conditions and warmer
temperatures.

Sunday night and Monday the ridge begins to flatten with the surface
ridge moving east. One model brings a quick shortwave through Sunday
night with a chance for showers. The model consensus is though that
a new upper trough to move into the Great Lakes Monday and then
eastern states Tuesday. A cold front will move into the Ohio Valley
Monday from a deep surface low over the Great Lakes and spread
clouds and showers and thunderstorms into the Tennessee Valley and
southern Appalachians Monday night and Tuesday. Rainfall amounts are
expected to be low with this front as gulf moisture return is too
limited. Also the main energy with this system will be far to the
north over the Great Lakes and upper Ohio Valley.

Wrap around moisture behind this system will be moving out Tuesday
night. Some patchy frost is possible early Wednesday if clouds move
out and winds decrease enough. Wednesday night, surface ridging and
a cool airmass will produce some more frost early Thursday.

Late Thursday into Friday, another quick moving short-wave in the
northwest flow will move across the Tennessee valley into the
southern Appalachians. There should be enough instability moving
back into the area for some convection late Thursday and again
Friday. Confidence is still low for any potential of
significant storms.

&&

.AVIATION...
(18Z TAFS)
Issued at 112 PM EDT Fri Apr 11 2025

Showers will be scattered to numerous around the area through the
evening. Prevailing VFR conditions are expected at all sites, but
a passing shower may bring brief MVFR conditions. TS cannot be
ruled out entirely but the chance is too low to mention. MVFR cigs
will persist overnight before gradually lifting/scattering
tomorrow morning as drier air builds in.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             41  64  37  72 /  20   0   0   0
Knoxville McGhee Tyson Airport, TN  37  59  36  70 /  20   0   0   0
Oak Ridge, TN                       36  60  35  69 /  10   0   0   0
Tri Cities Airport, TN              36  55  33  66 /  20   0   0   0

&&

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

$$

SHORT TERM...DGS
LONG TERM....TD
AVIATION...DGS