300
FXUS64 KMRX 011830
AFDMRX

Area Forecast Discussion
National Weather Service Morristown TN
130 PM EST Mon Dec 1 2025

...New UPDATE...

.KEY MESSAGES...
Updated at 126 PM EST Mon Dec 1 2025

- Gusty mountain winds and widespread rain arrive tonight through
  Tuesday morning. Far northeast mountains, including higher
  elevations of southwest Virginia, may begin as light freezing
  rain tonight. Minimal to no localized impacts expected. Only a
  cold rain expected for most areas.

- A changeover to sleet and then snow will occur Tuesday morning
  into afternoon across higher elevations of East Tennessee and
  southwest Virginia. Limited accumulations at most. Little to no
  impacts.

- Dry Wednesday, precipitation chances increasing late Thursday
  into next weekend with multiple systems. Light precipitation
  amounts probable.

&&

.UPDATE...
Issued at 126 PM EST Mon Dec 1 2025

Issued a Wind Advisory for Blount, Sevier, Cocke, Greene, Unicoi,
and Carter mountain zones for low-end mountain wave winds tonight.
850mb LLJ will be around 50 kt with a favorable pressure gradient
for mountain wave winds across the mountains. The HRRR is picking
up on this and showing 40-45 mph gusts in the Smokies and up to
50mph gusts near Camp Creek in Greene County. The primary timing
will correspond to the axis of max winds within the LLJ between
04z and 11z overnight into early Tuesday morning; therefore, the
Wind Advisory will be in effect for the aforementioned mountain
zones between 11pm and 6am tonight.

JB

&&

.DISCUSSION...
Issued at 1123 AM EST Mon Dec 1 2025

A strong shortwave trough moves east across the Great Plains this
evening and tonight with an upper-level dual-jet structure
developing across the region with strong, widespread upper-level
diffluence and ascent across the Tennessee Valley and Southern
Appalachians. The 850mb southerly LLJ will increase in response to
this ascent with a warm nose developing around 5-7k ft. Most of
our lower elevations will be above freezing with temperatures in
the mid to upper 30s, but localized mountain valleys and higher
elevations along the TN/NC state line and into southwest Virginia
may see precipitation begin as light sleet or freezing rain
tonight. The most likely areas to see a trace to a few hundredths
of an inch of ice before the changeover to rain will be in the
mountain communities near Laurel Creek, Forge Creek, and Brushy
Fork in eastern Johnson County, TN near the TN/NC line. Minimal
to no impacts are expected for most areas. As temperatures warm
within southerly flow, all areas in our forecast area are
expected to be predominantly a cold rain.

This system shifts east of the region by mid-morning Tuesday with
northerly flow and steady or falling temperatures during the day.
Some minor snow accumulation is possible across the higher
elevations of the East Tennessee and southwest Virginia mountains,
and perhaps some localized spots along the plateau near the TN/KY
state line. However, localized accumulation would likely only be
a dusting to one-half inch, and no impacts are expected.

Drier air arrives by Tuesday night. Patchy black ice could be
possible in areas that do not fully dry out, but the dry air and
wind should evaporate most moisture on surfaces. High pressure and
cooler air brings cool, clear conditions to the region on
Wednesday.

Chance probabilities of precipitation arrive by late week into the
weekend as a quick moving cold front and southerly low pressure
system approaches our area. Moisture is limited, but some
increased clouds on Thursday afternoon and Friday is expected. At
this time, this is most likely an all light rain event for most
locations. There is a chance for some wintry mix of rain and/or
snow across the higher terrain of the mountains. Details are
uncertain and forecast confidence in precipitation probabilities,
amounts, and types if fairly low on Friday into Saturday. There is
considerable uncertainty with whether these systems will remain
weak and separate or phase with a resultant stronger low pressure
system.

A quick moving northerly stream shortwave may impact the region on
Sunday or Monday, but details remain uncertain. At the very least,
minimal precipitation accumulation is expected with these likely
moisture-starved systems.

&&

.AVIATION...
(18Z TAFS)
Issued at 1123 AM EST Mon Dec 1 2025

VFR conditions this afternoon with lowering cigs during the
evening as moisture increases from south to north. MVFR conditions
deteriorate rapidly to IFR overnight across the region. Some LLWS
is possible during the overnight hours with light winds near the
surface and southerly 40 to 50 kt winds at about 5k ft.
Precipitation exits the region by the end of the forecast period
with gradually improving MVFR conditions by mid-day Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             42  45  27  50 / 100  40   0   0
Knoxville McGhee Tyson Airport, TN  40  44  26  47 / 100  70   0   0
Oak Ridge, TN                       38  43  25  46 / 100  60   0   0
Tri Cities Airport, TN              37  42  24  44 / 100  90   0   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...Wind Advisory from 11 PM this evening to 6 AM EST Tuesday for
     Blount Smoky Mountains-Cocke Smoky Mountains-Sevier Smoky
     Mountains-Southeast Carter-Southeast Greene-Unicoi.

VA...NONE.
&&

$$

DISCUSSION...JB
AVIATION...JB