From MRX and a stellar write-up over night w/ mountain wave discussion to boot....Never know, this might have been written by a contributor here.
National Weather Service Morristown TN
620 AM EST Thu Jan 22 2026
...New AVIATION...
.KEY MESSAGES...
Updated at 619 AM EST Thu Jan 22 2026
- One last day of warmer temperatures today with light
precipitation exiting to the southeast.
- Confidence in a significant winter storm affecting the southern
Appalachian region Saturday into Monday is increasing. However,
it must be stressed that details on where the axis of heaviest
precipitation and resulting wintry precip totals remain unclear.
There is also the possibility that some will see only rain or a
combination of rain and freezing rain. This weekend`s system
will need monitored closely.
- Cold air behind this weekend`s storm will keep temperatures
at/below freezing during the day with some very cold mornings.
This will prolong the effects of any winter weather, with power
outages possible as well.
&&
.DISCUSSION...
Issued at 1100 PM EST Wed Jan 21 2026
Discussion on the weekend system starts with the third paragraph.
A cold front lays to our west with light precipitation mostly
along the mountains now. Only a few hundredths of an inch, at
best, have been recorded across the forecast area last night.
This weaker system will exit the region around mid-morning today.
Today will also be the last day of 50s for highs across much of
the forecast area through possibly the rest of the month.
For tomorrow, northern parts of the forecast area will most
likely remain dry up until the strong weekend storm arrives. High
pressure tries to punch in on the backside with nearly zonal flow
aloft following the shortwave responsible for the Wednesday
system. It`s possible that whatever precipitation reaches into the
forecast area Friday, will mix with other forms of precipitation
type, especially across higher elevations. Surface temperatures
will be colder Friday. However, this is a window of warmer air
aloft trying to be replaced by colder air to the north.
Like it has been stressed for almost every new forecast run, we
just want to re-iterate that this forecast is very difficult and
has changed from run to run. Consensus still trends warmer, but
will get into that in a bit. On-set could be early or mid
Saturday, depending on many factors; models still vary on this. A
later arrival and peak of the event have trended out in time.
Sometime overnight Sunday or Monday morning is when the core of
the precip shield should be mostly to our east with some wrap
around possible on the back-side.
So, what is the set-up for this? Surface high pressure is expected
to dive down from western/central Canada. Compared to 24 hours
ago, it is close to 10 mb weaker from the strongest reading it
had in previous runs. Longwave troughing sinks south across the
country, meanwhile, a Baja upper low/closed low will eventually
eject eastward once it phases with the mean flow. Headed later
into Friday, a low center over the Four Corners region forms with
a couple of other low centers over northern Mexico region. A front
also arcs along the Gulf coast. Later Saturday an additional low
center forms near the FL Panhandle, as well as another off of the
Carolina coast. How the high pressure to our north and the Gulf
and Carolina lows interact, is pretty much the end all be all of
just what impacts we will see in regards to precipitation type.
The high and troughing will send in the colder air, however a
strengthening low to our south will send overrunning air out of
the southerly direction, or simply, much warmer air. Although
confidence has been severely low up until this point, the
confidence in higher snowfall amounts is surely lessening with
what seems to be a weaker surface high, therefore much warmer
temperatures at the surface, and signals for fairly strong
southerly low level winds. High wind potential or mountain wave
enhancement will need monitored especially during the Saturday
night time-frame. The NAM and RRFS runs show near 70 kts of
southerly low level flow. That would bring strong winds and gusts
to the mountains and foothills.
Overall, things could still change, BUT surface temperatures have
increased each forecast run for Saturday and Sunday highs, to be
precise. We just haven`t gotten into ranges or specifics on
snowfall totals, for example, because of just how much this
forecast has changed. Amounts were essentially slashed from
yesterday afternoon`s totals. I believe the increasing unknown or
challenge will be the question of freezing rain or rain and how
much. Storm total QPF range in the area of nearly 2 inches to
over 3 inches. In conclusion, the rain/snow line has shifted
north, therefore, snowfall amounts are decreasing from south to
north, with increasing chances of freezing rain and rain with each
new forecast run so far. Counties bordering Kentucky and West
Virginia are trending towards mostly snow with the greatest
amounts of the forecast area.
