A potent mountain wave event induced very strong non-thunderstorm wind gusts across southwest Virginia.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MRX wrote it up.
A potent mountain wave event induced very strong non-thunderstorm wind gusts across southwest Virginia.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Morristown, TN wrote its last area forecast discussion before the first event at Jan 12, 10:11 AM EST, 1 hour 49 minutes earlier.
Area Forecast Discussion
National Weather Service Morristown TN
1011 AM EST Fri Jan 12 2024
...New UPDATE...
.UPDATE...
Issued at 919 AM EST Fri Jan 12 2024
Sent a quick update to NDFD grids to account for downslope
conditions effects on temperatures this morning. Mountain wave
winds are already increasing with Cove Mountain gusting to 57 mph,
and Camp Creek gusting to 69 mph. These winds will only increase
in the coming hours as the low level jet increases in magnitude.
Upgraded to a high wind warning for Wise and Russell, VA where
there is higher confidence of higher wind gusts upwards of 60-65
mph.
Some areas across the valley such as Morristown, and the southern
valley are already seeing winds increasing with a recent
observation from CHA of 42 knots. These areas are seeing better
mixing already with less cloud cover. For those areas under cloud
cover, mixing will be delayed for a few more hours keeping winds
on the calmer side. Eventually these areas will see increasing
winds this afternoon.
Rainfall should be moving off the Plateau soon and will fill in
over the next few hours. There are steeper lapse rates just above
the inversion leading to some elevated CAPE. Already seeing a few
lightning strikes across Middle Tennessee, so wouldn't be
surprised to see a few lightning strikes in our areas as well.
Severe weather potential looks very low given the strength of the
inversion in place.
&&
.SHORT TERM...
(Today and tonight)
Issued at 300 AM EST Fri Jan 12 2024
Key Messages:
1. Strong southerly winds expected most of the daytime hours today
High Wind Warning for the far the eastern Tennessee Mountains and
Foothills. Wind Advisory in effect for the rest of east Tennessee,
southwest Virginia, and southwest North Carolina for today and
tonight.
2. Strong to severe showers and possibly a thunderstorm across
mainly the Plateau and southeast Tennessee for Friday afternoon.
Main concern is damaging winds.
3. Light snow showers or flurries possible for mainly the higher
elevations of southwest Virginia and northeast Tennessee tonight.
Discussion:
Currently seeing increasing clouds ahead of a strengthening low
pressure system expected to move up through the Ohio Valley towards
the Great Lakes. This will strengthen an impressive southerly low
level jet across much of the southeast US today. High Resolution
models remain consistent in 850mb winds increasing up to around 80
knots in the core of the jet as it moves through the Tennessee
Valley. These impressive winds will cause strong wind gusts area-
wide today. The highest winds are expected in the Southern
Appalachian Mountains and foothills today as the southerly to
southeasterly jet winds induce a strong mountain wave effect. In
many of the typical hard hit mountain wave locations we can expect
to see 60-90 mph winds. These winds will have enough momentum behind
them that they may continue down into the Valley and foothills of
the mountains. Based on HRRR, HREF and probabilistic guidance have
gone ahead and upgraded all of the counties along the Appalachian
Mountains to a High Wind Warning, with the possibilty of seeing wind
gusts up to 60 mph during the peak of the event today. Outside of
the mountains and foothills the remainder of the region is still
expected to see gusty winds today, with widespread 20-30 mph looking
likely, with gusts up to 40+ areawide. Cannot completely rule out
some isolated locations seeing 60 mph winds at some point today, but
most locations will see very strong advisory level winds.
In addition to the winds today there will be showers and possibly
thunderstorms moving through with this system. Currently the front
edge of the precipitation is across western Tennessee and will make
it to East Tennessee a few hours after sunrise. Isolated to
scattered showers will continue throughout much of the daylight
hours today. Once we get into the afternoon hours the lapse rates
above the low level inversion increase enough that a few hundred
J/kg of CAPE may be present in the atmosphere. This is enough to
warrant the mention of the possibility for occasional rumbles of
thunder, mainly across the central and southern Valley this
afternoon. Even if there is no thunder the rain showers could
enhance the downward momentum of the strong LLJ, bringing strong to
severe wind gusts at the surface...Maybe instead of severe
thunderstorms, we see more severe showers today.
This system will exit the area as fast as it moves in with the
majority of the precipitation moving east of the mountains around
00z. Rainfall totals today should remain below an inch areawide,
with generally less than half an inch north of Interstate 40. Some
orographic enhancement could cause some of the foothills over perform
compared to adjacent areas.
As we move into the overnight hours some lingering moisture could
get squeezed out of this system on the backside leading to light
drizzle or even some snow flurries across northeast Tennessee and
southwest Virginia overnight. If this does occur amounts should be
very light and little if any snow accumulation is expected.
&&
.LONG TERM...
(Saturday through Thursday)
Issued at 300 AM EST Fri Jan 12 2024
Key Messages:
1. Colder temperatures this weekend. But no significant weather
concerns.
2. Very cold temperatures early this next week, lows expected to be
in the single digits, and wind chills near or below 0 for Tuesday
night and Wednesday morning.
3. Likely accumulating snow on Monday/Tuesday with uncertainty in
amounts. Any small changes in QPF will result in large changes in
potential snowfall amounts.
4. Moderating, but still below normal, temperatures by late week.
Discussion:
In the wake of the departing cold front and associated strong
surface low over the Great Lakes, colder air will be in place on
Saturday. Clearing conditions are expected with some periods of
breezy weather on Saturday as westerly 850mb flow continues to be 30
to 40 kt.
On Sunday, the Arctic cold front will be moving southeastward across
the forecast area with CAA and below normal temperatures. The
shallow cold air may be slowed down some along the plateau, but it
is expected to move across the entire area by Sunday evening.
Clouds increase on Sunday night into Monday, and light precipitation
is forecast to overspread the region during the day on Monday. This
will be in response to divergence associated with a strengthening
300mb 140 kt upper jet across the Central Appalachians through the
Mid-Atlantic. Low-level convergent 850mb flow will increase and
overrun the cold air at the surface. GFS forecast soundings for
Monday show a saturated profile through the DGZ with temperatures
below freezing through the entire atmosphere. Surface temperatures
would likely be in the mid 20s while precipitation is falling which
would result in higher SLRs. Deterministic models and ensembles are
in good agreement with the setup for Monday. The big question is the
exact amounts of QPF. The ECMWF is showing closer to 0.1 inch, the
GFS is near 0.3 inch, and the GDPS is around 0.3 inch. With colder
temperatures resulting in higher SLR of 12:1 to 16:1 according to
the NBM on Monday afternoon through Tuesday morning, any small
changes in liquid QPF will create large changes to expected snow
totals. At this time, we will continue with around 0.2 inch QPF for
this system which is producing a mean of 2 to 3 inches of snow. The
NBM probabilities for 1 inch of snow in CHA is around 40 percent, at
both TYS and TRI the probability is around 70 percent.
As we head into Tuesday, bigger questions arise. The GFS and GDPS
are more progressive and negatively tilted with the approaching
shortwave and upper trough while the ECMWF is less progressive with
this shortwave and results in a weaker surface low. While the
deterministic ECMWF shows the weaker solution, many of its ensembles
continue to show a stronger system with higher QPF and potential
snow on Tuesday. For this reason, there is still a lot of
uncertainty on Tuesday about any potential wrap around moisture with
this southern low pressure system. With the stronger solution, we
likely get another 0.1 to 0.3 QPF, and with the weaker solution, we
get near nothing. The GFS ensembles are consistent with the stronger
solution which would keep precip, and snow, around through Tuesday
night, and perhaps Wednesday morning. These details won't be
resolved for several days.
The big story next week, besides the potential snow, is the very
cold temperatures. NAEFS data shows 850 mb temperatures near the 1st
percentile of climatology. The Arctic airmass, when combined with
potential snow cover, means very cold and much below normal
temperatures through the early to middle part of next week. There is
a decent chance that we will spend at least 72+ hours below freezing
for much of the area next week with temperatures in the teens and
single digits on Tuesday night into Wednesday morning. We start to
warmup above freezing on Thursday with temperatures remaining below
normal.
&&
.AVIATION...
(12Z TAFS)
Issued at 610 AM EST Fri Jan 12 2024
Aviation conditions will be dominated by a significant low level
jet expected to ramp up starting around sunrise and peaking during
the daytime hours with southerly winds in excess of 70 knots only
a couple of thousand feet off the surface. Low level wind shear
is expected to be strong throughout the daytime hours as the jet
remains overhead into the night time hours. High confidence that
there will be strong winds throughout the day today, but lower
confidence on exactly how many knots each airport will gust up to.
Scattered rain showers will move in during the day as well, and
for a brief period in the afternoon some embedded thunderstorms
looks likely, with some of the storms capable of producing winds
over 60mph at the surface. The winds will remain gusty overnight
with low ceilings moving in during the overnight hours and
continuing into Saturday morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 55 28 46 26 / 100 10 0 0
Knoxville McGhee Tyson Airport, TN 57 28 42 27 / 90 20 0 0
Oak Ridge, TN 54 27 43 24 / 100 20 0 0
Tri Cities Airport, TN 54 27 39 25 / 90 50 10 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Wind Advisory until 1 AM EST Saturday for Cherokee-Clay.
TN...Wind Advisory until 1 AM EST /midnight CST/ Saturday for Bledsoe-
Bradley-Hamilton-Loudon-Marion-McMinn-Meigs-Rhea-Roane-
Sequatchie.
Wind Advisory until 7 AM EST Saturday for Anderson-Campbell-
Claiborne-Grainger-Hamblen-Hancock-Hawkins-Jefferson-Knox-
Morgan-Scott TN-Sullivan-Union.
High Wind Warning until 7 AM EST Saturday for Blount Smoky
Mountains-Cocke Smoky Mountains-East Polk-Johnson-Sevier
Smoky Mountains-Southeast Carter-Southeast Greene-Southeast
Monroe-Unicoi.
High Wind Warning until 7 PM EST this evening for North Sevier-
Northwest Blount-Northwest Carter-Northwest Cocke-Northwest
Greene-Northwest Monroe-Washington TN-West Polk.
Wind Advisory from 7 PM this evening to 7 AM EST Saturday for
North Sevier-Northwest Blount-Northwest Carter-Northwest
Cocke-Northwest Greene-Washington TN.
Wind Advisory from 7 PM this evening to 1 AM EST Saturday for
Northwest Monroe-West Polk.
VA...Wind Advisory until 7 AM EST Saturday for Lee-Russell-Scott VA-
Washington VA-Wise.
&&
SHORT TERM...
LONG TERM....JB
AVIATION...Hazardous Weather Outlook National Weather Service Morristown TN 302 AM EST Fri Jan 12 2024 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-130815- Cherokee-Clay-Scott TN-Campbell-Claiborne-Hancock-Hawkins- Sullivan-Johnson-Morgan-Anderson-Union-Grainger-Hamblen- Northwest Cocke-Cocke Smoky Mountains-Northwest Greene- Southeast Greene-Washington TN-Unicoi-Northwest Carter- Southeast Carter-Roane-Loudon-Knox-Jefferson-Northwest Blount- Blount Smoky Mountains-North Sevier-Sevier Smoky Mountains- Sequatchie-Bledsoe-Rhea-Meigs-McMinn-Northwest Monroe- Southeast Monroe-Marion-Hamilton-Bradley-West Polk-East Polk-Lee- Wise-Scott VA-Russell-Washington VA- 302 AM EST Fri Jan 12 2024 /202 AM CST Fri Jan 12 2024/ This Hazardous Weather Outlook is for portions of southwest North Carolina...east Tennessee and southwest Virginia. .DAY ONE...Today and Tonight A strong system will affect the area today as a mountain wave event is expected across the east TN mountains and foothills. A High Wind Warning has been issued for these areas for this morning through tonight. A Wind Advisory has been issued for the rest of the eastern Tennessee Valley for today due to breezy conditions. Showers and possibly a thunderstorm are also expected, which could bring damaging winds to the surface, mainly across the Plateau and southeast Tennessee. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Early next week, expect very cold temperatures to move into the region with increasing potential of snowfall Monday to Tuesday. Tuesday to Wednesday, high temperatures are likely to stay below freezing with lows approaching single-digits, especially if snow is on the ground. Below zero wind chills are also increasingly possible. .SPOTTER INFORMATION STATEMENT... Spotter activation is not needed at this time.
Preliminary Local Storm Report
National Weather Service Morristown TN
900 AM EST Fri Jan 12 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM Non-Tstm Wnd Gst 3 ESE Wears Valley 35.70N 83.61W
01/12/2024 M57 MPH Sevier TN Park/Forest Srvc
Recorded at Cove Mountain Tower.
0600 AM Non-Tstm Wnd Gst 2 ENE Cades Cove 35.60N 83.78W
01/12/2024 M49 MPH Blount TN Park/Forest Srvc
Recorded at Cades Cove Wind Tower.
0545 AM Non-Tstm Wnd Gst 2 S Camp Creek 36.06N 82.77W
01/12/2024 M69 MPH Greene TN Mesonet
Recorded at the Camp Creek Elementary School
Wind Tower.
&&The national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
Several reports of trees being blown down by powerful non-thunderstorm wind gusts.
A 96 mph non-thunderstorm wind gust was recorded on a handheld Kestrel anemometer. Chaser also reported multiple trees were blown down on local roads.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2024Every state in 2024This day in weather historyWarnings in Virginia, January 2024
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1154613, 1154614.