Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/15/24
Area Forecast Discussion
National Weather Service Bismarck ND
919 PM CST Sun Jan 14 2024
.KEY MESSAGES...
- Life-threatening wind chills will continue across western and
central North Dakota through Monday morning. At least advisory
level wind chills (25 to 40 below) will continue through
Tuesday morning.
- Areas of blowing snow are likely late tonight through
Tuesday.
- Temperatures will moderate next week, with daytime highs
rising to above zero by Tuesday. A more significant warming
trend is looking probable by later next weekend into the
following week.
- On and off light snow west and south central Tuesday night
through Thursday.
&&
.UPDATE...
Issued at 919 PM CST Sun Jan 14 2024
Overall, the forecast remains in good shape. Air temperatures
have already fallen close to forecast lows in some parts of
western and central North Dakota, but the NBM temperature curve does
show a near-steady trend through the night. Even though
temperatures may not fall more than a few degrees further than
current observations, increasing winds overnight will once again
bring widespread wind chill values down into the 45 to 55 below
range.
.UPDATE...
Issued at 602 PM CST Sun Jan 14 2024
The forecast remains on track. Current observations and trends
were blended in for this update.
&&
.DISCUSSION...
Issued at 152 PM CST Sun Jan 14 2024
The ongoing Wind Chill Warning and potential for blowing and
drifting snow beginning late tonight are the main forecast
concerns today.
A wind chill warning remains in effect through tomorrow morning.
Most of the forecast area remains will within wind chill warning
criteria. A few areas have see winds drop enough that
technically they are in advisory criteria, but this will be
short lived as temperatures drop again this evening.
At the surface a 1048MB Arctic high is situated from Alberta
Canada into eastern Montana. A strong gradient remains from the
surface high and low pressure around the Hudson Bay. In the
upper levels the Hudson bay low and its associated surface low
will retrograde back to the west, increasing the surface
gradient winds over the Canadian Prairie Provinces into the
Northern Plains. A weak upper level trough drops south across
western ND tonight and may bring some increasing clouds, but the
main forecast issue tonight will be the increasing gradient
winds late tonight keeping our wind chills well within warning
criteria and increasing the potential for blowing and drifting
snow. With our last event, blowing snow was more of an issue
while we had falling snow and blowing snow occurring at the same
time. Tonight through Monday will only bring increasing winds
with little or no chances for snow. It`s also been greater than
24 hours since or snow and although it`s been quite cold,
increasing snow age will decrease the blowable snow.
Looking at the wind potential, Monday afternoon looks to be the
timeframe for highest winds. DESI winds show mean momentum
transfer monday afternoon around 30 knots with the max momentum
transfer around 40 knots. Bufkit RAP momentum transfer close to
this but just a but lower while Bufkit NAM/GFS momentum transfer
potential is around 3-5 knots less than DESI. On the high end
the DESI 90th percentile winds are only a couple knots higher
than the mean. So even though there are some winds higher up
approaching 50 knots, confidence is pretty high that with such a
strong inversion, they will not mix down. Therefore, at this
time it looks like near advisory criteria winds to a low end
wind advisory. As for the extent of blowing snow, as mentioned
earlier, without the falling snow, blowing snow reducing
visibilities substantially seems limited. There will be those
areas in open country that will be lower at times, but in
general, just talking about blowing snow, this seems to also
reach that near advisory to low advisory range. The wind chill
warning ends at noon CST Monday and we will likely need some
wind chill highlights to carry us through Tuesday morning. It`s
likely that this will be handled on the overnight shift. With
minimal wind and blowing snow hazards, it`s possible that one
Hazard (likely wind chills( could cover all three hazards.
That`s would be if nothing changes. If the wind potential and/or
blowing snow potential increases, we`d likely need a couple
products. Will pass this all along, but expect we will have at
least a wind chill hazard extended into Tuesday. And there is a
potential for wind/blowing snow hazards as well.
Tuesday night, we got rid of the NBM high bias and blended the
NBM with the NBMEXP and ConsShort. Winds jump back up on
Tuesday afternoon as well, but at this time winds Tuesday do not
look quite as strong as Monday, but there would likely still be
some patchy blowing snow.
Tuesday through Thursday some chances for snow enter the
forecast. Whether it`s with a shortwave rotating around the
Hudson Bay low, or a wave sliding into the west down a western
upper ridge, either should bring little in the way of
accumulating snows. The second setup does look to bring a better
chance of some light accumulating snows to the southwest
Wednesday night into Thursday. The NBM probability for an inch
or more of snow ending Thursday afternoon is currently greater
than 50 percent south and west of a line from roughly Beach to
Hettinger. At this time it appears maybe one more quick shot of
colder air, mostly far west on Friday, then a substantial warm-
up is looking more promising for next weekend with a quasi-zonal
flow developing.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 919 PM CST Sun Jan 14 2024
VFR conditions are likely through the forecast period. Northwest
winds around 10-15 kts this evening will slowly begin to increase
and become gusty later tonight through Monday morning, reaching 20-
25 kts with 30-35 kt gusts Monday afternoon. The stronger winds may
create areas of blowing snow, but confidence in visibility
restrictions is low.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Wind Chill Warning until noon CST /11 AM MST/ Monday for
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...Hollan
DISCUSSION...TWH
AVIATION...Hollan
Area Forecast Discussion
National Weather Service Dodge City KS
535 PM CST Sun Jan 14 2024
.KEY MESSAGES...
- Dangerously cold wind chills will continue through noon
Tuesday. A Wind Chill Warning remains in effect for the entire
DDC forecast area.
- Light snow flurries are possible Monday, although little to no
accumulations are expected.
- Another surge of cold air is forecast later this week,
beginning late Wednesday night/early Thursday morning and
persisting into the weekend.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 202 PM CST Sun Jan 14 2024
Water vapor satellite imagery and RAP upper air analysis at
midday indicates deep, longwave troughing encompasses the
entire CONUS, maintaining the arctic airmass that has been
entrenched across much of the central CONUS the past couple
days. This feature will inch ever-so slightly eastward through
the short term period, which unfortunately means the frigid
temperatures are not going anywhere with afternoon highs today
in the single digits. Surface high pressure will remain fixed in
place across the central plains tonight into Monday morning
fostering light winds, however with air temperatures sinking
well below 0F for much of the area, wind chills will still reach
the -10 to -30F range for all of southwest KS. As a result, the
Wind Chill Warning remains in effect for all counties through
the end of the short term period.
Daytime Monday, short range ensemble guidance suggests an upper
level shortwave trough embedded within the larger parent low
will dig southeastward from the northern Rockies into the
central plains, sending a reinforcing shot of cold air
equatorward along with a chance for some light snow flurries.
Little to no accumulations are expected given ensemble
probability of QPF greater than 0.1" sitting at 0% across all
zones, so there should be no impacts. Although, cold advection
via an uptick in northerly winds will support another day with
afternoon highs in the single digits.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 202 PM CST Sun Jan 14 2024
Monday night, northerly winds will gradually decrease as the
surface high pressure center moves into southwest KS following
the passage of the latest upper level shortwave trough. That
said, clearing skies will allow air temperatures to bottom out
into the 0 to -15F range by sunrise Tuesday, which will again
support morning wind chills in the -10 to -30F range. With full
sunshine daytime Tuesday and winds switching to southwesterly
on the northern periphery of surface high pressure, temperatures
will finally breach double digits by noon, and the multi-day
Wind Chill Warning will finally be allowed to expire. However,
we will have to wait one more day for temperatures to rise above
freezing as afternoon highs will range from the upper teens
north to upper 20s near the KS/OK border.
Southerly winds will continue into early Wednesday, but will
gradually abate as surface high pressure slides southeast into
Dixie Alley. As a result, a wide range of afternoon highs is
expected Wednesday with upper 20s across the northern zones
increasing to the mid 40s near the KS/OK border. Unfortunately,
these warm temperatures will not last, as medium range ensembles
agree cold air will once again surge equatorward, beginning late
Wednesday night/early Thursday morning and continuing through
the end of the long term period. Currently, this does not appear
to be true arctic air, but morning lows in the single digits
combined with at least modest northerly winds will still foster
wind chills well below zero. Therefore, more wind chill
headlines may be needed, especially Friday morning.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 532 PM CST Sun Jan 14 2024
Light and variable winds will continue as the arctic surface
high center will remain across Kansas through tonight into early
Monday. A band of light snow is expected to develop late in this
TAF period, possibly affecting HYS terminal, but will leave
mention of snow out of the TAF at this time. Ceilings are
expected to remain in the VFR category around 5000 feet.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Wind Chill Warning until noon CST /11 AM MST/ Tuesday for
KSZ030-031-043>046-061>066-074>081-084>090.
&&
$$
SHORT TERM...Springer
LONG TERM...Springer
AVIATION...Umscheid
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
543 PM CST Sun Jan 14 2024
.Discussion...
Issued at 303 PM CST SUN JAN 14 2024
Key Messages:
- Dangerous Wind Chills Continue
- Light Snow Far Southern Counties Late This Afternoon
- Light Snow Monday Afternoon Into Evening
Discussion:
H5 flow is currently zonal yet brisk around 80kts over the area.
Surface anticyclone still sits over the eastern Plains with surface
ridging extending toward the western Ohio River Valley. Strong and
deep inversion layer exists where there is some saturation which is
keeping the mid-level clouds around this afternoon. The lowest
levels are very dry for most of area, which has kept snow from
developing for the exception of isolated flurries. Our far southern
counties may pick up just a little bit more snow on the back end of
the vort max that is exiting the area, but recent radar trends show
the bulk of this activity has exited our area. The area is in for
another cold night, with wind chills dropping to -20 to -30 along
and north of Interstate 70 and between -15 and -20 southward. No
changes have been made to the wind chill headlines across the area.
Monday, another mid-level vort max moves through the flow with
stronger jet streak moving across the area. Deterministic solutions
depict this picking up low to mid-level moisture that will lower
cloud bases and help saturate the DGZ which is relatively close to
the surface. Convergence begins to increase by Monday afternoon
which will be capable of forcing snow showers across our area. 12z
HRRR this morning had an axis of QPF between 0.03 and 0.05 inches
mainly along I-70 but did expand north-south quite a bit, producing
snowfall between 0.5 and 1.0 inches. The 18z HRRR backed off a bit
on QPF though, keeping snowfall amounts maxing out at 0.5 inches.
HREF mean does not show much of signal for snowfall, but several of
the CAMs remain very dry. Model soundings do show some low-level
lift, however compared to few of the previous lighter and shorter
snowfall events, not seeing an overly strong signal for enhanced
FGEN or lower EPV within the zone of stronger convergence. Will
continue to monitor to see if kinematics come in more robust than
currently progged. Main concern will be is that light snow could
occur during the middle of the late afternoon and early evening
commute. Overall probabilities for QPF of 0.01 is around 50 to 60
percent but quickly drops off for threshold of 0.10 inches. As for
snowfall, probabilities for exceeding 1.0 inch of snow is less than
10 percent. Light snow, if it occurs, could stick to roadways
creating a few slick spots and may reduce visibility to around 1
mile.
For the remainder of the week, the bitter cold temperatures will be
the main story with highs struggling to climb above 0F and nightly
wind chills well below zero. Some relief starts to come Wednesday as
a short-wave over the Intermountain West promotes surface
cyclogenesis into the TX/OK Panhandle Region that turns low-level
flow southerly. The warming will be gradual, and overall
temperatures will still be below normal. However, it will be a
positive turn out of the dangerous temperatures we have been
experiencing. Toward the end of the week, this system likely brings
additional precipitation chances. Overall ensemble means look
relatively light with it, as the prior cold and dry will keep the
atmosphere deprived of robust moisture.
&&
.Climate...
Issued at 145 AM CST SUN JAN 14 2024
----------------------SUNDAY (1/14)----------------------
RECORD LOW FORECAST LOW
Kansas City (MCI): -10 (1979)** -14
KC Downtown: -5 (1979)** -12
St. Joseph: -16 (1979) -18
Kirksville: -16 (1979) -19
Sedalia: 2 (1997)** -11
RECORD COLD HIGH FORECAST HIGH
Kansas City (MCI): 0 (1979) -4
KC Downtown: 5 (1979) -1
St. Joseph: 0 (1979) -5
Kirksville: 9 (1972) -8
Sedalia: 18 (2005) -1
**Record low has already been broken for today (1/14/2024)
----------------------MONDAY (1/15)----------------------
RECORD LOW FORECAST LOW
Kansas City (MCI): -10 (1979) -11
KC Downtown: -9 (1972) -8
St. Joseph: -16 (1979) -16
Kirksville: -18 (1972) -16
Sedalia: -3 (2009) -8
RECORD COLD HIGH FORECAST HIGH
Kansas City (MCI): 6 (1972) 2
KC Downtown: 6 (1972) 4
St. Joseph: 4 (1972) 2
Kirksville: -3 (1972) -1
Sedalia: 12 (2009) 4
----------------------TUESDAY (1/16)----------------------
RECORD LOW FORECAST LOW
Kansas City (MCI): -13 (1977) -8
KC Downtown: -1 (2018) -4
St. Joseph: -12 (1977) -10
Kirksville: -9 (2009) -11
Sedalia: -3 (2018) -5
RECORD COLD HIGH FORECAST HIGH
Kansas City (MCI): 1 (1977) 12
KC Downtown: 9 (1982) 14
St. Joseph: -1 (1982) 11
Kirksville: 8 (1957) 6
Sedalia: 10 (2018) 13
&&
.Aviation...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 542 PM CST SUN JAN 14 2024
VFR conditions will prevail across the Kansas-Missouri state line
terminals overnight into early Monday afternoon. Expect MVFR CIGs
and VIS to start to spread across the region along with a chance
for snow Monday afternoon. Otherwise, Expect winds to remain from
the northwest through this TAF cycle.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...Wind Chill Warning until noon CST Tuesday for KSZ025-057-060-
102>105.
MO...Wind Chill Warning until noon CST Tuesday for MOZ001>008-011>017-
020>025-028>033-037>040-043>046-053-054.
&&
$$
Discussion...Krull
Aviation...Cutter
Climate...HB
Area Forecast Discussion
National Weather Service Indianapolis IN
849 PM EST Sun Jan 14 2024
.Key Messages...
- A Wind Chill Warning in effect across the northwest, Advisory to
the southeast through noon Monday.
- Temperatures will remain bitterly cold through Tuesday night,
with sub-zero wind chills.
- Light snow possible late Monday night; total snow accumulations
under 1 inch.
- Snow chances return Thursday into Friday.
&&
.Forecast Update...
Issued at 848 PM EST Sun Jan 14 2024
Upgraded the Wind Chill Advisory to a Wind Chill Warning across the
northwestern counties where satellite imagery is showing the cirrus
clouds quickly thinning out and temperatures have already begun to
drop lower than what was previously expected and below model
guidance.
The HRRR is much too aggressive with overnight lows falling well into
the negative teens across the area but that looks closer to reality
than most model guidance which have temperatures already at their
overnight lows with an 8-10 degree dew point depression over areas
with some snow on the ground. This combined with how ongoing
conditions are lining up with how conditions evolved last night
increases confidence high enough to warrant the headline upgrade.
There are a couple of alternate scenarios but both keep the marginal
wind chill warning conditions in place. The first would be if winds
turn closer to calm which would bring lower temperatures but similar
wind chills with the lower wind speeds. The other scenario would
see winds remaining in the 7-10 mph range which would keep
temperatures closer to -5 but wind chills near -25. Lowest wind
chills will be just after daybreak when winds look to increase by 1-
2 mph and before temperatures begin to rise. With it being a
holiday, impacts should be lessened by less people being out but
those heading outdoors should take proper precautions.
Additional adjustments to the headlines may be necessary if skies
clear further southeast but will be addressed as needed.
&&
.Short Term...(This evening through Monday)
Issued at 300 PM EST Sun Jan 14 2024
Surface analysis this afternoon is showing Arctic high pressure
from Alberta into the Tennessee and Ohio Valleys with a wound up low
over northern Quebec. Meanwhile, fast northwest flow aloft was
overhead with a deep trough over the Great Lakes and all but western
Canada. Meanwhile, Day Snow-Fog RGB visibility product and obs were
indicating increasing AC and cirrus approaching Missouri and
Illinois. Although, there were also a few sites with lingering
stratocu.
Wind chills earlier this morning made it as low as 31 degrees below
zero at a few spots north of I-70. However, the relaxing surface
pressure gradient has resulted in decreasing winds and wind chills
to drop below warning criteria.
Tonight...
Model layered RH progs and Hi-Res soundings support lingering mid
and high clouds tonight with the potential for clearing from
northwest to southeast toward daybreak. The increase in cloud cover
should keep temperatures from not getting quite as cold as they
did last night. That said, look for overnight lows in the negative
single digits over northwestern sections, where the clouds should
clear out. Conversely, with thicker clouds, south central sections
should mostly stay zero degrees or above.
Winds will drop off tonight as Arctic high pressure builds
in with a resultant weakened surface low pressure gradient. Even so,
wind chills should still drop into wind chill advisory
criteria (-15F to -24F) over most locales near and north of
Interstate 70 through Noon, So, plan on extended the Wind
Chill Advisory through Noon. Meanwhile, an SPS was issued for wind
chills from 3 to`14 degrees below zero south of the wind advisory.
Monday...
After a brutally cold start to the morning and increasing breaks in
the clouds per BUFKIT and layered RH progs, an upper wave will move
into the Missouri Valley as a 130kt jet streak rounds its base.
An increase in moisture and forcing should be enough to produce a
few late day snow showers and or flurries, mainly southwest.
Temperatures will be lucky to make it out of the single digits over
northwestern sections with Arctic high pressure lingering. That
said, weaker surface pressure gradient will lesson the impact of
wind.
&&
.Long Term...(Monday night through Sunday)
Issued at 300 PM EST Sun Jan 14 2024
The primary forecast challenge through the long range is continued
cold temperatures and occasional snow chances.
SYNOPTIC OVERVIEW
The Polar Jet currently resides over the CONUS, and is cyclonically
curved east of the Rockies. A large upper-level low pressure system
spins to our north across eastern Canada. Strongly negative NAO and
AO teleconnections promote a blocking pattern, which should keep the
upper low from moving out. As such, the current jet stream
configuration is expected to persist through the coming week.
Shortwaves embedded in the flow are to pass through at times this
week, with two in particular bringing snowfall chances. One passes
through Monday into Tuesday, and a more potent one passing by
Thursday into Friday. Surface high pressure situated mainly to our
west will limit potential for southerly return flow, so no major
warming trend is likely. A brief period of southwesterly winds ahead
of the Thursday wave is possible, which may increase available
moisture for precipitation.
Some signals exist in the day 8-14 period of a warming trend with
some active weather. A positively trending NAO/AO lends weight to
this scenario.
WEATHER HAZARDS AND IMPACTS
First and foremost, very cold temperatures are to continue this
week. And the prolonged nature of the cold may add stress to those
without the means to endure it. A brief "warm up" is possible
Wednesday into Thursday, ahead of the second shortwave, with highs
climbing into the upper 20s to low 30s. However, another surge of
arctic air is increasingly likely after the system passes by,
regardless of snowfall. Highs dropping back into the teens with
single digit lows, along with wind chills down to -20, are expected.
Regarding snowfall, two opportunities exist. As mentioned above, the
first is associated with wave arriving Monday. Total liquid QPF
appears very light, and only a few hundredths are anticipated.
However, with high snow ratios of near 20:1 up to an inch is
possible where the best forcing sets up. To avoid confusion, this
wave is distinct from the disturbance bringing snow this evening
south of our CWA.
The second opportunity for snow is Thursday into Friday. A large low
pressure currently spinning far out in the Pacific Ocean is the
feature of interest. It should lift northeastward into the Pacific
Northwest and become embedded in the polar jet, diving southeastward
until reaching Indiana. By this point it will be loosely organized,
and deprived of moisture...but still presents the potential for
accumulating snow.
FORECAST CONFIDENCE
NAEFS/ECMWF ensembles consistently show temperatures in the 10th
percentile or lower compared to climatological norms. GEFS spaghetti
plots show little variation in the mean 500mb heights through much
of the week. Additionally, teleconnections support continued
blocking and troughing through the week. As such, forecast
confidence is high regarding cold temperatures through the period.
Confidence is lower for snowfall, but increasing. Guidance has come
into more of an agreement for the Tuesday wave. Variance in guidance
remains for the Thursday wave, both in the run-to-run in individual
models and from model to model. Still, the majority of guidance
shows this system in some form or another.
&&
.Aviation...(00Z TAF Issuance)
Issued at 607 PM EST Sun Jan 14 2024
Impacts:
-Brief MVFR cigs through 08Z.
Discussion:
Generally VFR cigs expected through the early overnight hours, but
brief periods of cigs around 025 are expected. Highest confidence in
these lower cigs will be at LAF. Outside of that, VFR conditions
expected through the TAF period with westerly winds around 6-10kts
and scattered high clouds.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
Wind Chill Warning until noon EST Monday for INZ021-028>031-
035>038-043.
Wind Chill Advisory until noon EST Monday for INZ039>042-044>049-
051>057-060>065.
&&
$$
Update...White
Short Term...MK
Long Term...Eckhoff
Aviation...White
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
1008 PM EST Sun Jan 14 2024
...New UPDATE...
.UPDATE...
Issued at 944 PM EST Sun Jan 14 2024
A bit late on the evening update here, but wanted to have a little
bit to see some early time steps of the 00z guidance and see the
radar trends this evening as snow began to make it into our CWA.
Main changes to the forecast were to update the PoP grids to
reflect current radar trends and pretty strong onset of snowfall
pushing into our area over the next 4-6 hours. Have seen several
reports from Knoxville and points west that show snowfall
accumulating on surfaces already. Albeit light, the fact that it`s
already accumulating certainly lends confidence to the increase in
snowfall totals with the afternoon forecast package earlier today.
Current NBM hourly PoPs show this initial wave of precip moving
out around 09z, with a distinct lull thereafter through about
13-14z before the main show moves in after daybreak. This seems
very reasonable given the latest CAM guidance, but do not want to
try and time a 3-4hr lull in precipitation given that it won`t
have a significant impact on expected storm total amounts.
Another notable change was to include some sleet and freezing rain
precip types down in the Marion county area. NAM forecast
soundings for Huntsville this evening did indeed show a weak warm
nose through much of the overnight hours. Conceptually this would
extend further ENE into our CWA in the warm SWLY flow around
850mb in that region. We`ve had a report of a light glazing in
parts of eastern Marion county which confirms this thinking. Not
expecting this to last as the column will continue to cool and
precip rates increase. But it is in line with the uncertainty in
ptypes, and storm total accumulations for the southern valley and
far southeast Tennessee.
Lastly, WPC has upped the snowfall amounts for the event in the
I-40 corridor and points north. Didn`t want to make wholesale
changes to the forecast for the evening update, but this trend
doesn`t seem unreasonable given what`s already occurring this
evening. And it is worth noting that for the last few days, NBM
and HREF probabilistic guidance has been showing some healthy
probability of seeing storm total snowfall amounts easily
exceeding 8" across portions of the forecast area. Will let the
overnight shift make any substantive changes that are necessary
since they will have the full suite of the latest NBM
probabilistic guidance as well as the 00z models at their
disposal.
&&
.SHORT TERM...
(This evening through Monday Night)
Issued at 319 PM EST Sun Jan 14 2024
Key Messages:
1. Increasing confidence in a heavy snowfall, especially Knoxville
and north, exact placement of highest amounts will depend on where
exactly snow band sets up.
2. Potential still exists for a mix of precipitation types along the
Georgia border, lending to moderate uncertainty on snowfall totals
in the southernmost counties.
3. Precipitation late Monday night into Tuesday morning might switch
to a light freezing drizzle as snow comes to an end.
Discussion:
Mostly sunny skies across eastern Tennessee currently will give way
to the clouds associated with the incoming snowstorm. Expecting snow
showers to begin moving into the valley tonight, sometime between
00z and 06z for first showers. HRRR is a little quicker than the
HREF mean, but siding on the side of caution given how timing has
gone thus far. It seems likely at this point that snow will stick
as temperatures will be falling below freezing as snow arrives.
Therefore last preparations for snow should be completed this
afternoon and early evening. With the guidance continuing the
trend today to move the start time of snow showers up, elected to
begin the warning at 00z tonight, the winter weather advisory in
North Carolina will remain 06z.
Snowfall has increased with this package, now expecting a broad
spectrum of 6 to 8 inches along and north of Interstate 40, with
another maximum along the Cumberland Plateau. This forecast is
slightly under the WPC guidance, and it seems likely that some
locations will accumulate higher amounts. Placement of these
localized higher snowfall amounts is uncertain depending on exact
placement of narrow bands of higher snowfall rates. The other
uncertainty in snow amounts continues to be along the border
counties with Georgia, where a brief mix of sleet seems probable
given the persistence in the high resolution guidance. For
temperatures tomorrow, stuck with persistence with the prior
shift. Some guidance, and the NBM, is warmer with the max
temperature, but it`s hard to reconcile that idea when no strong
advection is in place to power that warmth against the chilling
effect of ongoing snowfall.
Snow starts out tonight as generally scattered, and guidance has
indicated a lessening or pause before becoming more steady
stratiform snow with embedded bands during the daytime on Monday.
While the HREF doesn`t suggest any 1"/hr rates, steady snowfall will
lead to higher accumulations as Monday wears on. This translates
to road conditions steadily worsening, especially secondaries and
lesser frequented roads, as the day wears on. Monday night into
early Tuesday might feature light freezing drizzle on the backside
of the snow as moisture in the atmosphere lowers beneath the DGZ
and thus only supercooled water will fall. Ice accumulations with
this is expected to be a glaze at most.
&&
.LONG TERM...
(Tuesday through next Sunday)
Issued at 319 PM EST Sun Jan 14 2024
Key Messages:
1. Very cold temperatures in the wake of the snow that will tape off Tuesday
morning. Single digit/ near zero temperatures and subzero wind chills
possible Tuesday night into Wednesday morning.
2. Additional winter system possible Thursday night into Friday, but
details still uncertain. Ensembles are in not in the best agreement
with the system, but there is high confidence in cold weather behind
this system lasting through the weekend.
Discussion:
As drier air will begin to move in late Monday night into Tuesday
morning the main areas of precipitation will begin to exit the area
as the upper level energy shifts northeast. At the end of the
precipitation there is a possibility of some light freezing drizzle
or flurries before tapering off Tuesday morning. Any ice
accumulation should be minor with the snowfall being the main
impact. Very cold air then advects into the area Tuesday. High
temperatures Tuesday with the Arctic airmass high pressure will be
in the 20s with wind chill readings in the teens as winds will be
about 10 mph. With the high pressure area directly overhead Tuesday
night and early Wednesday winds decrease and temperatures will
plummet to single digits areawide. Wind chill temperatures Wednesday
night and early Thursday will be between zero and 10 below.
Wednesday night and Thursday the Arctic high pressure will shift
eastward and this allows winds to shift to the south and southwest
Wednesday afternoon and overnight. Temperatures warm about 10
degrees Wednesday night and another 10 degrees Thursday with most
locations in the 30s to around 40. However with anticipated snowfall
by Tuesday temperatures may stay below freezing in some areas.
The next weather change will be Thursday into Friday as a low
pressure area develops across the southern plains and with
increasing moisture will bring a fast moving front through the
forecast area Friday. The track of the low is expected to go south
of the region at this time. With the short period of southerly flow
and the uncertainty with warming based on entrenched cold air with
the Monday/Tuesday system expect precipitation amounts to not be
that high. If temperatures are in the mid 30s to around 40 at onset
of the precipitation Thursday afternoon like models are showing
there should be mixed precipitation with rain and snow. The mixed
precipitation should continue into the evening. Then the rain should
change to snow and become all snow by Friday. The amount of warming
and the moisture available will affect snowfall amounts. This is
still uncertain. The precipitation is moving out Friday night.
Behind the system Friday there is still a higher confidence of more
cold temperatures with Arctic High pressure building in Friday night
through Sunday. Lows again look to be in the single digits Saturday
and Sunday mornings. Highs once again in the 20s Saturday and then
warming into the 30s Sunday as the large surface high shifts east of
the Appalachians by late in the day.
&&
.AVIATION...
(00Z TAFS)
Issued at 651 PM EST Sun Jan 14 2024
Currently have VFR conditions across eastern TN this evening, but
this will change as snowfall begins to move in from the west.
Should see flight categories fall pretty uniformly at all sites,
into IFR or LIFR territory overnight. The band of heaviest
precipitation and snowfall should be situated INVOF KTYS closer to
daybreak so went with some moderate snowfall there with VSBY of
less than 1SM. Doubt there will be much of any improvements after
12z so the TAFs are pretty short in that regard.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 45 28 34 20 / 10 40 80 60
Knoxville McGhee Tyson Airport, TN 43 25 31 22 / 0 50 100 80
Oak Ridge, TN 41 24 30 19 / 0 60 100 80
Tri Cities Airport, TN 44 24 32 24 / 0 50 90 80
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Winter Weather Advisory from 1 AM Monday to 7 AM EST Tuesday for
Cherokee-Clay.
TN...Winter Storm Warning until 7 AM EST /6 AM CST/ Tuesday 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...Winter Storm Warning until 7 AM EST Tuesday for Lee-Russell-
Scott VA-Washington VA-Wise.
&&
$$
SHORT TERM...CD
LONG TERM....TD
AVIATION...CD
Area Forecast Discussion
National Weather Service Nashville TN
812 PM CST Sun Jan 14 2024
...New UPDATE...
.UPDATE...
Issued at 755 PM CST Sun Jan 14 2024
It`s snowing!!! All of our observation sites are reporting snow
this hour with the heaviest falling along and south of I-40. We`ve
already received a report of 0.5" of snow in Bellevue. Looking at
the latest run of the HRRR tonight, boy did it come in hot. It
paints a narrow band of higher totals ranging from 6-8 inches from
Wayne County all the way through to our furthest NE counties on
the Plateau, including Nashville. This solution would mean this
event overachieves a little further north than originally
forecasted and it pumps out more snow in any heavier bands that
move through. This will be something to watch as the night
progresses. There were talks of bumping up QPF along our northern
border to match up with this latest run of the HRRR, but for now,
we`re going to hold off on that to see what the next round of
models show since this is only 1 run. Our sounding tonight shows a
textbook snow event; big, healthy layer of moisture right in the
snow growth region with all layers below 0 degrees Celsius. As for
temperatures, they have tanked. Most everyone is sitting right
around 20 degrees and dropping. We will be back with a full
forecast update in the next several hours. In the meantime, stay
safe, stay warm, and enjoy the snow!
&&
.SHORT TERM...
(This afternoon through Monday Night)
Issued at 130 PM CST Sun Jan 14 2024
No major changes will be made to the forecast for the very cold
and snowy weather coming our way. A Winter Storm Warning remains
in place area-wide from 6 PM today until 6 am Tuesday.
Snow was already crossing the Ms River early this afternoon.
Short range models show the snow spreading rapidly eastward into
our area late this afternoon and evening. Snowflakes should start
to fall in our western counties by 4 or 5 PM. By midnight, the
ground will likely be covered for most areas along and west of
I-65 with an inch of fresh powder, and up to 2 inches for some
spots. By daybreak Monday, much of the Mid State will have snow
cover, averaging 1 to 3 inches. Then, the second main wave will
move across the area late Monday morning through afternoon with
the greatest additional accumulations focused along a band from
Waynesboro and Lawrenceburg northeast to Crossville and Jamestown.
Models have become as agreeable and consistent as we can hope for
with winter wx in our region. We are still expecting all snow with event
totals averaging 1 to 3 inches over our northwest counties and 4
to 7 inches across our southern and Plateau counties. Areas around
Clarksville could come up a little short, especially with the
second wave tomorrow falling mostly south of I-40. Some spots in
the main band across the south and Plateau could over-achieve with
7-8 inches under locally enhanced bands. Nashville Metro is on the
edge of the higher band, so a small shift in this band could raise
or lower totals for Metro.
The snow will taper off Monday night as temperatures plunge
further. Lows by Tuesday morning will be around 10 degrees with
wind chills down in the single digits below zero for much of the
area. A wind Chill Advisory will likely be needed, but we will
wait til later tonight or Monday before focusing more on the cold.
&&
.LONG TERM...
(Tuesday through next Sunday)
Issued at 130 PM CST Sun Jan 14 2024
After the snow leaves, bitterly cold, dry air will grip the Mid
State Tuesday through Wednesday. A fresh blanket of snow will
enhance the cold temperatures. Highs will be limited to the teens
for many areas on Tuesday and down near zero Tuesday night. The
snow on the ground will not go anywhere through midweek with these
frigid, yet not record-setting temperatures.
Temps will finally climb above freezing Thursday just before
another system comes our way with another chance for snow and
another blast of Arctic cold air. Latest models show potential
for up to an inch of snow with this fast moving system late
Thursday through Friday followed by more bitter cold and dry air
for the weekend.
&&
.AVIATION...
(00Z TAFS)
Issued at 529 PM CST Sun Jan 14 2024
Snow will impact the terminals over the next 24 hours. Light snow
will start over the next couple of hours at all the terminals and
continue through the overnight hours and on Monday. Visibilities
will bounce between MVFR/IFR depending on the intensity of the
snow. There will be brief periods of LIFR visibilities but timing
cannot be pinned down. Cigs will deteriorate to MVFR this evening
and decrease to IFR at CSV and SRB Monday morning. Winds will be
out of the north between 5-10 kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 16 22 11 21 / 80 80 50 0
Clarksville 11 19 6 17 / 70 50 30 0
Crossville 17 26 10 18 / 80 90 100 0
Columbia 14 22 11 20 / 80 90 50 0
Cookeville 16 23 11 17 / 80 90 90 0
Jamestown 15 23 12 17 / 80 80 100 0
Lawrenceburg 16 23 10 19 / 80 90 60 0
Murfreesboro 15 24 6 20 / 90 90 70 0
Waverly 10 20 7 18 / 80 70 30 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 6 AM CST Tuesday for Bedford-Cannon-
Cheatham-Clay-Coffee-Cumberland-Davidson-De Kalb-Dickson-
Fentress-Giles-Grundy-Hickman-Houston-Humphreys-Jackson-Lawrence-
Lewis-Macon-Marshall-Maury-Montgomery-Overton-Perry-Pickett-
Putnam-Robertson-Rutherford-Smith-Stewart-Sumner-Trousdale-Van
Buren-Warren-Wayne-White-Williamson-Wilson.
&&
$$
UPDATE.......Baggett
SHORT TERM...13
LONG TERM....13
AVIATION.....Reagan
Area Forecast Discussion
National Weather Service Paducah KY
642 PM CST Sun Jan 14 2024
.KEY MESSAGES...
- Accumulating snows incoming later today through tonight, into
Monday. The best chance for accumulating snows are across much
of western Kentucky, southeast Missouri, and far southern
Illinois, where 1 to 2 inches is broadly forecast and an
Advisory is in effect. Up to 3 inches is possible closer to
the Arkansas and Tennessee borders. Lesser amounts are
forecast north of Route 13 in southern Illinois and for
southwest Indiana.
- Arctic cold air temperatures, with wind chills in the negative
digits, are forecast each night this week except for Wednesday
night. A reinforcing blast of Arctic air comes later Thursday
into Thursday night, and it too may bring potential for light
accumulating snowfall.
&&
.UPDATE...
Issued at 642 PM CST Sun Jan 14 2024
Updated the forecast to expand the Winter Weather Advisory
northward into Union, Henderson, and Daviess Counties in
northwest Kentucky, where reports of snow accumulation resulting
in accidents have been relayed. Given radar trends with heavier
snow still ongoing in that area, we felt it prudent to expand
the advisory to include the Henderson and Owensboro areas. Also
adjusted temperatures tonight based on current observations,
which results in slightly lower lows tonight and lower highs on
Monday.
Otherwise, the remainder of the forecast is unchanged from the
previous forecast. Generally 1 to 2 inches is expected in the
advisory area, with lesser totals to the north and somewhat
higher totals near 3 inches possible in far southern sections of
the area. Most of this accumulation occurs this evening, with
just minor additional accumulation possible overnight and into
Monday.
&&
.DISCUSSION...
Issued at 115 PM CST Sun Jan 14 2024
Kuchera method applied to the GFS and Canadian deterministic 12Z
runs indicate the Advisory is well placed with a 1-2" swath across
its heart. Higher totals closer to 3" are possible near the AR/TN
borders, with lesser amounts anticipated along/north of the northern
tier of Advisory counties. The latest HRRR supports our forecast
totals with its liquid equivalent QPF, esp across our southern-
most counties in the Advisory. With LSR`s running closer to 15:1
south to near 20:1 north, it won`t take much to squeeze out
some accumulations from even negligible qpf. WPC`s new QPF
forecast keeps us in up to a tenth inch range for the days 1-2.
Will leave the Advisory as drawn, adding a couple western Ky
counties per collaboration, as the WSSI offers "minor impacts"
support broadly across it as drawn. Real-time camera shots out
of Joplin, MO show the ground started whitening within a half
hour or so of the snow starting, and that was still with about
an 8 degree TDD at that time.
Incoming timing looks the same. The GFS/Canadian may be a
little quicker with its accumulations, late this afternoon...but
looking upstream at real time...it does have to saturate down
to get that...think it`ll be quick to do so just like upstream,
but don`t know if that quick. Nevertheless, the evening into
overnight/Monday still looks good prime times for accumulating
potential...so no real changes there either. Soundings suggest
precipitating to ground/beginning at least in our western
counties after 21Z regardless, and maybe pushing east of the
MS river even by/before 24Z.
Back end timing may be/become problematic. Deterministic
modeling is downplaying the Monday chance a little, while
ensemble/means continue it, but mainly east of the MS River.
This was anticipated in our original issuance, so we`ll leave it
as is now and let the event play and then cancel or expire as
needed, where needed, as it unfolds.
The heart of the coldest air lends some wind chill concerns for
Monday and Tuesday nights. We`ll be in the negative numbers across
the FA with the north poised for another potential headline
around/below -10. Effective snow cover will impact low temps, which
will impact resultant wind chills...so we`ll highlight them within
our broader messages but hold off on any headlines for this package.
After a brief moderation Thursday, still below normal highs but at
least getting above freezing for the first time...we keep getting a
strong/consistent signal for another blast of Arctic air to finish
the week. We`re looking at highs right back in the 20s, maybe even
teens north, with single digits lows and negative wind chills again
to end the week.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 547 PM CST Sun Jan 14 2024
Light snow, accompanied by MVFR cigs and IFR vsbys, are moving
across the southern two-thirds of the Quad State this evening.
Around an inch or two of snow is possible. Further north,
skies are also overcast but are VFR. Winds are northerly at 5-8
kts and will remain as such through the TAF period. Snow moves
out later tonight, with low end precip chances continuing for
the remainder of the TAF period, mainly for Western Kentucky.
Cigs lift to VFR later tonight, continuing for much of tomorrow
with MVFR cigs potentially returning to southern areas late in
the TAF period.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...Winter Weather Advisory until 6 PM CST Monday for ILZ088>094.
MO...Winter Weather Advisory until 6 PM CST Monday for MOZ086-087-
100-107>112-114.
IN...None.
KY...Winter Weather Advisory until 6 PM CST Monday for KYZ001>022.
&&
$$
UPDATE...RJP
AVIATION...ATL
Area Forecast Discussion
National Weather Service Phoenix AZ
440 PM MST Sun Jan 14 2024
.UPDATE...
00Z Aviation Discussion.
&&
.SYNOPSIS...
Dry conditions will persist the next several days across the
Desert Southwest under clear to mostly clear skies. Temperatures
will continue to warm up throughout the week, starting out near
normal through Tuesday before peaking late week at seven to ten
degrees above normal. High temperatures are forecast to top 70
degrees across all of the lower deserts by Thursday with some
locations even seeing the middle seventies for Friday and
Saturday. Rain chances will increase next Sunday as a Pacific low
pressure system affects the region.
&&
.DISCUSSION...
Latest water vapor imagery and RAP streamline analysis reveal a
weak short-wave trough moving eastward through southern NV. This
system is producing little in the way of cloudiness across the
Desert Southwest. However, this trough combined with the influence
of another system diving southward into the eastern Rockies
Monday will keep height rises associated with a West Coast ridge
at bay. Net result will be little change in thicknesses Monday,
and consequently slightly below normal temperatures will persist
one more day.
A return to above normal temperatures is anticipated Tuesday as
the aforementioned ridge migrates eastward but also weakens across
the Rockies. Temperatures will only increase slightly Wednesday
as a storm system affects mainly the Pacific Northwest and
northern Rockies. This will be followed by a more substantial
warming trend through the end of the week as an amplified ridge
moves eastward through the intermountain West. Latest NBM suggests
high temperatures across the lower Deserts will reach the mid
70s, which would be the warmest readings since late December.
Model ensembles are in good agreement an eastern Pacific trough
will bring increasing moisture, considerable cloudiness and
somewhat cooler conditions Saturday. Rain chances increase Sunday,
but the details remain murky given the inherent timing and
intensity uncertainties. Latest NBM indicates roughly a 20-40
percent chance of measurable rain Sunday night across Arizona, but
this will likely change over the coming days.
&&
.AVIATION...Updated at 2340Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT;
Southeast California/Southwest Arizona including KIPL and KBLH:
VFR conditions with no aviation weather concerns are anticipated
through the forecast period. Skies will begin mostly clear this
evening, however high clouds will increase in coverage overnight
and throughout the day tomorrow. Winds will remain light (aob 7
kts) and follow diurnal trends, although there will likely be
extended periods of variability.
&&
.FIRE WEATHER...
Dry and tranquil conditions will prevail this week under clear to
mostly clear skies. A slow but consistent warming trend will
eventually push temperatures to above normal by the latter half
of the week. Expect little change with moisture levels this week
with daily MinRHs mainly falling to 20-30% each day across the
lower deserts to 30-35% in higher terrain areas. Light winds will
also prevail at least through the next several days following a
typical diurnal directional pattern.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Hirsch
AVIATION...Salerno
FIRE WEATHER...Kuhlman