Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/15/25
Area Forecast Discussion
National Weather Service La Crosse WI
957 PM CST Fri Feb 14 2025
.KEY MESSAGES...
- Snow this afternoon into Saturday morning. The evening
commute will be impacted by snow covered roadways. Snow rates
of up to 1 inch per hour will be possible during the afternoon
and evening.
- Another band of snow sets up over the area for the overnight.
There is still a little uncertainty on where exactly the band
sets up. Current forecast has this band setting up around and
south of I-90. Light snow will then continue during Saturday
afternoon. Snowfall totals are between 3 and 6 inches with the
highest amounts mostly in southwestern Wisconsin around the
I-90 corridor. With these totals, a Winter Weather Advisory
has been issued for the entire forecast area.
- Dangerously cold temperatures are still on track for next week
with wind chills of 25 to 40 below in the mornings from Monday
to Thursday.
&&
.UPDATE...
Issued at 957 PM CST Fri Feb 14 2025
The first round of snow has generally exited the region this
evening leaving behind amounts of 1 to 3 inches in its wake
across the area. As we head into the overnight, noting some
transient pieces of frontogenesis in the recent RAP. One of
these bands can be noted over portions of northern IA where Fort
Dodge, IA recently started reporting snow. As we continue over
the next few hours, thinking that some banded snow will develop
over the region. However, confidence remains low in exactly
where any particular band will set up overnight. By sunrise,
the RAP and much of the CAMs continue to suggest a better mid-
level frontogenesis signal that instigates a slightly more
broad precipitation shield near and south of Interstate 90 that
continues through the morning and diminishes over the afternoon.
Within the 15.00z HREF there remains fairly high probabilities
(50-80%) for over an inch of snow south of a Rochester, MN to
Black River Falls, WI line with a sharp cutoff north. There are
some low-end probabilities (10-20%) for additional amounts of
4-6" in the 15.00z HREF. However, this would likely be very
localized and contingent on how any banding ultimately sets up.
As a result, have held onto the advisory for now but will likely
need to make some adjustments to both timing and areal extent
as model and observational trends reach a better consensus
overnight.
&&
.DISCUSSION...
Issued at 249 PM CST Fri Feb 14 2025
Today-Early Saturday Morning: Impactful Snow Expected, Heavy At Times
A shortwave continues to make its way across the Central Plains and
into the Upper Midwest. Strong southerly flow continues to bring
moisture northward into the area. This moisture transport along with
the lift will help to bring snow northward. Strong 700mb
frontogenesis oriented northwest to southeast moves through the
forecast area during the afternoon and evening. Snow rates with this
first burst could approach 1 inch per hour. While this first band of
snow will not last long, 4 to 5 hours at any location, the snow
rates will impact the evening commute as snow covered roadways are
expected. This band looks to bring a quick 1 to 3 inches for
southeastern Minnesota and northeastern Iowa with 2 to 4 inches for
western Wisconsin. One last thing to mention for today is that with
stronger winds, wind gusts between 25 and 35 mph, in Iowa and
southeast Minnesota, blowing snow could be a problem.
After midnight another band of snow sets up over the area as more
shortwave energy mixes with good frontogenesis. This band would
gradually shift southward during the morning, however there is still
quite a bit of uncertainty as to where this band sets up due to how
narrow of a band it is. CAMs have this band setting up anywhere from
I-90 to just clipping our southern counties. Snow to liquid ratios
through Saturday morning are roughly 12:1 to 15:1. This band of snow
could produce another 1 to 3 inches bringing totals closer to a 6 to
8 inch range where the band sets up at.
Saturday: Additional Snow
More snow is expected for Saturday as frontogenesis Saturday
morning is good, especially for areas along and south of I-90.
This area will also be under the left exit region of a jet
streak. So there will be ample lift across the area. With these
ingredients in mind, more deformation snow banding will continue
across this area. Due to how narrow this banding will be, the
exact location of these snow bands will continue to fluctuate.
The latest runs of CAMS continue to position these bands as far
north as I-90 to just clipping Clayton and Grant counties.
Additionally, some of the CAMS show periodic southwest to
northeast oriented snow bands pushing across northeast Iowa and
southwest Wisconsin during the day. Based on where the strongest
areas of lift are, the expected place for these bands is across
portions of northeastern Iowa and southwestern Wisconsin.
Compared to where todays heaviest snow is likely to fall,
Saturday`s snow will likely be south of that area. Snow ratios
for the snow tomorrow will start around 12:1 to 15:1 and then by
the end of the day transition to 15:1 to 18:1.with all this
being said, snow totals for Saturday across the forecast will
mostly range from 1 to 3 inches with the highest values
occurring where this snow band sets up. Currently the highest
forecasted snow amounts are for portions of northeast Iowa and
southwestern Wisconsin. While there are some discrepancies where
the snow bands sets up, due to our proximity from the surface
low, these totals are not expected to grow unless the low track
changes and shifts further north.
Sunday-Thursday: Dangerously Cold
After the snow moves out of the area, the longwave trough sets up
over the Northern Plains and Upper Midwest for the rest of the week
giving way to very cold arctic air sitting over the area. This can
be seen by looking at the 850mb temperatures, which are roughly
between -25 and -20C, with the coldest air setting up on Monday
night into Tuesday. EFI values are between -0.9 and -0.6 with some
areas of southeast Minnesota and northeast Iowa showing values down
to -0.95 for Tuesdays high temperature. NAEFS anomalies continue to
range from -3.5 to -2.5. With both the EFI and NAEFS values so low,
they are leaning towards some of the lowest temperatures that have
occurred during the climatological period. High temperatures
are forecasted to be in the single digits and teens while low
temperatures are in the single digits and teens below zero. Wind
chill values for Monday and Tuesday mornings are currently
ranging between 25 and 40 degrees below zero. For Wednesday and
Thursday mornings the wind chill readings are currently
forecasted to be -20 to -30 degrees below zero.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 549 PM CST Fri Feb 14 2025
A fairly tricky forecast remains over the next 24 hours with
various periods of snow resulting in IFR conditions across the
area at times. Currently, a band of heavy snow is quickly
shifting east of the area with visibilities notably improving at
both KRST and KLSE over the past hour. This is expected to
continue as the back edge of the snow works its way into KRST
between 00z and 01z and later for KLSE. As we head into the late
evening and overnight, the current HREF suggests fairly
respectable probabilities (40-60%) for at least MVFR cigs but
cannot rule out some patchy low-VFR or IFR as well (20-30% for
both in the HREF). Attention then turns to a secondary band of
snow that will form near the MN border as shown in the recent
CAMs around or just before midnight. Currently, the CAMs keep
areas from I-90 and north free of snow through much of the
overnight. However, the CAMs agree on developing the band
further north into both KLSE and KRST prior to daybreak with
MVFR to IFR visibilities likely (70-90%) at times. Confidence
remains on the lower end for how long snow would last at KRST as
the CAMs keep the Rochester area on the northern edge of the
precipitation shield. Regardless, the band will shift southeast
through the afternoon allowing for visibilities to improve but
cigs will remain at MVFR to IFR levels through 00z Sunday.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory until 6 PM CST Saturday for WIZ041>044-
053>055-061.
Winter Weather Advisory until 6 AM CST Saturday for WIZ017-029-
032>034.
MN...Winter Weather Advisory until 6 PM CST Saturday for MNZ094>096.
Winter Weather Advisory until 6 AM CST Saturday for MNZ079-
086>088.
IA...Winter Weather Advisory until 6 PM CST Saturday for IAZ008>011-
018-019-029-030.
&&
$$
UPDATE...Naylor
DISCUSSION...Cecava
AVIATION...Naylor
Area Forecast Discussion
National Weather Service Denver/Boulder CO
820 PM MST Fri Feb 14 2025
.KEY MESSAGES...
- Ongoing mountain snow will continue to produce impacts across
the higher elevations through Saturday evening.
- Rain and snow diminish by midnight across the plains. Dense fog
may occur late tonight thru mid morning on Saturday along
portions of the I-25 Corridor and Palmer Divide (30% Confidence).
- Rain and Snow redevelops across northeast Colorado Saturday
afternoon.
- Active pattern continues into next week, with the best chance
of snow Monday into Tuesday.
- Very cold air returns to northeast Colorado for Tuesday and
Wednesday.
&&
.UPDATE...
Issued at 816 PM MST Fri Feb 14 2025
Satellite imagery shows a mid level circulation over east central CO
which is moving southeast. Widespread rain and snow is occurring to
the north of this feature over nern CO. As the system contnues to
move southeast, the precip should gradually end from north to
south by midnight. Over the mtns, mainly light snow will continue
overnight, however, towards 12z moisture depth will increase which
should allow for steadier snow of varying intensities thru Sat
aftn.
Finally, hi res data has been showing areas of dense fog late
tonight thru mid morning on Sat, over portions of nern CO. Most
of this is focused along the I-25 Corridor and Palmer Divide.
Overall confidence isn`t real high, as low and mid level cloud
cover may impede it`s development, so have refrained from issuing
a Dense Fog Advisory at this point.
&&
.SHORT TERM /Through Saturday/...
Issued at 211 PM MST Fri Feb 14 2025
Northeastern Colorado continues to be a humbling place to
forecast. Temperatures briefly warmed into the mid/upper 50s
across the metro (58F at KDEN), while many locations in the plains
to the north never quite got into the warmer temperatures before a
weak cold front spilled in. Now the question turns to what type of
precipitation (and how much) falls this evening and early tonight.
Guidance was too slow on the frontal passage, and there`s already
a few convective showers across the southern portions of the CWA.
RAP Mesoanalysis has 250-500 J/kg of MUCAPE across Lincoln county,
and it wouldn`t be shocking to see a weak thunderstorm or two
develop south of I-70 later this evening as moisture deepens. It`s
also unclear how quickly temperatures will fall this evening, with
most solutions favoring mostly rain. However, a slushy inch or two
of snow is possible east of the metro this evening if we can get
heavy enough precipitation rates to overcome to marginal thermal
profile.
Meanwhile, mountain snow continues this afternoon, with one main
organized band of snow from Montrose into the Vail Pass area
pushing east. We expect snow rates to diminish a bit overnight,
as the upper trough axis moves across the state and we start to
see QG subsidence take over. There will still be light to moderate
snow across the higher terrain with favorable orographic lift, but
impacts may diminish a bit across the mountain valleys as we get
towards Saturday morning. The flow aloft will increase and shift
to the northwest for the second half of the day, and snow should
become more widespread across the I-70 and northern mountains.
Gusty winds should also bring more widespread blowing snow,
leading to difficult travel across the mountain passes during the
afternoon and evening. Moisture quickly diminishes after sunset
with snow tapering off overnight.
The forecast for the plains doesn`t get much easier tomorrow.
Most deterministic guidance continues to slowly advect in
cooler/moist air into the region through the overnight. BUFKIT
soundings from a variety of models all support a period of dense
fog across the I-25 corridor and adjacent plains in the morning
hours, though there is quite a spread in timing/intensity of the
fog. Either way, a combination of fog, mist and/or stratus will
likely welcome you to the weekend, along with much cooler
temperatures. We`ll likely struggle to break into the low 30s
during the day with persistent low cloud cover. As an upper jet
approaches, there is increasing potential for afternoon snow
showers, particularly over the northern foothills/I-25 corridor.
Banded snowfall in northwesterly flow often leads to some
surprises... but quickly approaching dry air shuts things off.
Look for a couple of "lucky" spots to pick up a quick inch or two,
with little to no snowfall elsewhere.
&&
.LONG TERM /Saturday night through Friday/...
Issued at 211 PM MST Fri Feb 14 2025
Northwest flow aloft prevails Saturday night between a trough to
the east and ridging to the west. The flow aloft backs westerly
Sunday as the ridge aloft flattens out as the next upper level
trough nears the region. Snowfall decreases over the mountains
Saturday evening and comes to an end overnight. Sunday starts off
dry across the area, but moisture increases and snow is expected
to redevelop over the northern mountains Sunday afternoon. Periods
of light mountain snow are expected to continue Sunday night and
through Monday under a strong and somewhat moist westerly flow
aloft.
For areas east of the mountains, a few snow showers will be
possible into Saturday evening before drier air moves in. Sunday
will be dry with temperatures a little below normal with highs in
the 30s. Lee side surface trough forms along the base of the
foothills, so this will result in a southeast to easterly low
level flow over most northeast Colorado and keep the cooler air in
the area. The southern foothills and Palmer Divide could see
southwest winds and warmer temperatures with highs possibly
reaching the 40s. This warmer air could extend northeast onto the
nearby plains.
For Monday, the surface pattern over Colorado will be somewhat
similar as Sunday with a surface trough up against the foothills,
but we will also see a low form over northern New Mexico which
will result in a northeast low level flow across the plains.
Colder air is expected to be advected into northeast Colorado
through the day, so we may end up seeing falling temperatures
Monday afternoon.
The arctic air continues to back into the area Monday night and
Tuesday with light snow accompanying it. The mountains remain
under a northwest flow aloft which should continue to bring light
snow and chilly temperatures. However, the mountains should remain
above the arctic airmass that settles over eastern Colorado.
There should be a break in snow late Tuesday and early Wednesday
as the area will be between systems. The next wave in the
northwest flow is expect to bring more light snow Wednesday to the
mountains and help keep the arctic airmass over eastern Colorado.
Will lower temperatures from what the NBM has for Tuesday and
Wednesday. The GFS model continues to be too warm, and will nudge
the forecast toward the colder ECMWF model.
For Thursday and Friday, models tend to agree some sort of
northwest flow aloft will prevail. The placement of ridges and
troughs are still unclear. Expect temperatures to remain below
normal into at least Thursday. As far as chances for snow go, the
mountains likely pick up light snow sometime during this time
period under the northwest flow aloft. For areas east of the
mountains, will keep PoPs on the low side with the uncertainty if
we`ll see a system affect the area.
&&
.AVIATION /00Z TAFS through 00Z Sunday/...
Issued at 439 PM MST Fri Feb 14 2025
Band of showers/virga was moving across DIA with gusty NW winds.
This threat will end by 00Z. For the rest of this evening, there
will be a chance of snow showers between 02z and 07z with ceilings
dropping to MVFR by 07z. Winds will generally become light and
variable around 5 kts. By 12z will see IFR ceilings with some
potential for fog. Not sure how dense it will be so have left
visbility 6sm for now. For the rest of the day on Sat, expect IFR
celings with a chance of snow showers after 21z. Winds will be
mainly from the east.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 8 PM MST Saturday for COZ031-033.
Winter Weather Advisory until 5 PM MST Saturday for COZ032.
Winter Weather Advisory until 8 PM MST Saturday for COZ034.
&&
$$
UPDATE...RPK
SHORT TERM...Hiris
LONG TERM...Meier
AVIATION...RPK
Area Forecast Discussion
National Weather Service Cheyenne WY
510 PM MST Fri Feb 14 2025
.KEY MESSAGES...
- Significant mountain snow accumulations are expected through
Saturday evening. A period of lower snowfall rates and/or a
brief lull is anticipated this afternoon and evening before
snowfall picks up again later tonight.
- After a mild Friday, temperatures will drop over the plains
once again for Saturday, with a chance for light accumulating
snow mainly in southeast Wyoming.
- An active pattern continues through mid-week with multiple
rounds of snow, frigid temperatures, and high winds possible.
&&
.SHORT TERM /THROUGH SUNDAY/...
Issued at 232 PM MST Fri Feb 14 2025
Visible satellite this afternoon shows extensive cloud cover over
the southern two-thirds of the CWA. There is some light shower
activity under some of these clouds with ASOS observations and
Interstate 80 webcams showing some light snow. Hi-Res guidance does
show showers becoming more numerous over the Interstate 80
corridor later this afternoon and evening. The RAP has decent
instability today over the aforementioned areas, leading to more
convectively driven showers. Given the temperatures across the
area this afternoon, snow showers are most likely out west and
in the mountains, while rain showers could be possible east of
the Laramie Range this afternoon before transitioning to snow
this evening as a cold front drops down from the north.
With the upper-level trough axis progged to traverse the CWA
Saturday, colder temperatures and snow chances are expected. As the
trough pushes colder air farther south, temperatures during the day
will be cold enough for snow with highs in the teens and 20s. This
progressive trough has decent mid-level moisture associated with it,
however models remain fairly modest with QPF amounts. Although
widespread precipitation is expected across the area, most locations
will see anywhere from a dusting to an inch. The mountains will
continue to get hit with snow through orographic lift, with an
additional 6 to 12 inches expected through the day Saturday. Winter
Storm Warnings remain in place through this time. Did decide to
issue a Winter Weather Advisory for the South Laramie Range for most
of the day Saturday. A strong band of frontogenesis will set up over
the South Laramie Range tomorrow afternoon. This is when the
heaviest precipitation and highest accumulations are expected.
Anywhere from 2 to 4 inches is possible under this frontogenesis
band, which could make travel difficult through the South Laramie
Range. Other areas to watch include the Arlington/Elk Mountain area
and the Cheyenne Ridge. Strong frontogenesis also exists in these
areas which could lead to over an inch of accumulation along the
Cheyenne Ridge and potentially over 3 inches in the Arlington zone.
Snow will taper off across the area Saturday evening.
As the upper-level trough exits eastward, another weak disturbance
will move into the CWA on Sunday, bringing another round of mountain
snow. Despite the mountain snow, the main concern during the day
Sunday will be the potential for high winds. This disturbance will
create a decent MSLP gradient over the area, with elevated CAG-CPR
700 mb height gradients over 55 meters. Winds aloft will max out
over the wind prones at 50 to 55 kts during the day Sunday with good
subsidence. Based on this and in-house guidance showing 60 percent
probabilities for high winds, decided to issue a High Wind Watch for
the Arlington zone. High Wind Watch starts early Sunday morning and
continues through Sunday evening. At this time, did not have enough
confidence to issue for other zones, as in-house guidance is not
showing a strong signal for high winds outside of Arlington. Despite
there being 50 kt winds aloft, subsidence does not look overly
strong to get these winds down to the surface at Bordeaux or the
South Laramie Range. Winds will ease Sunday evening as the next
storm system impacts the area.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Issued at 232 PM MST Fri Feb 14 2025
A Colorado Low will eject out of the Rocky Mountains
to the south of Wyoming to give us some snow development Sunday
night through Tuesday afternoon. Southeast Wyoming and the Nebraska
panhandle are placed into easterly flow as the Colorado passes to
our south favoring upslope for the lower elevations. There is some
isentropic lift moving through region to help strengthen the forcing
over the area to achieve higher snow totals of 1-3 inches in the
lower elevations east of I-25. Tuesday afternoon through Wednesday
evening an arctic front drops down ahead of a strong high pressure
system. This arctic front will create a large stream of frontogenesis
to lift the moisture left in the region to continue the snow
production for the area. Another 1-3 inches may be possible given
the strength of the depicted band of frontogenesis and continual
isentropic lift. The Long Range Ensemble Forecast(LREF) paints a 80
to 90 percent chance to exceed 3 inches and 10 to 15 percent chance
of exceeding 6 inches during this period for the Northern Nebraska
Panhandle (Scottsbluff and North). The areas east of I-25 excluding
the Northern Panhandle carry a 30 to 50 percent chance of exceeding
3 inches and a 10-30 percent chance of exceeding 4 inches. The
uncertainty with this is where these bands set up and how fast does
the front push through our area.
Temperatures will also be well below normal behind this front. The
biggest question in the long term forecast period is where an arctic
front will setup across the CWA. The ensembles have varied ideas on
how this front will setup across Southeast Wyoming and the Nebraska
Panhandle. The GEFS has the front the farthest north and moving
southward slowly. The GEFs also has the quickest recovery time as
another shortwave pushes the arctic airmass out eastward into the
Northern Plains. The GEPS and Euro Ens are more in line with each
other with some subtle differences in location and recovery timing.
Given the Canadian model`s good performance with arctic fronts, a
50/50 blend of Canadian and NBM was used to drop down temperatures
and to add more GEPS weight to the model blend as the GEFS was
keeping the NBM at a higher bias for warmer temperatures. However,
Thursday the regional switches from a northerly flow to a westerly
flow aloft to favor downsloping for areas east of I-25. Given the
downsloping regime a 50/50 blend of GEPS and NBM75 was used to try
to capture the warmer downsloping temperatures and the faster
recovery time as the arctic airmass pushes off to the east.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 510 PM MST Fri Feb 14 2025
An upper level trough will remain over the area and slowly push
east Saturday. A surface cold front and an upper level disturbance
will result in increase low clouds and a good chance for snow
this evening and Saturday after sunrise.
HAZARDS/WEATHER TRENDS: VFR conditions will prevail this evening,
although brief MVFR CIGS can`t be ruled out for KSNY, KBFF, and KCDR
as some rain/snow showers move east across the area. Surface cold
front is forecast to push south into Colorado this evening, with
MVFR CIGS developing across the high plains and KLAR. Snowfall will
likely hold off until after 12z to 15z Saturday. A few of these snow
bands may be heavy at times with VIS below 1/2 mile at times.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Watch from late Saturday night through Sunday
evening for WYZ110.
Winter Storm Warning until 5 PM MST Saturday for WYZ112-114.
Winter Weather Advisory from 5 AM to 11 PM MST Saturday for
WYZ116.
NE...None.
&&
$$
SHORT TERM...SF
LONG TERM...MM
AVIATION...TJT
Area Forecast Discussion
National Weather Service Dodge City KS
518 PM CST Fri Feb 14 2025
.KEY MESSAGES...
- Remnants of California storm will move out across southwest
Kansas Saturday. No impacts are expected with only a trace to
a couple tenths of an inch of snowfall mainly across far
southwest and far west central KS.
- Dangerous arctic air outbreak poised to impact southwest
Kansas beginning Monday Night. A long duration of air
temperature of +5F or colder and Wind Chill Index -20F or
colder is increasingly likely.
- Light to moderate snow forecast to accompany dangerously cold
air Tuesday with increasing confidence (60%+) of widespread
2"+ snowfall.
&&
.DISCUSSION...
Issued at 332 PM CST Fri Feb 14 2025
This afternoon`s water vapor imagery and RAP analysis showed the
remnants of the California storm moving across the Four Corners
region into the Colorado Rockies. The downslope southwest momentum
at the nose of the incoming jet streak was in full effect with a
fairly dramatic rise in temperature across the southwestern portions
of our forecast area, as 20Z (2 PM CST) obs were showing 69 to 71F
from Elkhart to Johnson to Syracuse. The warm downslope momentum was
really making a strong push deeper into west central and southwest
Kansas with 60+ obs as far northeast as Dighton to Dodge City. As
the surface low out west over eastern Colorado continues to slowly
develop, it will begin to push east with a cold front developing
late in the night across northwest Kansas. The remnants of the
California storm will continue to push east across the Central
Plains as an open trough, effectively limiting accumulating
precipitation chances. The best chances for western Kansas will be
early Saturday as the 700mb frontogenetic zone remains at least
somewhat strong when it is out over eastern Colorado into adjacent
far western Kansas. All models show this frontogenetic zone and
associated QPF dissolving as it moves farther east into southwest
and west central Kansas by midday Saturday.
Strong cold air advection will continue through the day Saturday in
the wake of this system, resulting in temperatures falling back into
the 20s much of the day on 20-30 mph north winds. As surface high
pressure ridge moves out across western Kansas Saturday Night into
Sunday, winds will diminish, becoming nearly calm at times late in
the day Sunday.
Attention then turns to Monday as the true arctic air mass begins to
make its run on western Kansas. Monday temperatures will be tricky
as the arctic front will be nearly stationary much of the day. This
is reflected in latest NBM temperatures for Monday as a 30-degree
gradient in MaxT from 57F at Elkhart to 27F at Hays. A new surface
low will develop just south of the edge of this arctic air mass
across southeastern Colorado Monday...ahead of an incoming upper
level jet streak approaches Colorado. After sunset Monday is when
dramatic changes for the much, much colder will commence. Dramatic
cold air advection will develop and continue all through the night
and into the day Tuesday. Once the temperature starts dropping, it
will continue to fall through the entire day Tuesday, perhaps
reaching below zero for much of the DDC CWA by afternoon. Latest 12z
run of 100-member Grand Ensemble has a 50th percentile 18Z (Noon
CST) temperature of only +1F at Dodge City and -3F at Hays. Wind
Chill Index will be falling into dangerous territory through the day
as well with -20 to -25F not unlikely at all on a fairly stiff north-
northeast wind of 15 to 20 mph. Light to moderate snow will break
out, as there is now greatly increased confidence in at least a
light accumulating snow event to go along with the dangerously cold
temperatures. Grand Ensemble total QPF for Monday Night through
Tuesday Night is in the 0.20 to 0.30" range for much of the western
half of Kansas, and given how cold it will be, the snow-to-liquid
ratios are expected to be well above the climatological normal,
likely greater than 15:1. Snow will likely come to an end Tuesday
Night, but the core of the coldest air will just be arriving.
Dangerously cold wind chills, colder than -20F, will likely continue
through the night and much of the day Wednesday. There continues to
be strong agreement among global models and ensemble systems of
temperatures barely reaching above 0F. The latest officially forecast
high of +8F at Dodge City may need to be lowered even more. Despite
the wind decreasing Wednesday and Wednesday Night, even a 10 mph
wind will create very dangerous wind chills down to around -20F.
With fresh snow cover and a clearing sky, Thursday morning could see
widespread lows -10F or colder, but this is highly dependent on snow
depth, clear sky, and a nearly calm wind. It will take several days
to recover from this dangerously cold air mass, and we may not see
temperatures above 32F until Friday afternoon at the earliest for
the bulk of Southwest Kansas.
End users would be encouraged to begin making early planning and
preparations for extreme temperatures, as there is very high
confidence now in a severe cold outbreak lasting at least 60 or so
hours from early Tuesday morning through Thursday or so.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 514 PM CST Fri Feb 14 2025
A storm system in the four corners region will move into the
central plains tonight. A surface low in eastern Colorado will
move into south central Kansas through the night bringing a cold
front and lower clouds into southwest Kansas. Expect winds to
switch to the northwest and be breezy at 20-30 kts for all
terminals between 07-10Z. Cloud ceilings will fall to at least
IFR category if not LIFR category with the clouds at around 10Z
and eventually lift to MVFR flight category around 18Z. VFR
flight category could be achieved by 22Z as the system exits and
clouds break up. Pockets of light snow are possible for all
terminals between 12-17Z and with the wind could reduce surface
visibilities briefly however snowfall totals are expected to be
up to 1 inch at the most.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Umscheid
AVIATION...Tatro
Area Forecast Discussion
National Weather Service Quad Cities IA IL
555 PM CST Fri Feb 14 2025
.KEY MESSAGES...
- A burst of moderate to heavy snow is possible mainly north of
I-80 from late this afternoon into early tonight.
Accumulations of 1-3" are possible across the far north and
northeast sections of the outlook area within a 2 - 5 hour
period.
- Gusty southeast winds between 25 to 35 mph may lead to periods
of shallow blowing snow and significant drifting in open and
rural areas this afternoon and evening, especially west and
north of the Quad Cities.
- Some freezing rain or drizzle is possible south of I-80 late
tonight into early Saturday AM, which could lead to slick
travel conditions.
- Additional snow is expected Saturday where another 1 to 3
inches of snow is possible, especially along and north of
Interstate 80.
- Active long term period expected as a series of waves and cold
air intrusions will drive the forecast period.
- Temperatures and wind chills will approach and probably exceed
Cold Weather Advisory levels this weekend and again midweek
next week.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 245 PM CST Fri Feb 14 2025
Active short term as a series of waves and WAA will bring
chances for snow/freezing rain and even some rain to the area
tonight through Sunday morning. The first wave is moving into
the area now. This will bring with it a period of strong
isentropic lift and 850-700mb frontogenesis on the nose of a
50-60+ kt low level jet. Additionally, strong low to mid-level
tropospheric flow will lead to a confluence of Pacific and Gulf
moisture into the region with PWATs rapidly reaching near
0.50"+. Areas south of highway 30 continue to see dry air
battling the snow. Along highway 20, heavy snow was falling just
west of the CWA. This is expected to move into the area this
afternoon. Winds have gusted to near 30kts with this heavy band.
This with the band of snow is leading to visibilities of under
1/4 mile. As such, extended the winter weather advisory south
and west to cover for this. Once this wave moves out of the
area, we may see a lull in activity.
Tomorrow, WAA will bring warmer temps into the area as another
wave pulls into the area in the morning. This warmer air will
start to melt ice aloft and could cause freezing rain. This is
especially true for a few hours tomorrow morning across the
southern CWA. WAA should warm temps up enough for this to turn
to rain or rain/snow. Any ice impacts should be short lived.
Looking towards the wave later in the day.
Snow chances return to the area, starting across the northern
advisory near 12z. Because of this, decided to extend that
advisory through 00z Sunday. Guidance has a large spread in amts
with this system, especially as it approaches the I80 corridor.
Most members have 1 to 4 inches, but some of the GEFS and even
the HRRR have 6 to 8 near the I-80 corridor. Looking at omegas
in the DGZ along with model soundings, we could see decent snow
production. My confidence is low in these large amts occurring,
but later shifts should keep an eye on trends for possible
winter storm warnings/extending current advisories south. In
addition to the chance for light snow, NW winds are forecast to
gust 30-35 mph through the day potentially making for difficult
travel conditions at times, especially overnight Saturday into
Sunday morning.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 245 PM CST Fri Feb 14 2025
Sunday...This will be a day where the local area is in a pressure
gradient battle zone, as a strong 1030+ MB arctic ridge axis juts
down the plains and MO RVR Valley, while deep cyclone occludes acrs
western NY. A raw, strong cold air advection day with northwest sfc
winds of 15 to 25 MPH producing wind chills in the low single digits
above zero, to almost 10 below during the day. The winds will also
continue to produce drifting snow acrs rural/open areas. Will have
POPs for light wrap around snow at times Sunday, but right now looks
like minimal additional wind blown accumulation. Sunday night with
the sfc ridge edging closer, there should be some wind decrease. But
ambient temps will crash with much of the deeper snowpack areas
having low temps ranging from 5 below to 15 below zero into Monday
morning. With that, even 5-10 MPH winds will make for potential cold
advisory criteria at least for areas along and north of I-80.
Monday...Latest run of ensembles and blends still suggest an
elevated F-gen snow event skirting acrs the southwest third to half
of the DVN CWA during the day into evening as a short wave trof digs
acrs the southwestern plains. Limited moisture but high SLR`s
suggest a couple inches possible in the southern CWA by late Monday
night, and maybe near advisory levels in the MO counties. Single
digit high temps look on track for a frigid Monday. Depending on
cloud cover, with ensemble suggested three sigma -20 to -22C H85 MB
temps north of I-80, some low temps in the northern and northwestern
CWA may approach 20 below with even light winds still making for 30
below or colder wind chills, thus extreme cold warning potentail
for Tue morning in these areas.
Tuesday through Thursday...The arctic regime looks to continue as
medium range blends suggest cold core closed upper low/vortex
settles acrs the upper MS RVR Valley and into the southwestern GRT
LKS through the end of the week. Energized zonal baroclinic zone
acrs the south half of the CONUS may allow the southern CWA to get
occasionally skimmed by isentropic light snow or flurry events
through at least early Wed. This while the area remains bathed in re-
enforcing arctic air and northern CAA flux with the arrival of the
large cold core upper trof/low. With long range projected thermal
profiles and taking into account ongoing snow cover, it appears that
several days of single digit to low teens for highs, and well below
zero low temps will be on tap. Thus several periods where cold
headlines may be needed for much of next week. Will advertise a dry
Thursday for now, but depending on the position of the upper low
there may be some sporadic light snow showers or flurries that day.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 555 PM CST Fri Feb 14 2025
Snow moving out of far eastern IA and nw IL early this evening
then mainly VFR conds overnight. Then another storm system will
bring more IFR/LIFR conds in snow beginning Saturday morning
and lasting much of the day. Several inches of accumulation is
expected. At KBRL there should be a wintry mix before changing
to all snow later in the afternoon. Southeast winds becoming
northeast to north by Saturday.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Winter Weather Advisory until 6 PM CST Saturday for IAZ040>042-
051>054.
Winter Weather Advisory from 3 AM to 6 PM CST Saturday for
IAZ063>068-076-077-087.
IL...Winter Weather Advisory until 6 PM CST Saturday for ILZ001-002.
Winter Weather Advisory from 3 AM to 6 PM CST Saturday for
ILZ007-015.
MO...None.
&&
$$
SHORT TERM...Gibbs
LONG TERM...12
AVIATION...Haase
Area Forecast Discussion
National Weather Service Goodland KS
720 PM MST Fri Feb 14 2025
.KEY MESSAGES...
- Light snow and some mixed precipitation tonight through
Saturday morning with accumulations up to 1".
- Light to moderate snowfall with the next system Monday and
Tuesday. Amounts similar to what occurred earlier this week.
- Dangerously cold Arctic air mass will be in the area Monday
night through Thursday morning. Overnight temperatures
potentially dropping into the 10 to 20 below range and wind
chills in the 20 to 30 below range.
&&
.UPDATE...
Issued at 719 PM MST Fri Feb 14 2025
Updated forecast to add in a mention of isolated thunder in
northeast Colorado over the next couple hours. Weak instability
aloft has increased some, which is near the backside of an
850mb shortwave moving through the area. Temps in this area via
SPC Meso Analysis are ranging from +3c to +4c. Temps at the
surface continue to slowly trend colder w/ 30s area-wide on N/NE
flow, so do not expect this convection to last much longer.
&&
.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 115 PM MST Fri Feb 14 2025
A band of light snow will move through the area tonight with a
shortwave trough. There may be a few isolated showers or even a
thunderstorm ahead of the band late this afternoon/early this
evening with HRRR showing some low MUCAPE. The main band will
have to overcome a warm layer, so may see some mixed precipitation
initially, but changing to all snow overnight as the low levels
cool. Some light snow will linger into Saturday morning before
ending. Total accumulations still expected to be 1" or less.
Lows tonight will be in the teens and highs on Saturday in the
20s with some afternoon sun trying to break out. Far western Kit
Carson and Cheyenne counties in Colorado may see some
additional light snow Saturday evening from a secondary
shortwave in the northwest flow aloft, but expecting little, if
any, additional accumulation as best chances will stay west.
Skies will then clear through Saturday night with lows in the
single digits above and wind chills as low as 10 below.
Sunday will be dry during the day as the northwest flow becomes
more zonal. Temperatures will moderate slightly with highs
ranging from the low to mid 20s in the east (McCook to Norton)
to the upper 30s in Colorado. Clouds will increase in the
afternoon with a chance for light snow Sunday night across
northern areas (Kansas/Nebraska border area). Appears to be a
weak perturbation in the flow with some help from right entrance
region of a jet streak moving through the northern plains. Any
accumulating snow amounts will be less than a half inch. Lows
Sunday night will be in the single digits and teens and wind
chills 10 to 15 below (coldest in eastern areas McCook to Hill
City).
Monday will be mostly cloudy with light snow chances continuing
across northern areas with another jet streak moving across
central Nebraska. Up to 1" of additional snow will be possible
during the day in the Kansas/Nebraska border area and generally
north of Interstate 70. Highs will range from the teens in
Nebraska to the 20s and 30s south of Interstate 70. Monday
night the Arctic air will begin to spill into the area with
increasing snow chances as a shortwave trough rotates in from
the northern plains. Lows will plummet into the single digits
below zero with wind chills 20 to 25 below. Snow amounts have
gone up for Monday night as the system has sped up somewhat.
Mean snow amounts are running around 3" with some higher
percentiles up to 5". The very cold temperatures will promote
high snow-liquid ratios. Wind still does not appear to be an
issue with gusts in the 10-15 mph range.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Issued at 115 PM MST Fri Feb 14 2025
The light snow continues into Tuesday morning but appears to
taper off Tuesday afternoon with latest timing. Additional
amounts of around 1" or so will be possible. Temperatures remain
frigid with highs in the single digits and lows Tuesday night
in the 10 to 15 below range despite cloudy skies. Wind chills
will be 20 to 25 below.
An upper low over the northern plains Tuesday will move to the
Great Lakes by Thursday. This will continue to pump Arctic air
into the region. However, snow chances will be low after Tuesday
with a couple of fast moving waves moving across the central
plains. The main focus will be the bitterly cold temperatures.
Highs on Wednesday will be in the single digits and teens but
falling into the single digits and teens below zero Wednesday
night and Thursday morning. Lows around 20 below cannot be ruled
out, with the minimum temperature EFI (Extreme Forecast Index)
near -1 (lowest on the scale) and lower percentile temperatures
20 to 25 below. The potentially extreme temperatures cannot be
emphasized enough from Monday night through Thursday morning.
Finally start to see some relief Thursday and Friday with highs
in the 20s Thursday and 30s on Friday with dry conditions.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 343 PM MST Fri Feb 14 2025
For KGLD, VFR conditions through 06z Saturday then an MVFR/IFR
mix with 4-6sm in snow and ceilings around OVC010. VFR resumes
from 20z onward. Winds, northeast around 10kts becoming north
by 04z. From 06z Saturday onward, northerly 10-15kts w/ gusts
to 25 kts from 13z-20z.
For KMCK, VFR conditions through 05z Saturday then an MVFR/IFR
mix with 4sm in snow and ceilings around OVC010-015. VFR
resumes from 18z onward. Winds, northeast around 10kts becoming
north by 05z. From 08z Saturday onward, northerly 10-15kts w/
gusts to 25 kts from 08z-18z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
UPDATE...JN
SHORT TERM...024
LONG TERM...024
AVIATION...JN
Area Forecast Discussion
National Weather Service Green Bay WI
627 PM CST Fri Feb 14 2025
Updated aviation portion for 00Z TAF issuance
.KEY MESSAGES...
- Hazardous travel conditions are expected through Saturday
afternoon with a 60-80% chance for greater than 4 inches of snow
in most areas. Worst travel conditions should occur along and
south of Highway 29 and the Lakeshore this evening, due to
snowfall rates approaching 1 inch per hour. Lake-enhanced snow
may also occur over Door County late tonight into Saturday
morning.
- Lake effect snow showers could bring additional light snow to
eastern Wisconsin Saturday night into Sunday morning, resulting
in hazardous travel.
- Gusty northerly winds on Sunday could lead to minor blowing and
drifting snow, especially along the lakeshore and bayshore.
Periods of reduced visibilities will be possible.
- Bitterly cold wind chills are expected to return for the early
to mid part of next week. Coldest readings are expected to occur
Monday and Tuesday mornings, with wind chills dropping to 20 to
35 degrees below zero, locally colder.
&&
.DISCUSSION...
Issued at 141 PM CST Fri Feb 14 2025
Short Term...Tonight and Saturday
The latest RAP analysis and satellite/radar imagery show a
confluent upper air pattern across the northern Plains/western
Great Lakes early this afternoon. A coupled upper jet structure
within this pattern is leading to a 50 kt low level jet nosing
into southern Minnesota early this afternoon, but dry air as
evident by the 12z MPX sounding shows ample dry air (precipitable
water values = 0.13") that needs to be overcome before widespread
snow develops. Starting to see a few surface obs showing snow is
reaching the ground over Minnesota and western Wisconsin.
Otherwise, clouds continue to increase across the region with
temperatures in the single digits to mid teens.
Forecast concerns continue to revolve around forecast snow
accumulation trends and headline changes through Saturday.
Widespread snow remains expected to grow upscale through the
afternoon as strong lift on the nose of the low level jet
eventually overwhelms the dry air and leads to deep saturation.
This snow will then proceed east to spread across the entire area
this evening thanks to strong warm advection beneath a coupled jet
structure.
Precipitation amounts as well as snowfall intensities have trended
down for the evening snow over the past 24 hours as probabilities
for 1"/hr snowfall rates have diminished to around 20-30 pct as
opposed to 40-60% yesterday. Despite continued signals for a
200-300mb deep DGZ, snowfall amounts have trended down into the
3-5" range during the warm advection part of the snows through
early overnight. It doesn`t appear that this part of the system
will be sufficient to bump up impacts into warning criteria.
The 2nd phase of the system arrives late overnight through early
Saturday afternoon, when CAMS indicate a frontogenetical band of
precipitation developing and impacting areas from central WI to
the Door Peninsula. Snowfall amounts continue to look to be about
1-3" within this band before it weakens Saturday afternoon.
Additionally, indications remain for a lake band to affect the
Door Peninsula late tonight into Saturday morning. While snowfall
intensities and amounts will be higher in the band, the band looks
relatively transient and short-lived so not confident that it
will be sufficient to boost them up into a warning. The
combination of the two parts brings snowfall ranges from 2-4"
across far northern WI to 6-8" from Wisconsin Rapids to northern
Door.
Because snowfall intensities are trending down with the
first event and not high enough for the 2nd part of the event,
decided to stick with a prolonged Winter Weather Advisory. Delayed
the start time of the advisory by 1 hour and reconfigured the
zones to help with the details for the 2nd part of the event. Then
extended the end time of the Advisory for central, east-central,
and the lakeshore through 21Z Saturday.
Long Term...Saturday Night Through Friday
Volatile forecast continues as low pressure currently over
Colorado appears to be the gift that keeps on giving.
Accumulating snow now looks to persist across east-central
Wisconsin through at least Sunday morning, adding another couple
inches of light, powdery snow to the lakeshore counties. Winds
likewise ramp up Sunday morning, creating potential for minor
blowing and drifting snow. Confidence continues to increase in the
necessity for cold weather headlines early next week.
Sunday snow potential... Surface low continues to deepen as it
tracks across the Ohio Valley Saturday night. Winds then veer to
north/northeasterly over a large fetch of the lake early Sunday
morning, resulting in potential for additional lake-enhanced
accumulations along the Door Peninsula as 700 mb PVA and coupled
jet structure exit the Great Lakes. Snowfall window will likely be
limited as winds continue to back to northwesterly after 12Z
Sunday, keeping any banding offshore. Where exactly the
convergence band will set up (if at all) and whether or not it
will hold together is still up for debate, as FGEN and deep-layer
shear become progressively more unorganized. If it were to
materialize, this would be a scenario in which Manitowoc and
Kewaunee counties could pick up another few inches of light,
fluffy snow through Sunday afternoon.
Winds... Arctic high pressure approaches from the northwest early
Sunday morning as anomalous low (~3 standard deviations below
average) departs to the northeast. Result will be east/west-
oriented pressure gradient tightening up over Wisconsin, with
surface gusts between 25 and 30 mph possible. Main concern will
be minor impacts from blowing and drifting as light snow
continues to fall along the Lake Michigan shoreline. Light/powdery
snow character may also result in periods of reduced
visibilities, so caution is advised if traveling on Sunday.
Dangerous wind chills... As aforementioned arctic high sits and
spins over the northern Plains, 850 mb temperatures fall to -25
to -28C (around first percentile compared to climatology) Monday
and Tuesday mornings. Cold weather headlines appear to be likely
during this time, when wind chills plunge to 20 to 35 degrees
below zero. Low temps may even overperform given several opportunities
for clearing paired with a persistent snow pack. Have thus opted
to lower hourly temps Monday, Tuesday, and Wednesday mornings
accordingly. Margin becomes a little tighter Wednesday morning as
hourly temperatures rebound a few degrees. Will continue to
monitor throughout the weekend.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 627 PM CST Fri Feb 14 2025
Flying conditions will continue to deteriorate this evening as
light and moderate snow spreads across the region, with a mix of
MVFR/IFR/LIFR conditions. A period of heavy snow is expected this
evening, dropping visibility to around 1/4 mile. While the snow
will depart/diminish between 06-09z across north-central WI,
light to moderate snow is expected to continue (with some lulls),
generally south of a KCWA to K2P2 into Saturday. A lake effect
snow band may impact MTW late on Saturday as well. Southeast
winds will gust up to ~15 kts this evening, highest in central WI
and along the lake shore, before winds diminish for a time late
overnight into Saturday morning. Winds will switch to the
northeast on Saturday, gusting to ~15 kts.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 AM CST Saturday for WIZ005-
010>013-018>021-030.
Winter Weather Advisory until 6 PM CST Saturday for WIZ022-040-
050.
Winter Weather Advisory until 6 PM CST Saturday for WIZ031-
037>039-048-049-073-074.
Winter Weather Advisory until 6 PM CST Saturday for WIZ035-036-
045.
&&
$$
DISCUSSION.....MPC/Goodin
AVIATION.......Bersch
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
802 PM EST Fri Feb 14 2025
.KEY MESSAGES...
- High water will persist at some points along the main stem
rivers today.
- Heavy rainfall, along with a round or two of thunderstorms, this
weekend could lead to significant flash flooding and river
flooding.
- Accumulating snowfall is possible for the middle of the upcoming
work week.
&&
.UPDATE...
Issued at 759 PM EST FRI FEB 14 2025
Hourly grids have been freshened up based on recent observations.
A few MPING reports of sleet or flurries have been noted from IL
and IN over the past couple of hours, with even a recent MPING
flurry report in west central KY. A bit more of flurry or non
measurable precipitation in the form of sleet falling from mid
level clouds may need to be added to the grids for later this
evening into the start of the overnight. As warm advection occurs
and the atmosphere continues to moisten from the top down. No
impacts are expected from this and as temperatures creep up
overnight and more lower clouds arrive, steady measurable rain
should develop late tonight to early Saturday as the lower levels
of the atmosphere gradually saturate ahead of an approaching low
pressure system.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 450 PM EST FRI FEB 14 2025
***HIGH IMPACT FLASH FLOODING/RIVER FLOODING STILL POSSIBLE THIS
WEEKEND***
220Z sfc analysis shows high pressure well off to the northeast now
as attention begins to turn to developing low pressure over the
Central Plains. For now, though, the high has held off the higher
clouds arriving until just recently from the west. The ample
morning and early afternoon sunshine and light winds helped
temperatures rebound from very chilly lows this morning - reaching
the upper 30s north and mid 40s south where readings generally
sit at this time. Meanwhile, dewpoints are mostly in the mid to
upper teens.
The models, and their individual ensemble suites, are still in
pretty good agreement aloft through the short term portion of the
forecast. They all depict flat ridging over the Southeast to start
the period while a deep trough digs and consolidates over the Four
Corners Region tonight. This will support increasingly fast, deep
layer, southwesterly flow to the downstream scouring moisture from
the Gulf of America into our region through the weekend. Some
weak energy will move through the mid level flow into Saturday
morning before the larger height falls and core of the western
trough approaches the state later Saturday night. This system will
punch through the area aloft around or just after 12Z Sunday -
about the time a coupled jet structure passes by at 3h. In fact,
prior to that, a series of strong 3h jets will be to the north of
the Ohio River placing eastern Kentucky in the right rear quadrant
for enhanced lift at various times during this event. For
Saturday and into Saturday night, climatologically very high PW
air will be in place over the area, though highest just off to the
northwest of most of the JKL CWA and away from the headwaters of
our larger rivers. The still rather small model spread aloft again
supported using the NBM the starting point for the forecast
grids, though with some adjustments for temperatures this evening
to account for some minor terrain distinctions. Did also
incorporate some of the latest CAM ideas into PoPs on Saturday and
Saturday night.
Sensible weather features a potential for a high impact flooding
event this weekend for parts of the region. On the positive side
the model consensus for where the warm front sets up and the zone
of heaviest rain has shifted northwest of our most vulnerable
locations but this has served to lower confidence in the overall
rainfall amounts and blunted the higher end totals from 24 hours
ago and high impact potential. Now that the trough has come ashore
on the West Coast we can take some comfort noting that it should
be well sampled and typically this leads to a better model handle
on the impacts further east. Though confidence is lowered for the
actual amounts the trend is in the right direction. That said
there will still probably be significant impacts for the area even
with the current thoughts of the heavy rain axis to the north and
west of the main JKL rivers. This includes the Red River through
Powell and Estill counties and the Licking River and Triplett
Creek as well as areas along and to the north of I-64. Significant
flash flooding will be a large concern through the event, but
particularly Saturday evening and night due to the potential for
training cells, thunderstorms, high rainfall rates, and still
soggy soils. The rain will arrive from the west before dawn and
quickly work east with thunder a possibility in the western
Cumberland Valley Saturday morning. We are forecasting a lull in
the activity for much of the area during the afternoon as the
parent system`s warm front lifts north through this part of the
state before stalling - leaving the bulk of the JKL CWA in the
system`s warm sector. Any showers or individual cells out ahead
of the main return convective line associated with the cold front
late that evening and into the overnight will also need to be
watched for signs of organization and rotation, though much better
instability will likely stay west of the area. Nevertheless, SPC
does still have southwestern parts of eastern Kentucky under a
Marginal Risk for severe storms with damaging wind gusts the main
concern but also a non-zero chance for a tornado or two. The cold
front then plows east through the night with some of the heaviest,
but hopefully as progressive as the models currently indicate,
moving through into early Sunday morning. A caveat to that last
thought is the latest 18Z HRRR is indicating more rain than
current forecasted in the headwaters due to the convection with
that front staying rather robust all the way to the Virginia
border. This potential will need to be watched as it works against
the larger model trend of heaviest rain staying to the northwest.
Finally, it is interesting to note that warmest temperatures will
occur for most of the area just ahead of the cold front on
Saturday evening and early in the overnight - helping to sustain
the convection.
The changes to the NBM starting point consisted primarily of
adjusting the temperatures for terrain distinctions this evening.
For PoPs: did enhance the guidance from the NBM to incorporate
more details From the latest CAMs consensus on Saturday and
Saturday night.
.LONG TERM...(Sunday through Friday)
Issued at 313 PM EST FRI FEB 14 2025
The extended period of the forecast still looks to be quite active,
as a couple of powerful storm systems move through the eastern half
of the CONUS. The latest runs of the GFS, ECMWF, and GFS Ensembles
were used in the construction of the extended including the
initial large scale pattern and how it is expected to evolve
through out the period. To start things off, a large trough of
low pressure will be moving quickly through the Great Lakes, Ohio
Valley, and into New England Sunday and Sunday night. Another
trough of low pressure aloft will be moving across southern
Canada, with another large trough move into southwestern Canada
and the Pacific Northwest. Some ridging aloft will be in place
over the southwestern CONUS. The eastern trough will be departing
our area Sunday and Sunday evening. We will see rain initially,
before the coldest air spills into the region behind a departing
cold front. Temperatures will fall throughout the day, as winds
behind the front shift from the west to the northwest. Rain will
mix with and quickly change to snow late Sunday into Sunday
evening. Due to how fast the precip will be moving out of the
area, little if any snow accumulations are expected. The precip
should come to an end early Sunday evening.
After the first system moves away, an elongated ridge of high
pressure will move in from the Great Plains, and will settle over
the area Sunday night through Tuesday. The ridge will bring dry
weather to the area, but it will be considerably colder, as a
Canadian air mass filters into the region. We will see highs in the
50s over the weekend, followed quickly by daytime maxes in the 30s
for most of the area Monday and Tuesday. Before the air mass has a
chance to modify, we will have another series of storms move through
the region Tuesday night through Thursday. The first of these two
systems will take shape over the central Plains, and will move
across our area Tuesday night and Wednesday. This system will bring
a shot of colder air into the region. In fact, it will be cold
enough for this first storm to produce all snow for most of our area
heading into mid-week. A few locations along the Virginia border
might be just warm enough to allow some rain to mix with the snow to
begin the event. After the first low moves through on Wednesday, a
fast moving clipper type system will quickly follow Wednesday night
and Thursday, and will bring a shot of even colder air into the
region. The current trends in the long term models continue to show
accumulating snowfall with both of these systems, with the second
system potentially producing more significant totals. The model data
is still uncertainty regarding the exact tracks of the two mid-week
systems, and therefore where the highest snow totals will occur and
how much total snow we will see. Due to this uncertainty, we will
say for now that light snow accumulations will be possible Tuesday
night and Wednesday, with potentially higher amounts possible
Wednesday and Thursday.
Temperatures will start off well above normal on Sunday, with highs
in the 50s expected, with well below normal, and downright cold,
temperatures on tap Monday through Friday. The coolest days will see
highs in 20s and lower 30s. Lows could even fall into the teens
Wednesday night and Friday night, and the single digits Thursday
night. Weather hazards in the extended will be any issues we are
still having due to high water Sunday through Monday along with any
impacts we potentially see due to snowfall and colder temperatures
Tuesday night through Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 735 PM EST FRI FEB 14 2025
VFR conditions prevailed at TAF issuance with light and variable
winds. Some radar returns over west central KY and over parts of
IN and IL were resulting in non impactful flurries or a touch of
sleet. Steadier rain with reductions in visibility or ceilings
should not occur until closer to 12Z or later. The current clouds
are mainly mid and high level, however as the column continues to
saturate lower clouds should arrive after 09Z, with ceilings
deteriorating to MVFR and then IFR or lower from west to east
between 12Z and 18Z and remaining in those categories through the
end of the period near and in advance of a warm front. A band of
steadier rain should develop from west to east from around 09Z to
around 12Z and linger into the afternoon before starting to
diminish from south to north toward 00Z as the boundary gradually
lifts north. Some isolated thunder is also possible within this
after about 15Z, especially nearer to KSYM and KLOZ though
confidence in location and probability remained too low for even a
prob 30 inclusion late. Winds will remain light and variable
through around 06Z, but then begin to pick up between 06Z and 12Z
from southeast to south at up to 10KT. Southeast to south winds
should then prevail through the end of the period at generally 5
to 10KT with some gusts up to 20KT or higher near or south of KSME
to KLOZ to KJKL and points south. Just off the sfc as a LLJ
transports moisture in at the lower levels, winds will increase
from the south to south southwest at upwards of 40KT to 50KT
leading to a threat of LLWS at least at times for the entire area
through the end of the period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 4 AM EST Saturday through Sunday evening for
KYZ044-050>052-058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...JP
Area Forecast Discussion
National Weather Service Nashville TN
846 PM CST Fri Feb 14 2025
...New UPDATE...
.KEY MESSAGES...
Updated at 822 PM CST Fri Feb 14 2025
- A Flood Watch is in effect from 12 AM Saturday through 12 PM
Sunday for all of Middle Tennessee for significant rainfall
impacts.
- River/creek flooding continues to look more likely, with 2 to 5
inches of rainfall expected over the weekend.
- There is a Slight Risk (level 2 out of 5) for severe weather on
Saturday, mainly for areas west of I-24.
&&
.UPDATE...
Issued at 822 PM CST Fri Feb 14 2025
The radar is quiet for now but that will change. Showers and
storms will begin to move into the area after midnight as moisture
advection really ramps up. The PWAT off of the 00z OHX sounding
was 0.46". By 12z, models have PWAT values in the Nashville metro
area around 1.3" which is already approaching the daily max
values. The 00z high resolution suite of models are coming in as I
type and the results vary as far as rainfall amounts. There is a
high probability that a large area picks up 2-3 inches by 18z
which could begin to cause some flooding issues. The total
rainfall amounts for the whole event will depend on how fast the
warm front will lift through the area. It will also depend on how
far north the pivot point between the warm front and the cold
front make it. The 00z suite of high res models are generally a
little further south with that pivot point than the 12z runs which
brings the band of heaviest rain in play for our northwestern
counties. We will need to monitor to see if this trend continues.
Even with the slight southeastward jog of this heavy band of
rainfall amounts, we expected the highest amounts for the event
to be in the northwest.
As far as the severe potential, shear continues to not be
questioned. We`ll have plenty of that. The question will be how
far north ahead of the forced line of storms the instability makes
it. The high resolution models vary in the answer to that question
with the HRRR being the most bullish with over 500 J/kg of mlCAPE
in the southwest during the evening hours. Models do continue to
agree that whatever instability we have will begin to wane as the
line of storms move east of I-65. The timing still looks about the
same with the line of storms likely crossing the Tennessee River
around 4-7 PM and exiting the plateau by 2-4 AM. The main threats
for tomorrow evening will be damaging straight line winds and
tornadoes in additions to the flooding threat.
&&
.SHORT TERM...
(Rest of today through Saturday)
Issued at 1141 AM CST Fri Feb 14 2025
Clouds are pushing east across the southeast and mid-south on
satellite this morning. The severe weather threat on Saturday is two
fold: flooding threat and severe storms threat. A negatively tilted
trough will advance on the area from the west into Saturday, with
strong WAA at both 700mb and 850mb and a screaming low-level jet
with winds up to 70kts ahead of the cold front. This places middle
and western Tennessee in the warm sector ahead of the front, which
is one of the main factors in both of the threats. With ample
moisture (PWATs are 3 standard deviations above climatology in NW
TN), it`s no surprise that this area will be the heaviest rainfall.
While the highest rainfall amounts have overall taken a NW jog over
the past 24 hours out of our FA, areas in our far NW counties west
of I-24 and north of I-40 are still in the hot seat for possible
rainfall amounts over 5 inches. The probability for this has
decreased (from 40-50% yesterday to 20-30% today), but I wouldn`t
rule out isolated totals over 5 inches, especially in areas that see
thunderstorms. South of I-40, expected totals are around 1.5" to 3",
so the whole area can expect at least an inch of rain as of now.
More on the severe threat in the long term below.
&&
.LONG TERM...
(Saturday Night through next Friday)
Issued at 1141 AM CST Fri Feb 14 2025
Of course then we add in another layer of complexity into the
forecast with a slight risk for our area Saturday evening from SPC.
As the low pressure system advances from the west, the LLJ will push
east and provide more shear to the area. This shear combined with
the warm moist air in the warm sector, creates some concerns for
discrete supercells ahead of the cold front late Saturday/early
Sunday. The area most at risk for these discrete storms would be
along and west of I-24, and all modes of severe weather (tornadoes,
large hail, and damaging winds) are possible. Discrete cells would
show more of a tornado threat, whereas the cold front itself would
be more of a damaging wind threat. The window for these discrete
cells ahead of the cold front appears to be limited as the cold
front quickly closes that opportunity by surging to the east in
guidance.
Once we get into the work week, we will have a quiet period to
start. The cold front will bring much colder temperatures to middle
Tennessee, and while the colder air will bring the possibility for a
wintry mix/some snowflakes north of I-40, no accumulation or impacts
are expected. There is the possibility for another shot of
snow/wintry precipitation in the guidance mid-week next week, but
confidence is low in this solution as of now with how far out into
the future the system is in the guidance.
&&
.AVIATION...
(00Z TAFS)
Issued at 550 PM CST Fri Feb 14 2025
VFR conditions expected this evening and for most of the night at
all terminals. Early Saturday morning rain will begin to move in
from the west bringing reduced visibilities and low cigs to CKV
before 12z, then spreading to eastern terminals through mid
morning. Meanwhile, winds will become gusty out of the south,
while the low level jet increases, prompting mention of low level
wind shear for a couple of hours before showers begin. Showers
should lift north and allow for a break in precip during the
afternoon across the area. Cigs may linger around MVFR/VFR levels
until the cold front sweeps across the area after 00z tomorrow
night.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 42 67 39 47 / 90 100 100 30
Clarksville 37 64 35 41 / 90 100 100 20
Crossville 36 59 37 52 / 70 90 100 70
Columbia 41 67 37 50 / 80 90 100 20
Cookeville 39 62 37 52 / 80 90 100 60
Jamestown 36 60 35 52 / 70 90 100 60
Lawrenceburg 42 67 39 52 / 70 90 100 20
Murfreesboro 40 67 38 52 / 80 90 100 40
Waverly 37 65 34 43 / 90 100 100 20
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
Flood Watch from midnight CST tonight through Sunday morning for
TNZ005>011-023>034-056>066-075-077>080-093>095.
&&
$$
UPDATE.......Reagan
SHORT TERM...Holley
LONG TERM....Holley
AVIATION.....Whitehead