Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/11/25
AREA FORECAST DISCUSSION
National Weather Service Albany NY
929 PM EST Mon Feb 10 2025
.SYNOPSIS...
High pressure will build in south of the region
tonight with the lake effect snow showers lifting northward
into the western Adirondacks region with light accumulations.
A weak cold front will move through tomorrow with some scattered
snow showers and flurries north of the Capital Region, as a storm
system passing to the south may bring some very light snow to the
Interstate 84 corridor. Another complex storm system brings a
widespread wintry mix to the region Wednesday night through Thursday.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Key Message:
- Lake effect snowband lifts northward into the western
Adirondacks and weakens tonight with light snow accums.
.Update...As of 925 PM EST...Scattered lake effect snow showers
noted on the previous update have diminished and shifted
northward, and per KTYX are located mainly in northern Herkimer
and Hamilton counties. They will remain there through the night,
with clear to partly cloudy skies elsewhere. Adjusted POPs for
the lake effect in this update, with little changes made
elsewhere with the forecast on track. See previous discussion
below...
Previous Discussion...Diffuse lake effect snow showers and
flurries from the northern Catskills, Greater Capital Region,
north- central Taconics, Berkshires northward to the Mohawk
Valley, Saratoga Region and southern VT will weaken early this
evening. As any lake effect snowband activity will shift
northward, as the low to mid level flows backs as high pressure
builds in from PA and NJ.
The Canadian RGEM/3-km HRRR have more robust activity lifting
northward into the western Adirondacks, especially along and
north of RT 28 and Old Forge. A few inches of snow may fall
over Stillwater Reservoir and the Wilderness areas. It will
depend on the lake trajectory extension and in an environment
of lake conditional instability with the low-level inversion
down to 4-5 kft AGL.
Clouds will likely thin a bit south of the lake activity. This
may occur from the Capital Region/I-90 corridor south and east
and we leaned closer to the colder MAVMOS with partly cloudy to
mostly clear skies, as temps will plummet with light to calm
winds and a fresher snow cover. If the Lake George and Glens
Falls area clears very cold reading may occur. Overall, have
lows in the single digits to lower teens near I-84. A few below
zero readings are possible in the Adirondack Park and Lake
George Region.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
Key Message:
- Weak coastal low Tue night into Wed looks to remain mainly
south of our region, but there is a 20 percent chance for at
least one inch of snow near the I-84 corridor of southern
Dutchess and southern Litchfield Counties.
- Storm system with snow changing to mixed precipitation
expected Wednesday night through Thursday morning with
increasing probabilities for light to moderate snow accums and
a light glaze of ice.
Discussion:
Tomorrow...the surface high shifts off the East Coast and
remains south of southern New England. The mid and upper level
flow becomes zonal. The lake effect will diminish, as a
northern stream short-wave and weak cold front will move across
the region with some scattered snow shower and flurries over the
Adirondack Park and the Lake George Region. The low-level
moisture is limited further to the south and east, but clouds
will increase. Meanwhile, mid and high clouds will increase from
the winter storm system impacting the Mid Atlantic Region.
Below normal temps are expected once again, with highs in the
upper 20s to lower 30s in the valley areas and upper teens and
mid 20s over the hills and mtns.
Tue night...The consensus from the short-range guidance
including the ensembles and WPC is that coastal low will remain
well to south of the region with little to no impact with just
an increase of clouds and some very light snow possibly reaching
the I-84 corridor of southern Ulster, Dutchess and Litchfield
Counties. NBM probabilities in these area for an 1" or more of
snow remain at 20% or less. We kept some slight and low chance
PoPs in these areas with dusting to less than a half an inch.
High pressure will be building in from the southern Quebec Tue
night. There should be a sharp cutoff in the cloud cover north
of I-90. Lows will fall back into the single digits north of
Albany and mainly teens south with some below zero readings in
the southern Dacks.
By Wednesday, the coastal low tracks well to the south and east
into the western Atlantic Ocean. A 1036 hPa sfc anticyclone to
the north slowly slides eastward over Quebec to the Gulf of St
Lawrence as the zonal flow break down as a complex low pressure
system approaches from the Midwest and Kentucky Wed evening.
Mid and high clouds will increase from the south and west with
the southwesterly flow aloft. Low and mid level warm advection
will increase and it looks like any warm advection pcpn will
hold off until at night. Highs will be in the 20s to lower 30s.
Wed night-Thu...The next impactful winter system arrives with
another wintry mix. The low-level warm advection increases
associated with an inverted sfc trough and a warm front well to
the south. Some cold air air damming occurs and sufficiently
cold enough air is in place for snowfall for the onset. The 2"
snow probabilities form the the latest NBM4.2 are 40-60% over
the Adirondack Park, parts of the Lake George northern Saratoga
Region, southern VT and the eastern Catskills. Our latest
forecast is for 1-3" in many of the valley areas with some 2-4"
amounts over the higher terrain, except the northern mountains
and southern VT where 3-6" before a transition to sleet and
freezing rain occurs as the warm nose sneaks aloft and some
colder air remains trapped at the sfc. Lows in the teens and 20s
will steadily rise Wed night.
Shallow cold air remains trapped at the sfc, but gradually
erodes Thu morning with coatings to less than a tenth of an inch
advertised. The sfc high releases as the primary low moves into
the eastern Great Lakes Region. A secondary low forms near NJ
and Long Island for any mixed pcpn...which will do have changing
to rain in the valleys and south of I-90 for a time. We will
likely need advisories for most of the region Wed night into
Thu. Tough to tell if any warning headlines are needed over the
north with lows probs from WPC. Temps briefly warm up into the
mid 30s to around 40F in the lower elevations with upper 20s to
lower/mid 30s over the mtns. We stayed close to the NBM profiles
for temps Wed night into Thu for now.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Key Messages:
- Another storm system looks to impact the region over the weekend
with widespread precipitation, with snow, mixed precipitation and or
rain across eastern New York and western New England.
Discussion:
Windy conditions will develop Thu night as a storm system exits off
the New England coast and high pressure builds east across the Ohio
Valley and Great Lakes. NW flow will also provide chances for lake
effect snow showers mainly over the Mohawk/Schoharie Valleys. It
will turn colder with lows ranging from the single digits to 10s.
High pressure will then build east into our area on Fri, resulting
in lake effect snow showers ending and winds becoming lighter later
in the day. It will remain cool with highs ranging from the upper
10s to lower 30s. Dry and cold conditions expected Sat night as high
pressure gradually shifts east of the region.
The weather then becomes more active Sat into Sun, as a significant
storm system approaches from the south/west and tracks northeastward
across the region. There is considerable spread among the
deterministic and ensemble guidance with regards to the storm track
and associated QPF and precip types. At this time is appears that
with a sufficiently cold air mass in place any precip would likely
start as snow on Sat, then possibly transition to a wintry mix Sat
night into Sun, with some areas even changing to rain. However,
there is low confidence in precipitation transitions as well as
snowfall/ice amounts. The latest long range forecast ensemble
probabilities show a 20-70 percent chance for > 4" snow going from
south to north, along with a 20-30 percent chance for > 0.1" ice
from north to south across the area. There is at least higher
confidence for moderate to moderate to heavy precip. This system
looks to exit Sun night into Mon, with windy and colder conditions
developing in its wake.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
Through 00z Wednesday...VFR conditions expected to prevail through
the 24 hour TAF period. Lake enhanced clouds moving across the
KALB/KGFL/KPSF TAF sites through this evening, possibly lingering a
few more hours at KGFL. Mid level clouds will gradually increase
again on Tuesday, with cigs remaining at VFR levels. Winds will
initially be northwest around 6-12 kt, becoming variable at less
than 5 kt overnight. Winds will shift to the southwest around 5-10
kt on Tuesday.
Outlook...
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.
Wednesday Night: High Operational Impact. Breezy. Definite SN...SLEET.
Thursday: High Operational Impact. Breezy. Definite RA...SN...FZRA.
Thursday Night: Low Operational Impact. Breezy. Slight Chance of SHSN.
Friday: Low Operational Impact. Breezy. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: High Operational Impact. Likely SN.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Wasula
NEAR TERM...Speck/Wasula
SHORT TERM...Wasula
LONG TERM...JPV
AVIATION...JPV
Area Forecast Discussion
National Weather Service Cleveland OH
906 PM EST Mon Feb 10 2025
.SYNOPSIS...
High pressure will slowly east east towards the Mid-Atlantic
Coast through tonight. A weak cold front will settle south
across the area Tuesday night. Low pressure will track northeast
into the region Wednesday night into Thursday, followed by high
pressure on Friday.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
905 PM Update...
Quiet evening with cirrus streaming in from the west. Not as
cold overnight except for NW PA which is still expected to be in
the low to mid teens. Further west, primarily low 20s expected.
Dry through the overnight. No major forecast changes.
Previous Discussion...
Mainly quiet weather is expected through the near term period as
high pressure exits towards the east tonight and a low
pressure system skirts just to the south of the region on
Tuesday.
Diurnal-cu will gradually dissipate following sunset this
evening and will be replaced by arriving high cirrus. Clouds
will thicken overnight ahead of a low pressure system which will
move east through the Tennessee Valley towards the Mid-Atlantic
late tonight through Tuesday. Latest RAP guidance suggests
limited potential for a light dusting of snow across the far
south, generally along and south of the US-30 corridor and along
and east of the I-71 corridor, late Tuesday morning and early
afternoon. Otherwise, quiet weather should persist across the
rest of the area as the region remains underneath split mid and
upper-level flow regimes.
Below average highs in the low 30s are expected for Tuesday
with near to slightly below average nighttime temperatures in
the upper teens to lower 20s for tonight and Tuesday night.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
High pressure will be skirting north of the Great Lakes region
briefly Wednesday morning into the afternoon before building off
into eastern Canada. A surface low pressure system will eject out of
the mid-Mississippi Valley into the northern Ohio River Valley
Wednesday evening dragging a cold front along with it. Precipitation
will start in the afternoon hours Wednesday, spreading west to east,
and increase as the low pressure moves across the region Wednesday
night. The surface low will push off into eastern Canada on Thursday
and the precipitation chances will drop off with it. There is the
potential for some additional precipitation in the form of snowfall
across the primary snowbelt with westerly cold air advection behind
the low through Thursday night.
For the low pressure system on Wednesday, there is decent model and
ensemble agreement on the track of the low and the general
placement. The consensus is the low will move across the lower Great
Lakes early Thursday morning, which has trended more north over
recent runs. A discrepancy the models do have with each other is the
strength of the low. The GFS has kept a weaker low as it moves into
the region where as most of the other models have it sub 1000 mb.
The models have also started to trend warmer across most of northern
OH, which will impact what type of precipitation will fall.
Precipitation will start out as snow for mostly everyone before
transitioning over to a wintry mix of rain/snow/freezing rain. Rain
will then be the main precipitation type across the eastern part of
OH until early Thursday morning when it will go to a rain/snow mix
and then over the primarily snow as precipitation tapers off to the
east.
As for winter precipitation totals across the region, the most
impactful will be in NW OH and NW PA with the freezing
precipitation. Those areas could see a few hundredths of an inch of
ice and in the most persistent locations could see around a tenth of
an inch of ice by Thursday morning. For snow totals, there has been
a downward trend as the models have trended warmer and currently
have between 1-3" for far NW OH. Elsewhere, areas north of U.S.
Route 30 will see less than an inch and tapering off quickly to the
south as rain will be the primary precipitation type.
As mentioned above, temperatures have been trending warmer over the
past few model runs. Wednesday highs will reach above freezing for
most and into the mid 30s for areas south of U.S. Route 30. The
highs for Thursday will occur in the overnight hours before the cold
front moves through the region. There will be a short time frame
where the warm front will push northward and temperatures will reach
into the mid to upper 30s for areas east of I-75. After the cold
front moves through, temperatures will drop down into the upper 20s
during the day on Thursday and with some stronger westerly winds
will bring the wind chill down into the upper teens. Overnight lows
on Thursday will drop down into the mid to low teens.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
High pressure will build in on Friday behind the low pressure from
Thursday and dry weather will be expected through Friday evening.
Precipitation chances will start to increase early Saturday morning
as another low pressure system, following a similar track to the mid
week storm, moves into the region. There`s still quite a bit
discrepancies with the models and ensembles on the track of the
surface low pressure system, but there is high confidence in the
precipitation chances for the day Saturday. Given the uncertainty in
the track of the low, there is uncertainty in what type of
precipitation will fall with this system. There should be widespread
snow chances across the region with some rain/snow mix in there as
well at times. With the uncertainty, it`s difficult to say snowfall
totals, but it`s trending towards being impactful accumulation
across the region. Precipitation chances will decrease as the low
pressure pushes off east and high pressure builds in overnight
Sunday into Monday morning.
Temperatures will be in the upper 20s for Friday and Sunday for
highs with Saturday being the warmest day with highs in the mid to
upper 30s across the region.
&&
.AVIATION /00Z Tuesday THROUGH Saturday/...
SCT-BKN cloud deck FL040-060 over the eastern terminals will
erode this evening, leaving only cirrus moving in from the west
on the front end of the TAF. Westerly winds less than 10kts
become light and variable as high pressure settles into the
region. Ceilings lower to FL045, but remain VFR as low pressure
passes to the south of the area. VFR
-SN possible at MFD/CAK briefly around the 18Z time frame but
chances far too low right now for mention in the TAF even as
TEMPO.
Outlook...Non-VFR expected in a widespread wintry mix of rain,
snow, sleet, and freezing rain late Wednesday afternoon through
Thursday. Non-VFR is likely to return in widespread rain and/or
snow on Saturday.
&&
.MARINE...
Winds over the lake through this evening will be out of the
southwest at 10-15 knots and tapering off overnight to less than 10
knots. Winds will stay below 10 knots until Wednesday morning when
the winds will shift out of the northeast at 10-15 knots. There will
be an increase in winds Wednesday afternoon ahead of a surface low
pressure system to over 20 knots. There will be a shift in the winds
to be predominant out of the west as the low pressure system moves
across the lake. There is the potential the winds could reach up to
30 knots in the open waters within this timeframe as there is a
tight pressure gradient across the region. Winds will diminish to
around 15 knots during the day on Friday. On Saturday, winds will
shift out of the south and be around 10 knots ahead of the next low
pressure system Saturday night.
Most of Lake Erie remains ice covered and waves will be limited in
ice-free areas. Small Craft Advisory issuance remains suspended
until further notice due to extensive ice cover.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Kahn
NEAR TERM...Kahn/26
SHORT TERM...23
LONG TERM...23
AVIATION...26
MARINE...23
Area Forecast Discussion
National Weather Service State College PA
1056 PM EST Mon Feb 10 2025
.SYNOPSIS...
High pressure will build across the Commonwealth tonight. A weak
area of low pressure will pass south of Pennsylvania late
Tuesday into Tuesday night spreading snow across the southern
third to half of the state. A more significant storm with a
mixed bag of precipitation is likely to track just west of the
state Wednesday night into early Thursday.
&&
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
High pressure building over PA will provide the area with fair
weather and light wind tonight. Mostly clear skies and light
wind will allow temps to tumble quickly this evening over much
of Central PA. However, readings should level off late at
night, as thickening high clouds arrive ahead of a wave of low
pressure lifting out of the Miss Valley. Expect min temps to
range from the mid teens over the N Mtns, to the mid 20s across
the Lower Susq Valley.
&&
.SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
A weak southern stream shortwave and associated surface low is
progged to track south of PA Tuesday evening. All guidance
indicates PA will be on the northern edge of the snow from
this system, with the strongest fgen forcing progged to pass
south of the Mason Dixon Line. Thermal profiles are cold enough
for all snow, but ensemble plumes support only light
accumulations with little spread amongst members. Most likely
accumulations Tue PM range from 2-3 inches south of the PA
Turnpike, to nothing over the N Mtns.
Latest model guidance indicates an arrival time of around noon
over the southern tier of the state, to around 5PM along the
I-80 corridor. Expect the snow to taper off around 06Z Wed, as
the shortwave and best forcing exit the state. However, a moist
easterly flow, combined with orographic forcing, is likely to
result in some very light lingering wintry precip over Southern
PA into midday Wednesday.
The focus Wed PM shifts to an upstream trough over the Plains
States. Guidance indicates the associated surface low will track
west of PA, combined with a blocking high over the Canadian
Maritimes. This scenario supports a wintry mix across Central PA
late Wed/Wed night with snow at onset, followed by sleet and
then freezing rain. EPS mean qpf is between 0.20 and 0.40
inches. Ice should linger the longest over the North Central
Mtns, but an eventual change to rain appears likely over most of
the forecast area overnight into Thursday morning, as the
surface low passes north of PA and low level cold air is scoured
out with the arrival of a trailing occluded front. As for wintry
precip totals, current mean qpf and sounding data supports a
light snow/sleet accum of 0.5 to 2 inches Wed evening, followed
by a light glaze of ice, with rising temps and improving travel
conditions toward the Thu AM commute.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Thursday looks mild and increasingly windy, as strengthening low
pressure passes north of the state and Central PA briefly
breaks into the warm sector ahead of the trailing cold front.
We are sticking with NBM max temps Thursday in the upper 30s to
upper 40s for now, but model soundings indicate the potential
of highs in the 50s with deep mixing and 850mb temps around 2C
just behind the front.
Scattered rain showers are likely to accompany the front, then
scattered lake-enhanced snow showers are possible over the W
Mtns toward evening. Will have to watch for the possibility of
locally damaging wind gusts along and behind the front Wed
afternoon. Bufkit soundings indicate the potential of gusts near
50kts associated with deep mixing behind the front.
Any lake-enhanced orographic snow showers over the W Mtns should
be light and diminish Thu night, as surface ridging and falling
inversion heights arrive.
All long term guidance supports broad high pressure moving over
PA Thursday night into Friday night. Mostly sunny skies, light
winds, and dry weather will persist with temperatures a few
degrees below normal.
By the weekend, another storm will approach the northeast,
though considerable uncertainty remains. Latest EPS and GEFS
both indicate phasing of a southern stream shortwave and the
northern branch of the jet stream over the Midwest early next
weekend, resulting in a strengthening surface low lifting
northeast out of the Miss Valley toward PA. The latest EPS mean
surface low track across Southeast PA, along with lack of a
blocking high to the northeast, would point to a mostly rain
event. However, there remains plenty of uncertainty inherent
in a day 5/6 forecast and a slight southward shift could result
in significant snow for parts of the area.
Although the specifics of next weekend`s storm remain
uncertain, there is greater certainty in blustery and cold
conditions arriving late Sunday into Monday, as the
strengthening surface low passes east of PA. Mean EPS 2m temps
currently support temps falling into the single digits Sunday
night over the NW Mtns, along with wind chills well below zero.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
High (80-90%) confidence in VFR conditions continuing overnight
with low-level dry air observed in multiple runs of RAP model
guidance; however, some potential exists for low-end VFR to
high-end MVFR cigs at JST/AOO in the near-term (through 04Z
Tuesday). Recent observations/Nighttime Microphysics imagery
does outline some low-level clouds at JST and in the vicinity of
AOO, but high confidence that these ceilings will continue to
decay late this evening and prevail VFR through much of the
overnight period with high pressure moving across central
Pennsylvania. Later in the overnight period (generally after
06Z Tuesday), the bulk of model guidance continues to indicate
high-level clouds streaming into the area with ceilings
gradually expected to lower throughout the morning/early
afternoon hours.
Model guidance continues to indicate ceilings and visibilities
falling across much of the area, starting off in the southwest
(JST/AOO) and overspreading north and east (IPT) as snow begins
to overspread much of the forecast area during the afternoon and
evening hours. Main restrictions with respect to ceilings and
visibilities are expected near/after 18Z Tuesday with moderate-
to-high confidence in IFR conditions south of the I-80 corridor
(JST/AOO ~90% confidence, MDT/LNS/UNV ~70% confidence, slightly
lower confidence on magnitude of restrictions) while lower
confidence exists further north on lower visibilities. Recent
RAP model guidance does indicate a higher signal for MVFR
conditions prevailing at IPT after 21Z, mainly based on
visibilities in snow. Given some continued model uncertainties,
have opted to indicate the last hour in the 00Z TAF package with
a PROB30 and lower visibilities in snow as snow is expected to
be approaching the airfield towards the end of the TAF package.
The main alternative solution at IPT is that slightly slower
progression of snow onset at the airfield allows for VFR
conditions to prevail, with BFD expected to prevail VFR
throughout the entire TAF package with moderate (~60%)
confidence.
Outlook...
Tue...Restrictions possible with snow, especially south of UNV.
Wed-Thu...Widespread restrictions likely with a mix of rain,
snow, sleet, and freezing rain. LLWS poss Wed night.
Fri...Restrictions poss in the west early, otherwise mainly VFR.
Sat...Widespread restrictions likely in a mix of rain, snow,
sleet, and freezing rain.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 11 AM Tuesday to 7 AM EST
Wednesday for PAZ033>035.
Winter Weather Advisory from 2 PM Tuesday to 7 AM EST
Wednesday for PAZ036-063>066.
&&
$$
SYNOPSIS...Lambert
NEAR TERM...Fitzgerald
SHORT TERM...Fitzgerald/Bauco
LONG TERM...Fitzgerald/Banghoff
AVIATION...NPB
Area Forecast Discussion
National Weather Service Wilmington OH
902 PM EST Mon Feb 10 2025
.SYNOPSIS...
A system will bring light snow to the region on Tuesday, with
the highest snowfall accumulations of several inches expected
along and south of the Ohio River. After this system, another
strong low pressure system will develop and bring rain and some
mixed precipitation Wednesday into Wednesday night. A third
system will bring some widespread precipitation back into the
Ohio Valley once again this weekend. Although temperatures will
oscillate up and down with the approach and passage of each
subsequent system, the overall trends will be for near normal to
slightly above normal temperatures through this weekend.
&&
.NEAR TERM /THROUGH TUESDAY/...
Focusing on the ILN Forecast area, trends from the 18Z-00Z runs
of the HRRR and RAP, along with an early look at the 00Z
NAM, suggest a slight southward trend in northern extent and a
slight downward trend in magnitude for snow amounts late tonight
into Tuesday. Additional adjustments will be considered after
the full 00Z model suite and probabilistic data is available,
but for this update, some slight southward/downward adjustments
were made to the going forecast. Not enough confidence with this
update to make any changes to headlines. This still results in
a 3-4 inch forecast across the southern tier of ILN counties,
with some higher amounts in Lewis County KY.
Current observations suggest that surface temperatures,
particularly across the southern half of the ILN CWA, are
running a couple degrees warmer than previously expected. This
has also been adjusted.
Previous discussion >
Skies have trended mostly clear today, although some cirrus
will continue to overspread the region through the evening,
with thickening cloud expected area-wide toward/beyond midnight.
Amidst plentiful sunshine, temps have climbed into the
mid/upper 30s (N) to lower/mid 40s (S) with light northerly
flow.
Most, if not all, of the near term period will be quiet as the
low pressure slowly organizes and approaches from the SW toward
daybreak Tuesday. Strengthening isentropic lift will promote the
development of banded snow, initially well to the SW of the ILN
FA, during the predawn hours Tuesday. This band should spread to
the NE through sunrise and beyond, moving into parts of the
Tri-State, northern Kentucky, and south-central OH during the
daytime.
Although there is going to be quite a bit of dry air in the LL
to erode on the leading edge of the pcpn, could very well see
some patchy SN make it to the ground in far SW parts of the
local area prior to daybreak, but do think that the most
impactful snow should hold off until near/after sunrise.
&&
.SHORT TERM /TUESDAY NIGHT/...
System 1 (of several) to impact the local area through the next
week will arrive Tuesday. As mentioned, strengthening
isentropic/WAA-induced ascent will promote a moistening of the
profile and the development and expansion of a band of snow to
the NE into the local area Tuesday morning. There is good
frontogenetical forcing, which will initiate a sufficient
overlap of lift/moisture within the DGZ, which should be fairly
deep, owing to the quasi-isothermal profile within the DGZ. This
will allow for some efficient dendrite growth and efficient
snow rates, especially mid/late morning across the SE quarter of
the ILN FA. This is when rates are expected to be the highest,
especially in N/NE KY and far srn OH, where rates could approach
1"/hr at times. Wet-bulbing should allow for air temps to be
dragged down to around the freezing mark, supporting colder
temps where the snow is the steadiest/heaviest.
There is likely to be fairly tight cutoff to the nrn fringe of
the snow, with limited impacts expected where the lower snow
rates are expected. In fact, with the exception of far SE parts
of the local area where higher rates are expected to persist for
longer, road impacts may be somewhat limited given the
(relatively) high sun angle and the fact that the snow will be
falling during the daytime amidst borderline (near freezing) air
temps. This should keep most accumulations confined to
elevated/grassy surfaces. This is not to say there won`t be
slick spots -- because there most certainly could be anywhere
snow accumulates, but the potential for snow covered roads is
certainly highest where the warning has been issued, stretching
from Owen Co KY to Scioto Co OH and points S of this axis.
Amounts will range from little to nothing (near/N of I-71) to
1-3" (from Switzerland Co IN to Hocking Co OH) to 3-5" (where
the warning resides). Where lighter amounts are favored, most
of the accumulation is likely to be confined to grassy/elevated
surfaces and accumulation efficiencies will be lower in these
areas.
Although the steadiest snow should subside late afternoon, patchy
light snow will linger a bit southeast of I-71 into the
evening. In fact, there are some indications as we approach/go
beyond midnight into Tuesday night, the patchy snow may
transition more to some patchy freezing rain, particularly from
N/NE KY into south-central OH, as the profile warms and we lose
saturation in the DGZ. It is for this reason that the
advisories/warnings are in effect until 12z Wednesday. The
potential for patchy freezing rain/drizzle Tuesday night could
translate into isolated slick spots, even though the accumulating
snow will be long over.
Highs Tuesday top out in the lower to mid 30s and lows Tuesday
night in the mid 20s (N) to lower 30s (near/S of OH Rvr).
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
System 2 (Wednesday-Wednesday night): At the onset of the long term
period, the second system will be quickly moving into the area as
the shortwave trough shifts northeastward into the Great Lakes and
Ohio Valley. Before the main moisture arrives, there is the
potential for freezing drizzle or light freezing rain Wednesday
morning ahead of the warm air surge. Forecast soundings indicate
warm air will advance aloft with surface temperatures a few degrees
below freezing. With daylight, any threat for slick conditions will
end as temperatures warm into the mid 30s for much of the area and
even lower 40s across the south. The area of concern for remaining
below freezing as the main moisture moves in during the afternoon is
across eastern Indiana and western Ohio.
The track of the low pressure into the eastern Indiana and western
Ohio eventually brings temperatures above freezing for all areas,
but not before the initial wave of moisture. As the warm front
shifts north Wednesday afternoon, precipitation increases in
coverage across the area, with surface temperatures still in the
upper 20s across the west and east. Travel impacts may be limited
due to the freezing rain occurring during the day, but some slicks
should be expected at the onset of the the freezing rain. Toward
evening, temperatures continue to climb above freezing, with rain
the favored precipitation type across the whole area.
Temperatures cool behind the pressure, but only a few flurries are
expected on the back side of the low pressure Thursday morning.
Flurries linger into Thursday afternoon as a weak shortwave pivots
through. Much cooler temperatures arrive Thursday night with values
in the single digits to teens.
Friday: High pressure provides a pause in precipitation across the
region with temperatures generally in the low 30s (north) to low
40s (south).
System 3 (Saturday-Sunday):
Most deterministic guidance suggests a broad warm air advection
regime ahead of the trough, with rain being the favored
precipitation type. The core (25th-75th percentile range) of the
ensemble guidance shows the snow remaining to the north with some
outlier members (specifically within the Canadian ensemble) showing
potential for snow accumulations further south.
Diagnosing the reasons for why the WAA regime is favored is due to
the trough axis failing to pivot and become negatively, or even
neutrally, tiled. With the positively sloped trough, warm air
advection spreads across the entire Ohio Valley, with cold air
advection occurring late. This would likely lead to a change over to
snow Sunday with limited accumulations. Flurries likely linger
Sunday night into Monday with cooler temperatures in place to start
the next work week.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
VFR conditions are expected through roughly the first 12-16
hours of the TAF period. Light easterly winds are expected, with
some mid level clouds, eventually lowering to VFR stratocumulus.
In the 12Z-16Z time frame, snow will spread into the region from
the south. As the snow moves in, aviation conditions will
gradually diminish, eventually ending up with IFR ceilings and
visibilities. Confidence is fairly high in IFR conditions for
most of the TAF sites, though confidence is only medium a KDAY,
which will be a little further to the northwest of the heavier
snow. Regardless, significant snow accumulations are not
expected at any of the TAF sites -- though IFR conditions still
appear likely.
Tomorrow evening, the snow will gradually end from west to east,
allowing visibilities to return to VFR. Ceilings may remain IFR
to MVFR for a while.
OUTLOOK...MVFR to IFR conditions may continue through Tuesday
night. MVFR to IFR conditions are expected again from Wednesday
afternoon through Thursday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Winter Weather Advisory from 4 AM Tuesday to 7 AM EST
Wednesday for OHZ073-074-078>080-082.
Winter Storm Warning from 4 AM Tuesday to 7 AM EST Wednesday
for OHZ081-088.
KY...Winter Weather Advisory from 4 AM Tuesday to 7 AM EST
Wednesday for KYZ089>093.
Winter Storm Warning from 4 AM Tuesday to 7 AM EST Wednesday
for KYZ094>100.
IN...Winter Weather Advisory from 4 AM Tuesday to 7 AM EST
Wednesday for INZ075-080.
&&
$$
SYNOPSIS...KC
NEAR TERM...KC/Hatzos
SHORT TERM...KC
LONG TERM...McGinnis
AVIATION...Hatzos
Area Forecast Discussion
National Weather Service North Platte NE
552 PM CST Mon Feb 10 2025
.KEY MESSAGES...
- Bitter cold temperatures tonight through Thursday morning.
- Potential for minor impacts from periods of light snow tonight
through Tuesday. Snowfall amounts will mainly be an inch or less.
- A more significant system will affect the area Tuesday night
into Wednesday. Snowfall amounts of 3 to 5 inches are
possible across portions of southwest and central Nebraska.
&&
.SYNOPSIS...
Issued at 253 AM CST Mon Feb 10 2025
A strong arctic front was currently located from near Ogallala
through Ord. Temperatures ranged from 12 at Gordon to 38 at
Imperial. Light snow was reported across portions of northern
and northeast Nebraska, including Gordon and O`Neill.
&&
.SHORT TERM /THROUGH TUESDAY/...
Issued at 253 PM CST Mon Feb 10 2025
A deep upper low is currently centered over Hudson Bay Canada with
an upper trough extending southwestward across the Northern Plains
into the Pacific Northwest. This upper trough will sag slowly
southward tonight as a northern stream 300mb jet axis develops from
Wyoming across South Dakota into the northern Great Lakes. A strong
arctic front will push through trough the remainder of southwest
Nebraska early this evening. Will see the atmospheric column
saturate from H8 to H6, as the low levels will still have some dry
air to overcome. Some weak lift at times in the dendritic layer will
produce some very light snow. Snow accumulations across the area
from a dusting to a few tenths of an inch possible. On Tuesday, the
main upper trough axis will move into the Central Rockies. This will
bring increasing chances downstream into western Nebraska. Light
snow accumulations up to a half inch are expected mainly south of
Highway 2 during the afternoon, with likely to categorical POPs by
late afternoon. Tonight will be bitterly cold from 4 below to 4
above. Lowest wind chills from 10 below to near 15 below with a
northeast wind 10 to 15 mph. Highs Tuesday very cold from the upper
single digits northeast to low to mid teens southwest.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 253 PM CST Mon Feb 10 2025
A more significant system arrives Tuesday night into Wednesday
and will bring the potential for moderate snow accumulations.
The main upper trough axis will move across Nebraska and Kansas
Tuesday night into Wednesday. A coupled 300mb jet is indicated by
the GFS. The northern jet axis will extend across northern Nebraska
across southern Minnesota into the northern Great Lakes, while the
southern jet axis will extend from southwest Texas across southeast
Oklahoma and southeast Missouri. This will provide an area of upper
level divergence across Kansas and southern Nebraska. While PWATs
will be modest from a quarter to a third of an inch across southern
Nebraska, SLRs will be highs near 20 to 1. Forecast snowfall amounts
will be near 3 inches along an Ogallala through Burwell line, with
higher amounts from 3 to 5 inches to the south. The GFS and ECMWF
showed a slight trend lower in QPFs the past few runs, so confidence
in higher amounts is less. Mesoscale models however, including the
HRRR and NAM 3km favor higher amounts. Snowfall rates up to a half
inc per hour area possible later Tuesday night into Wednesday
morning. Bufkit soundings indicate very weak winds throughout
the dendritic layer, so dendrites are unlikely to break apart
and should remain fluffy. While no highlights are currently in
effect across western and north central Nebraska, will be
considering highlights with the next forecast shift. The snow
will quickly end Wednesday afternoon.
Very cold Tuesday night, with lows near zero. Winds winds light and
variable or very light northeast, wind chills from zero to 10 below
expected. Very cold Wednesday with highs from 12 to 17 above. With
clearing skies Wednesday night, lows from 5 below to around 10
below. With a light southwest wind increasing overnight into
Thursday morning, wind chills around 15 below, possibly 20 below are
possible.
Dry conditions Wednesday night through Thursday night as a deep
upper trough moves into the Western U.S. and upper ridging builds
into the region.
Another chance for snow Friday night into Saturday, mainly across
southern Nebraska, as an upper trough crosses the region. This looks
to be a quick moving system with snowfall amounts fairly light.
Highs next Thursday are forecast to moderate to the mid 20s to low
30s and 30s Friday. Turning colder Saturday in the teens to near
20 and mid teens to upper 20s Sunday.
Warmer Monday, as surface high pressure moves into the Ohio Valley
and highs warm into the upper 30s to low 40s west.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 552 PM CST Mon Feb 10 2025
The main aviation concern will be increasing snow chances across the
region starting Tuesday. Snow will move into southwest Nebraska and
overspread the region Tuesday afternoon. Best potential to see
significant snowfall will be south of Highway 2 impacting KLBF.
Expect reduced visibility, snow covered runways, and slippery
surfaces. Accumulations of 6 inches or more of snowfall is possible
south of I-80 with locally higher amounts in banded snowfall. The
majority of the snowfall will occur after 00Z Wednesday before
ending late Wednesday morning.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Roberg
SHORT TERM...Roberg
LONG TERM...Roberg
AVIATION...Kulik
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
956 PM CST Mon Feb 10 2025
.KEY MESSAGES...
- Intermittent flurries with a chance for a period of light
accumulating snow late tonight into Tuesday morning, primarily
near and north of I-80. Flurries may continue near the lake
through the day on Tuesday.
- Winter storm will impact the area Wednesday and Wednesday
night with snow, heavy at times, including during the
afternoon/evening commute.
- Very cold Thursday into Friday with subzero lows expected
Thursday night many areas.
- Another winter storm could impact the region late Friday into
the first half of the weekend.
&&
.UPDATE...
Issued at 956 PM CST Mon Feb 10 2025
No changes of note were made to the going forecast regarding
the snowfall potential for tonight into Tuesday.
Recent HRRR and RAP runs have trended a little more favorably
towards light snowfall occurring overnight tonight into Tuesday
morning, favoring slightly stronger, though still transient,
mid-level frontogenesis that would yield better omega and mid-
level saturation intersecting the dendritic growth zone. Even
with this though, full saturation of any section of the
tropospheric column may still not quite be achieved, and the
modest degree of forcing may still not be enough to fully erode
the dry low-level air beneath the cloud layer and allow for
snow to fall at a steady enough clip to accumulate much, if at
all.
Thus, continuing with an intermittent flurry mention across
the entirety of our forecast area overnight into Tuesday
morning and keeping some slight chance and low-end chance PoPs
(up to 30%) for accumulating snow in our forecast grids still
seems like the way to go. Opted to keep the mentionable PoPs as
is in the northern half of our forecast area as this is where
the mid-level UVV signal is most pronounced in most of the 00Z
hi-res guidance suite, though an argument could be made for the
southward expansion of these lower-end PoPs given that hi-res
guidance often struggles with the placement of these relatively
subtle frontogenetical circulations -- even at very short time
ranges just a few hours out.
Ogorek
&&
.DISCUSSION...
Issued at 236 PM CST Mon Feb 10 2025
Through Tuesday Night:
Our region will remain beneath fast westerly flow aloft
tonight, with a strong positive-tilt mid-level short wave
tracking north of the region across the upper Midwest, northern
Great Lakes and Ontario. Additional sheared mid-level energy will
zip from the Plains to the mid-Mississippi Valley through early
Tuesday. The local area will be split by stronger forcing to the
north and better low-mid level baroclinicity to the south.
However, weak warm advection and isentropic ascent response and
associated transient frontogenesis is depicted in model guidance
to develop from IA into southern WI and the northern Illinois
late tonight into early Tuesday, which will likely increase
saturation for a time.
Forecast soundings depict some potential for light snow after
midnight through mid morning primarily near and north of I-80
across northern IL. Despite modest forcing and fairly limited
moisture, suspect that some of the drier guidance (including
extended HRRR runs in particular) is not eroding the low-level
dry air enough. The guidance with sufficient saturation (ie. NAMs,
RAP, ECMWF) suggests transient bands of snow coming down at a
steady clip. With that said, it`s still uncertain exactly where
the dry air will be eroded enough to support a period of light
accumulating snow and reduced visibility (amidst otherwise non-
accumulating flurries). Thus, kept PoPs in the low chance range
(~30%) near/north of I-80, and slight chance (~20%) down to a bit
south of I-80.
Due to the short duration, modest forcing, and limited moisture
availability, it still looks like snow accumulations (if/where
they occurs) would be no more than coating to a few tenths/locally
to one half inch. Surface temps will be in the upper teens-mid
20s however, which would allow for the potential light
accumulation to coat paved surfaces and cause some travel
impacts into the AM commute. Farther south/east, flurries are
more likely where forcing and saturation is less impressive.
Low level winds will shift northeast later Tuesday morning, which
may support some relatively weak lake-effect snow showers and
flurries into parts of northeast IL/northwest IN during the day.
Lake-induced thermodynamic parameters appear pretty marginal, with
inversion heights only around 5 kft suggesting fairly poor-
quality snow. Several CAMs continue to produce some light QPF into
the afternoon from Lake and Cook IL into Lake (IN) and northwest
Porter counties, and have maintained some low-chance pops (20%)
for lake snow showers with a dusting to a couple of tenths of an
inch accumulation. Flurries may occur downwind into the
I-65/57/55 corridors, though am not expecting any accumulations
too far away from the lake, and withheld any formal snow accums
even near the lake during the afternoon hours.
As low-level winds become more easterly Tuesday evening, light
lake effect snow and flurries should focus into northeast
Illinois. Finally, initial bands of (mainly light) snow from
our impending winter storm system may develop eastward in the
pre-dawn hours. We included a corridor of low chance (~30%)
PoPs primarily for areas northwest of I-55. By far the more
consequential snow and impacts will arrive later Wednesday
morning and beyond, detailed in depth in the rest of the
discussion (below).
Castro/Ratzer
Wednesday through Monday:
Vigorous shortwave trough just offshore British Columbia is
progged to dig south into the Four Corners region tomorrow
(Tuesday) afternoon before ejecting northeast across the Plains
and into the Midwest Wednesday. Surface cyclogenesis will take
place over the lower Ohio Valley Wednesday in response to this
approaching trough. This low will then track northeast across
the Ohio Valley. For the first time this winter, there will be
ample cold air in place for an expansive shield of snow to
develop on the cold side of this system.
There has been a bit of a northwest jog in the track of this
system in this morning`s guidance, most notably in the NAM.
Often times in strong warm air advection regimes, the NAM ends
up being closest to reality with how far north the snow/mix/rain
line gets, so did lean a bit more toward the NAM solution
bringing some freezing rain and sleet north into our far
southern and southeastern CWA.
Strengthening low and particularly mid level warm air
advection/isentropic ascent will couple with strong upper level
divergence, first in the entrance region of departing 130-140kt
upper level jet stream, then in the left entrance region of a
second jetlet poking into the area late in the afternoon and
into the evening. Fairly strong isentropic ascent coupled with
the strong upper level divergence should result in a 6-8 hour
period of deep, strong ascent, focused on Wednesday afternoon
and evening. Guidance shows a fairly impressive northward surge
of moisture, with precipitable water values of around 150% of
normal Wednesday afternoon, which coupled with the deep, strong
omega should result in some fairly heavy snowfall.
Unfortunately, as far as amounts go, there remains uncertainty
in regards to specific totals. The uncertainty is driven largely
by the questions in regards to the snow:liquid ratios (SLRs),
with climo for southwest originating storms and the Cobb method
both favoring SLRs closer to 10 to 11:1. NBM guidance is
substantially higher, closer to 14-18:1, highest northwest CWA.
For this forecast have split the difference between the 2
extremes, though forecast soundings (particularly in the warmer
NAM) show a fairly deep isothermal layer closer to the -5C with
the heavier precip, which would tend to favor more aggregates
and lower SLRs.
Regardless of the exact SLRs and snowfall totals, it looks to be
a very impactful storm with heavy snowfall rates coinciding with
the afternoon commute. There is an at least 50% chance of 6"+
totals, which coupled with the expected impacts, justifies a
Winter Storm Watch. If SLRs end up higher or if there`s some
modest lake enhancement, some totals over 8" are certainly not
out of the question. Snow will probably mix with/change to
sleet/freezing rain in the southeastern CWA late Wednesday
afternoon into the evening (with uncertainty on how far north
the mix line will reach). This will likely cut down on snowfall
totals, but obviously sleet and freezing rain would result in
travel issues of their own.
Precipitation rates should taper later Wednesday evening into
the overnight, so the Thursday morning commute should be much
improved vs. Wednesday PM. A couple days of below normal temps
are then expected. Temps Thursday could be steady or even fall
a degree or two in the afternoon, likely mostly in the teens.
Fresh snow cover and a 1040mb high in the area Thursday night
should set the stage for subzero low temps across most of the
area. The 12z guidance has trended colder with temps Friday,
which if this trend continues with the 00z guidance, temps for
Friday will need to be lowered.
Another storm system could bring more wintry precipitation to
the region late Friday into at least the first half of the
weekend. There`s a good deal of spread still with this system
and there are lot of moving pieces, leading to higher
uncertainty with how much/if there is phasing. Given the
uncertainties at this distance, made no changes to NBM grids.
Another shot of very cold air is expected in the wake of that
system late in the week into early next weekend.
- Izzi
&&
.AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 600 PM CST Mon Feb 10 2025
Main concerns:
- Intermittent flurries with a 30% chance for a period of light
accumulating snow late tonight into Tuesday morning.
- MVFR ceilings and flurries may continue near the lake through
the day on Tuesday.
Light and variable winds are expected this evening, eventually
turning northerly and increasing overnight. Directions trend
east northeasterly by Tuesday morning around 12 kt.
Confidence in a dusting of snow occurring along with VSBY and
CIG reductions remains low for late tonight into Tuesday
morning. Opted to maintain PROB30 groups during in the 9-14Z
timeframe with this update, earliest at RFD. This will
ultimately depend on whether dry air in the low-levels can be
overcome.
MVFR stratus is then expected to move in off the lake Tuesday
morning across the Chicago metro terminals. Expect at least
intermittent flurries to occur beneath this stratus deck for
much of the day at ORD/MDW/GYY. While little to no accumulation
is currently expected, an additional localized dusting of
0.1-0.2" can`t be ruled out.
Petr
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Winter Storm Watch from Wednesday morning through late
Wednesday night for ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ019-ILZ020-ILZ021-ILZ023-
ILZ032-ILZ103-ILZ104-ILZ105-ILZ106-ILZ107-ILZ108.
IN...Winter Storm Watch from Wednesday morning through late
Wednesday night for INZ001-INZ002.
LM...None.
&&
$$
Visit us at weather.gov/chicago
Area Forecast Discussion
National Weather Service Marquette MI
657 PM EST Mon Feb 10 2025
.KEY MESSAGES...
- Light to moderate lake effect snow persists in the west wind
snowbelts this evening.
- A cold front will kick lake effect snow to the WNW wind
snowbelts overnight. Heavy lake effect snow will develop north
of M-28 in Luce county, where a Winter Weather Advisory is in
effect through Tuesday morning.
- Mainly below normal temperatures are expected this week.
Single digit highs on Tuesday with lows down to -20F by
Wednesday morning in the west.
&&
.UPDATE...
Issued at 528 PM EST Mon Feb 10 2025
Water vapor imagery and RAP analysis show a shortwave extending from
northern Ontario across nw MN into ND. Shuniah radar from just
outside of Thunder Bay, ON shows LES increasing over nw Lake
Superior in response to the forcing from the approaching shortwave
and the resulting lifting of inversion. Winds are slightly backing
ahead of the wave over the southern portion of western Lake
Superior. This is leading to low-level flow once again becoming more
convergent as wnw flow remains over the northern portion of western
Lake Superior. Latest NAMnest/RAP show a healthy increase in
convergence across the Keweenaw over the next few hrs and that will
support increasing LES intensity. Winds then veer with passage of
shortwave, sending a slowly weakening convergence zone southward
during the night and allowing LES to diminish across the Keweenaw.
Winds will also increase further across the Keweenaw over the next
few hrs, peaking roughly 23-02z, and that will lead to more
blsn/more frequent poor vis. Updated forecast extends northern
Houghton County advy to midnight, and Keweenaw County was added to
the advy. Snow accumulations from 5pm to midnight should range from
2-4 inches with isolated 5-6.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 255 PM EST Mon Feb 10 2025
RAP analysis and GOES satellite imagery this afternoon reveal mostly
clear skies across the interior, while west wind lake effect snow
persists in the Keweenaw and far northeast UP. Though not too
discernible on water vapor channels, a positively tilted mid-level
shortwave is currently diving southeast over northern Ontario.
Through the rest of the evening, west wind lake effect snow will
persist, taking aim in northern Houghton and Keweenaw Counties, as
well as far northern Luce and Chippewa. Convergent banding off of
the Bayfield Peninsula into the Keweenaw will allow lake-induced
inversions to rise to near 7-10kft however a short 1-2kft DGZ will
limit snow growth. Thus, opted to let the current Winter Weather
Advisory for N Houghton County expire at 00z (7pm est). An
additional 2-4" of fluffy LES should still be expected in the
Keweenaw through Tuesday morning.
A west-east oriented dominant LES band is beginning to take shape
just off the central UP shoreline, taking aim at far NE Alger County
and northern Luce county. CAM guidance show the band wobbling
slightly north and south, but persisting over these areas through
the evening. With model soundings indicating similar inversion
heights between 7-9kft and strong lift within a 3-4kft deep DGZ,
moderate to heavy lake effect snow will persist north of M-28.
Later this evening the aforementioned shortwave continues southeast
over the Upper Great Lakes, dragging a cold front across Lake
Superior and briefly veering winds to the WNW to NW wind
snowbelts. The reinforcing shot of cold 850mb temps around -23
to -26C behind the front develop lake induced troughing and
convergence in the far eastern lake, focusing a heavy convergent
band somewhere along the Luce/Chippewa county line. There is
still uncertainty in the exact location of the band, as model
guidance hasn`t been kind to us in LES band placement over the
last 24-36 hours in the west... Regardless, in coordination with
our friends at WFO Gaylord, a Winter Weather Advisory has been
issued for Luce and Chippewa counties tonight, where upwards of
5-10" is expected north of M-28 through Tuesday morning,
however, locally higher amounts are possible where the band
persists. Recent HREF guidance suggests a 30-50% chance of
1"/hr snowfall rates west of Whitefish Point around sunrise.
Elsewhere, expect mostly clear skies. Temperatures will drop
below zero for much of the interior tonight, potentially
reaching as low as -10 to -15 for the typical cold spots.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 223 PM EST Mon Feb 10 2025
Upper air pattern consists of a trough in the western U.S. 12z Tue
with a shortwave over the northern Rockies. Troughing moves into the
Rockies 12z Wed and into the plains 00z Thu and into the upper Great
Lakes 12z Thu. Lake effect snow showers continue Tue into Tue night
in west wind snow belts and then a system approaches from the south
and sideswipes the area later Wednesday into Wednesday night with
lake effect snow again for Thursday. Temperatures stay below normal
for this forecast period. In fact, temperatures could drop to -20F
Wednesday morning in the interior west.
In the extended, the GFS and ECMWF show a 500 mb trough in the
western U.S. and a trough in the eastern U.S. 12z Fri. Troughing
then moves into the Rockies and northern plains 12z Sat. This trough
then moves into the central U.S. 12z Sun with a strong surface
pressure gradient over the upper Great Lakes. The area is still
embedded in a deep trough 12z Mon. Temperatures stay below normal
for this forecast period.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 656 PM EST Mon Feb 10 2025
Disturbance passing across the area will give a boost to westerly
flow lake effect snow showers this evening at CMX. Expect LIFR to
prevail for much of the evening, including conditions occasionally
blo airfield landing mins thru at least 02z due to shsn/blsn under
winds gusting to 25-30kt. With passage of disturbance and veering of
winds, conditions will improve to IFR for the overnight. IFR should
then largely prevail at CMX until later Tue aftn when improvement to
MVFR should occur. At IWD, wind direction won`t be favorable for
lake effect shsn, but as winds veer a little overnight, VFR should
give way to a period of MVFR cigs along with some flurries. VFR
should then prevail at IWD late tonight thru Tue. At SAW, wind
direction also won`t be favorable of lake effect shsn. Expect VFR to
prevail thru the fcst period. Some flurries will be possible
overnight.
&&
.MARINE...
Issued at 223 PM EST Mon Feb 10 2025
Northwest winds of 20-30 kts continue tonight with some gale force
gusts to 35 kts expected, mainly over the east half of the lake for
a few hours this evening into tonight. Winds fall to around 20 kts
Tuesday morning, backing west by Tuesday evening as they settle
below 20 kts. Southwest winds less than 20 kts are expected on
Wednesday. A cold front on Thursday brings back northwest winds of
15-30 kts on Friday and increase to north to 30 knots on Saturday.
Freezing spray continues across the lake through Tuesday morning.
Hoisted a Heavy Freezing Spray Warning for late this afternoon
through tonight.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Weather Advisory until midnight EST tonight for MIZ001-
003.
Winter Weather Advisory until 7 AM EST Tuesday for MIZ007.
Lake Superior...
Heavy Freezing Spray Warning until 1 AM EST /midnight CST/
Tuesday for LSZ162.
Heavy Freezing Spray Warning until 7 AM EST /6 AM CST/ Tuesday
for LSZ240>244-248>251-263>267.
Lake Michigan...
None.
&&
$$
UPDATE...Rolfson
SHORT TERM...BW
LONG TERM...07
AVIATION...Rolfson
MARINE...07
Area Forecast Discussion
National Weather Service Morristown TN
840 PM EST Mon Feb 10 2025
...New UPDATE...
.UPDATE...
Issued at 755 PM EST Mon Feb 10 2025
Evening update mainly bumped up timing of incoming PoPs out of
Middle TN and AL as the initial upper divergence appears to be
effective at producing showers. Surface observations are showing
that there is still drier air near the surface which will need to
be overcome before rain starts accumulating. Outside of bumped up
PoP timing, the overall forecast remains on track and the
previous discussion and Key Messages are valid.
&&
.SHORT TERM...
(This evening through Tuesday)
Issued at 324 PM EST Mon Feb 10 2025
Key Messages:
1. Light rain expected to blossom over northeastern portions of
Tennessee after midnight tonight, with steadier rainfall arriving
around and after noon for the whole area tomorrow. Small streams
will begin to rise and rainfall will set the stage for increasing
flood risks.
2. A light wintry mix will occur over portions of far northeastern
Tennessee into southwest Virginia tomorrow morning. A winter weather
advisory is in effect.
3. Strong wind gusts possible overnight, especially in the foothills
of Greene County.
4. A Flood Watch is in effect from Tuesday afternoon through
Thursday morning, additional rain falling in the Long Term portion
of the forecast may cause flooding issues.
Discussion:
Nice weather thus far today, much of the clouds across the area have
already been scoured away. I could see high mares tail type cirrus
outside, indicative of incoming weather. Cloud cover will soon
return, unfortunately. A digging trough out west will help fan the
upper jet north of us to 150 knots, and help spur widespread upper
divergence overnight. This will help drive isentropic lifting and
bring precipitation to the area, especially across northern areas
of Tennessee into southwest Virginia. High resolution model
soundings indicate a snow transitioning to wintry mix
transitioning eventually to rain over the far northeastern parts
of Tennessee and southwestern Virginia. The winter weather
advisory in effect now covers the amounts and timing pretty well.
Warm air advection will bring an end to the wintry mix and an all
rain result by or near noon tomorrow.
HREF is insistent on wind gusts of 40 to 45 mph affecting Camp Creek
and nearby locations overnight into tomorrow morning. This would
normally be a surprise given weak winds aloft (only 15 to 20 knots)
but the presence of cold air damming on the Carolinas side will
likely drive a mild density gradient. This in turn helps spur wind
gusts to spill across the gradient as the atmosphere seeks balance.
Camp Creek tends to experience strong wind gusts in these setups,
especially with winter weather products out to the east of the
mountains.
Heading into the early afternoon hours tomorrow, the main shield of
rain should be moving and grooving into all of East Tennessee and
surrounding locales. HRRR depicts pretty steady rainfall, which will
serve to saturate the soils and prime everyone for flooding risks
later on. PWAT values will be around or above the 90th percentile,
so pretty soggy day, but the low level inversion present through the
daytime and saturated sounding precludes any risk of thunder
exacerbating rain rates.
&&
.LONG TERM...
(Tuesday night through next Monday)
Issued at 324 PM EST Mon Feb 10 2025
Key Messages:
1. Flood potential for Tuesday night through Thursday morning.
Rainfall of 2 to 4 inches with heavier amounts. Greatest
accumulation is expected across southeast Tennessee and southwest
North Carolina with this system.
2. Second strong storm system expected Saturday into Sunday with an
additional 2 to 4 inches with locally heavier amounts. The expected
heavy rain early this week combined with the additional heavy
rainfall will produce a significant flooding threat for this
weekend.
3. A period of gusty winds is expected across the mountains and
adjacent foothills Wednesday night and Saturday. With saturated
soils, downed trees and utility poles are likely to be more frequent
than is typical.
Discussion:
Very active extended period with heightened threat of significant
flash flooding this week into the weekend.
For Tuesday through Thursday morning, broad upper divergence across
the region will enhanced frontal-genetic forcing across the area.
Initially the strong forcing will be across the northern Plateau
into southwest Virginia, then become established over the much of
the east Tennessee and southwest North Carolina for the 36-48 hour
period. NAEFS QPF M-Climate and EFI shows a fairly high risk of
heavy rainfall over the region. NAEFS anomaly is showing good
850mb moisture transport as well as high PWs. Bulk of
precipitation will gradually come to an end mid-late Thursday
morning.
For Thursday afternoon through much of Friday night, frontal
boundary will move south with surface ridging and drier air. A
drier period is expected.
For late Friday night, Saturday, and Sunday morning, a stronger
upper jet and associated fronto-genetic forcing and isentropic lift
will produce another round of heavy rainfall. A strong low-level jet
will pull abundant moisture and warmer boundary temperatures into
the southern Appalachians. Good warm rain process is expected which
will enhance rainfall rates. NAEFS and EFI once again show a
stronger signal of abnormally heavy rainfall and 850mb moisture
transport and high PWs. Flash flooding will be a major concern for
this weekend as the recent rains and additional heavy rains may
produce significant flooding threat.
Additionally, southwesterly H85 flow near 50kts will promote gusty
winds in excess of 40mph across the mountains and adjacent foothills
of east Tennessee Wednesday night and again Saturday. With saturated
soils the threat for downed trees and powerlines will likely be
greater than typical with lower end wind events.
&&
.AVIATION...
(00Z TAFS)
Issued at 605 PM EST Mon Feb 10 2025
Extremely wet period begins this evening with incoming showers
expected spread across east Tennessee tonight. Initial rainfall
will be lighter, likely dropping flight categories down to MVFR or
IFR with more isolated showers. More widespread precipitation is
expected overnight, and with very humid air mass, the ceilings and
visibilities are both expected to drop quickly overnight with any
rainfall. Once categories drop to MVFR or lower it will be
difficult to climb back to VFR conditions, even without any
rainfall.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 44 49 45 55 / 40 100 100 100
Knoxville McGhee Tyson Airport, TN 39 45 43 55 / 60 100 100 100
Oak Ridge, TN 36 44 42 54 / 80 100 100 100
Tri Cities Airport, TN 34 42 40 50 / 80 100 100 100
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...Flood Watch from Tuesday afternoon through Thursday morning for
Cherokee-Clay.
TN...Flood Watch from Tuesday afternoon through Thursday morning 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.
Winter Weather Advisory from 3 AM to noon EST Tuesday for
Johnson-Southeast Carter.
VA...Flood Watch from Tuesday afternoon through Thursday morning for
Lee-Russell-Scott VA-Washington VA-Wise.
Winter Weather Advisory from 3 AM to noon EST Tuesday for Lee-
Russell-Scott VA-Washington VA-Wise.
&&
$$
SHORT TERM...
LONG TERM....DH
AVIATION...
AREA FORECAST DISCUSSION
National Weather Service Charleston WV
1036 PM EST Mon Feb 10 2025
.SYNOPSIS...
High pressure brings a calm before the storms into tonight.
Significant winter storm on Tuesday, with heavy rain far south.
Additional snow and flooding concerns round out the week.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 1030 PM Monday...
The latest HRRR and RAP models have pushed the heavier amounts
of snow line further south but thinking this will not change
much only snow amounts might vary slightly away from the
forecast. However, the main trough axis still looks to be in
place, therefore the heaviest snow should be along and to the
north of this feature. Neighboring offices may do some tweaking
to their headlines but at this point elected to not change
anything yet and will tell the oncoming shift to re-evaluate
with newer model guidance. The main point is that further south
may get a little more snow than anticipated, but for now kept
the totals as is.
As of 515 PM Monday...
Temperatures were adjusted slightly to account for the forecast
dropping them down a little too fast. Otherwise the forecast
remains on track.
As of 255 PM Monday...
Issued a Winter Storm Warning for much of the forecast area,
similar to the Winter Storm Watch area, making most of the
Warning an upgrade from the Watch. This is for snow Tuesday and
Tuesday night, and, in the mountains, freezing rain as well
Tuesday night into Wednesday morning. We are looking at 3 to 6
inches snowfall, except 6 to 9 in the higher mountainous
terrain, most of it occurring on Tuesday, and one to two tenths
of an inch of ice in the central mountains, mainly Tuesday
night.
Issued Winter Weather Advisories for mainly snow, on the
northern and southern fringes of the Warning, for 1 to 4 inches
snow across the northern tier, mainly Tuesday, and 1 to 3
inches in the far south, across southwest Virginia and along
part of the Tug Fork, mainly Tuesday morning.
Issued a Flood Watch for this system for southwest Virginia and
the southern coal fields of WV for Tuesday afternoon through
Tuesday night.
As of 130 PM Monday...
A snowstorm will impact much of the area on Tuesday.
High pressure sailing across the area this evening retreats
swiftly tonight, allowing a low pressure system to approach the
area on Tuesday. In the warm advection ahead of this system
Tuesday, a southwest-northeast oriented low level trough axis
develops along the mountains, with warmer air working into
southern portions of the area Tuesday morning.
Forecast soundings become isothermal near 0 C across central to
southern portions of the area Tuesday afternoon, and, depending
upon where west-northwest to east-southeast oriented
frontogenetic banding sets up and moves north-northeast,
precipitation could be heavy along a rain snow transition axis
shifting northward Tuesday during the late morning and
afternoon. A heavy warm advection thump of snow is possible
Tuesday morning into Tuesday afternoon, shifting northward from
southern to central portions of the area, and even into
northeastern portions of the area.
Temperatures will drop below freezing across the area tonight,
and then slowly climb above freezing from south to north across
southern and central portions of the area Tuesday afternoon,
and wind up around freezing even north.
Confidence is increasing in Watch/Warning criteria snowfall in
much of the Winter Storm Watch Area, with advisory criteria
around the northern and southern fringes.
Finally, quantitative precipitation amounts will be highest
farthest south, where another band of frontogenetic banding
sets up, this time oriented southwest to northeast along the
inverted trough axis. Precipitation amounts there could reach
an inch by Tuesday evening, much of it taking the form of rain,
and this could lead to stream rises and associated high water
issues from excessive runoff.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 130 PM Monday...
Initial disturbance and precipitation will move east of the area
late Tuesday night into early Wednesday, with a period of a wintry
mix expected, even across the lowlands. This will be followed by
another potent low that will eject northeast out of the southern
U.S. towards the area, transporting anomalously high PW air back
into the region. Heaviest precipitation during this period looks to
generally occur east of the Ohio River, with hydro concerns
expected, particularly across these areas where soils are already
saturated and creeks and streams are running high. Area is outlooked
in a marginal risk for excessive rainfall on Wednesday, mainly
across aforementioned areas. Although precipitation will be in the
form of rain across much of the area during the day Wednesday, parts
of the northern mountains could see periods of sleet or freezing
rain continuing during the day on Wednesday and Wednesday
evening/night as warmer air overruns colder temperatures at the
surface. Looking possible that these areas will need extended in
time on the winter storm warning headlines, but will hold off for
now until there is better certainty. In addition, gusty winds are
expected to develop during the period, particularly across eastern
zones/mountains. This along with the saturated ground will likely
lead to tree damage issues.
The low will continue to move north and east of the area Wednesday
night into Thursday, with decreasing precipitation as it does so,
and a cold front eventually sweeping across the area, along with
falling temperatures expected during the day Thursday. Northwesterly
flow developing behind the departing system will result in a
potential period of light upslope snow developing late Thursday
night, depending on how much moisture remains.&&
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 132 PM Monday...
Light upslope showers will occur Thursday evening, but will taper
off as high pressure nudges in from the west, providing a brief
break in the precipitation for Friday. Yet another potent low will
develop and move northeast into the area over the weekend, creating
the potential for heavy rains once again, and a renewed threat for
widespread hydro concerns. As the low departs later Sunday into
Monday, colder air will filter into the region, with precipitation
transitioning to snow area wide.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
As of 630 PM Monday...
A SNOWSTORM WILL IMPACT MUCH OF THE AREA ON TUESDAY...
All site are forecast to be VFR until the snowstorm pushes in
precipitation from south to north by mid morning. Thereafter,
the cloud decks will thicken and decrease in height with all
sites going IFR by the early to mid afternoon. Mainly VIS
restrictions throughout the afternoon as some snow will be heavy
at times. CIGs will start to drop to IFR or below by mid to
late afternoon lasting through this period. A mix of rain and
snow will get into some sites during the late afternoon with
even some freezing rain at BKW. Winds will be out of the east-
southeast mainly with no gusts expected other than at BKW where
winds will remain elevated through this period.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: Medium to high.
ALTERNATE SCENARIOS: Timing of onset of snow Tuesday morning may
vary. VIS restrictions may become lower under heavier
precipitation during the afternoon.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 02/11/25
UTC 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
EST 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H H H H H H H H H H M M
HTS CONSISTENCY H H H H H H H H H M L M
BKW CONSISTENCY H H H H H H H M M H L L
EKN CONSISTENCY H H H H H H H H H H H M
PKB CONSISTENCY H H H H H H H H H H H M
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z WEDNESDAY...
Widespread IFR likely Tuesday evening through Tuesday night in
areas of snow, rain and, in the mountains Tuesday night, even
freezing rain. IFR possible in mainly rain Wednesday afternoon
and night.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...Winter Storm Warning from 4 AM Tuesday to 11 AM EST Wednesday
for WVZ005>009-013>019-025>030-033-034-039-040-515>526.
Winter Weather Advisory from 4 AM Tuesday to 11 AM EST
Wednesday for WVZ010-011-020-031-032.
Winter Weather Advisory from 4 AM to 7 PM EST Tuesday for
WVZ024.
Flood Watch from Tuesday afternoon through Wednesday morning
for WVZ024-025-033-034.
OH...Winter Storm Warning from 4 AM Tuesday to 11 AM EST Wednesday
for OHZ085>087.
Winter Weather Advisory from 4 AM Tuesday to 11 AM EST
Wednesday for OHZ066-067-075-076-083-084.
KY...Winter Storm Warning from 4 AM Tuesday to 11 AM EST Wednesday
for KYZ101>103-105.
VA...Winter Weather Advisory from 4 AM to 7 PM EST Tuesday for
VAZ003-004.
Flood Watch from Tuesday afternoon through Wednesday morning
for VAZ003-004.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM/JZ
SHORT TERM...SL
LONG TERM...SL
AVIATION...JZ