1/24-1/25 Major Winter Storm - S. IL, IN, and OH

[King James]

It’s not much but it’s starting to dust up the cars. Better than just 30 minutes ago

[Stevo6899]

30 minutes ago, Radtechwxman said:

Can we maybe get back on topic and stop the childish arguing? 

Just some harmless entertainment between model runs. I think most places are locked and loaded on a great storm. Gonna be fun tracking this one from afar for the detroit area.

[Stevo6899]

26 minutes ago, AWMT30 said:

Incoming Hit on SE Michigan on the 18z HRRR 

Not gonna lie rap/hrr more than 12 hours out is just as useless as looking at the nam at all.

[Radtechwxman]

Got some flurries here despite RH in 40's. Once heavier precip moves in towards evening and better upper level support from main wave, rates should pick up. 

[Malacka11]

Crack rock fairy shit commencing. Quite honestly in my mind I was worried we'd be shut out entirely if we didn't lock it in for real so it's nice to see even if it never ends up accumulating 

[Baum]

Flakeage. 1” per 24 hour rates.

[Malacka11]

2 minutes ago, Baum said:

Flakeage. 1” per 24 hour rates.

If you couldn't see the flakes you literally can't tell yet but it's already blowing on the roads with every last breeze particle simulation style. Even with shit rates and zero expectations it's comforting to know we're at least not losing a single flake to melt

[ILSNOW]

current  virga radar

 

 

[Chicago916]

Flakes starting in Avondale

[cyclone77]

Lil pixies trickling down here atm.

[RogueWaves]

Wayne cnty/DTW cashes chips in these over-whelming cold patterns. Even when OHV gets the best far SEMI is invited to their party. 12/23/04 comes to mind and March '08 

[DocATL]

Sweet granular nothings in Naperville

[DocATL]

31 minutes ago, Malacka11 said:

Crack rock fairy shit commencing. Quite honestly in my mind I was worried we'd be shut out entirely if we didn't lock it in for real so it's nice to see even if it never ends up accumulating 

I mean there's got to be something in this about saturating the column, dendritic growth zones, and whatnot. Hoping for some strong ratios.

KLOT kind of eluded to quicker onset:

Radar shows virga has overspread northern IL and northwest IN
with very slow top down saturation noted as a closing "donut
hole" on our WSR-88D. This top down saturation process should
continue through the day with some light snow likely to
eventually develop from west to east across the area this
afternoon. It`s possible this process may be a tad quicker than
progged in current pops, so may eventually need to tweak the
timing up a bit. Initially, snow should be very small flake size
which should be very slow to accumulate.

[King James]

I’m happy with it. Looks like a snowy winter day out my window already

[ILSNOW]

 

[DocATL]

2 minutes ago, ILSNOW said:

 

It just picked up a bit...keep singing.

[ILSNOW]

Izzi

Forecast on track with no meaningful changes to previous
forecast for the approaching winter storm. I am concerned that
lake effect snow could overperform a bit very late tonight into
Sunday morning over northeast IL and into northern Lake Co
Indiana Sunday afternoon, but confidence is a bit too low to
justify an upgrade to a winter storm warning at this time.

Large winter storm is slowly approaching the area this afternoon
though very dry antecedent air mass is taking some time to
saturate from top down. WSR-88D imagery does suggests that the
low level dry air is being eroded and expect areas of light
snow and flurries to begin making it to the surface soon.
Light snow will likely continue tonight, especially south of
I-80.

Most of the ascent tonight appears to be the result of upper
level divergence in the right entrance region of developing
upper level jet streak over the western Great Lakes. As such,
strongest upward vertical velocities (UVVs) are progged to be
above 600 mb, well above the very deep DGZ where weak UVVs are
progged to be neutral or even weak subsidence. This suggests
that predominant snow type for most of tonight will be smaller
flake size and resultant lower snow:liquid ratio (SLR). Nudged
the forecast SLR down some, but possibly still too high if the
snow tonight is mostly pixie dust and low SLR. Confidence wasn`t
high enough to make any big adjustments to snowfall totals, but
that is something the evening shift will need to look at for the
first half of the event tonight.

By early Sunday morning, we start to get into an area of coupled
jets with some strengthening mid-level frontogenesis. This
could result in a period of stronger UVVs below 600mb and closer
to the DGZ. This may produce heavier snowfall rates Sunday
morning where larger dendrites result in higher SLRs, at least
in mesoscale band(s). The system snow should end from west to
east from mid afternoon Sunday through early evening.

One wildcard will be the lake enhanced snow late tonight into
Sunday. While there will be a strong frontal inversion between
800-850mb through the duration of the event, limiting the depth
of the lake induced convective instability. While the depth of
the instability looks to be rather shallow, the instability
below the inversion will be quite strong with lake-850mb delta T
values around 20C. This should result in very strong ascent below
the inversion, the majority of which will be smack dab in the
middle of the DGZ. I am concerned that seeder-feeder process
from strong synoptic ascent above 600mb could result in a band
of intense lake effect snow embedded within an area of lighter
snow and flurries. Wouldn`t be surprised to see snowfall rates
>=1" per hour with the lake enhanced snow Sunday morning into NE
IL, gradually shifting into NW IN Sunday afternoon. Certainly a
play for totals solidly over 6" into northeast IL if the lake
enhancement really gets going, but confidence isn`t high enough
to justify an upgrade to a warning at this time. Will be
something that later shifts will need to closely watch.

Intensity of the lake effect should begin to decrease Sunday
evening as it loses seeder-feeder with synoptic snows shifting
east of the area. Inversion heights are progged to come up a bit
Sunday evening, so did maintain likely pops for LES across
northeast IN Sunday evening. By late Sunday evening the LES
threat should push east of Porter County, so the midnight
expiration time for the winter weather advisory looks good for
Lake/Porter Counties.

[Malacka11]

At least the pavement gets covered quick even if no grass tips might be a big ask

[cyclone77]

19 minutes ago, ILSNOW said:

Izzi

Forecast on track with no meaningful changes to previous
forecast for the approaching winter storm. I am concerned that
lake effect snow could overperform a bit very late tonight into
Sunday morning over northeast IL and into northern Lake Co
Indiana Sunday afternoon, but confidence is a bit too low to
justify an upgrade to a winter storm warning at this time.

Large winter storm is slowly approaching the area this afternoon
though very dry antecedent air mass is taking some time to
saturate from top down. WSR-88D imagery does suggests that the
low level dry air is being eroded and expect areas of light
snow and flurries to begin making it to the surface soon.
Light snow will likely continue tonight, especially south of
I-80.

Most of the ascent tonight appears to be the result of upper
level divergence in the right entrance region of developing
upper level jet streak over the western Great Lakes. As such,
strongest upward vertical velocities (UVVs) are progged to be
above 600 mb, well above the very deep DGZ where weak UVVs are
progged to be neutral or even weak subsidence. This suggests
that predominant snow type for most of tonight will be smaller
flake size and resultant lower snow:liquid ratio (SLR). Nudged
the forecast SLR down some, but possibly still too high if the
snow tonight is mostly pixie dust and low SLR. Confidence wasn`t
high enough to make any big adjustments to snowfall totals, but
that is something the evening shift will need to look at for the
first half of the event tonight.

By early Sunday morning, we start to get into an area of coupled
jets with some strengthening mid-level frontogenesis. This
could result in a period of stronger UVVs below 600mb and closer
to the DGZ. This may produce heavier snowfall rates Sunday
morning where larger dendrites result in higher SLRs, at least
in mesoscale band(s). The system snow should end from west to
east from mid afternoon Sunday through early evening.

One wildcard will be the lake enhanced snow late tonight into
Sunday. While there will be a strong frontal inversion between
800-850mb through the duration of the event, limiting the depth
of the lake induced convective instability. While the depth of
the instability looks to be rather shallow, the instability
below the inversion will be quite strong with lake-850mb delta T
values around 20C. This should result in very strong ascent below
the inversion, the majority of which will be smack dab in the
middle of the DGZ. I am concerned that seeder-feeder process
from strong synoptic ascent above 600mb could result in a band
of intense lake effect snow embedded within an area of lighter
snow and flurries. Wouldn`t be surprised to see snowfall rates
>=1" per hour with the lake enhanced snow Sunday morning into NE
IL, gradually shifting into NW IN Sunday afternoon. Certainly a
play for totals solidly over 6" into northeast IL if the lake
enhancement really gets going, but confidence isn`t high enough
to justify an upgrade to a warning at this time. Will be
something that later shifts will need to closely watch.

Intensity of the lake effect should begin to decrease Sunday
evening as it loses seeder-feeder with synoptic snows shifting
east of the area. Inversion heights are progged to come up a bit
Sunday evening, so did maintain likely pops for LES across
northeast IN Sunday evening. By late Sunday evening the LES
threat should push east of Porter County, so the midnight
expiration time for the winter weather advisory looks good for
Lake/Porter Counties.

He's not the one who forecast 12-18" there earlier this season was he?

[Chicago Storm]

Just now, cyclone77 said:

He's not the one who forecast 12-18" there earlier this season was he?

he is not.

[Radtechwxman]

Pixie dust has commenced here. Time 2 b buried 

[RCNYILWX]

Oh just for full disclosure since I'm all about owning up to bad forecasts, my forecast earlier this week sucked (overnight snow the day before the evening squalls and snow bands that did work out). That was a different setup, but the dry air winning out there made me a little gunshy to feel confident the light snow would start much earlier.

I did have a hunch something like this might play out, but in the 00z and 06z TAFs last night, didn't have flurries until 4pm at DPA and 5pm at ORD, MDW, GYY. Still leaned earlier than explicit guidance though based on how the soundings looked, and had a prob30 (30% prob) group starting with the flurries onset before the 1-2SM stuff in the evening.

Someone should also tell many previous runs of the GFS that it is indeed snowing across much of northern IL today.

Sent from my SM-S936U using Tapatalk

[Jackstraw]

36 minutes ago, Malacka11 said:

At least the pavement gets covered quick even if no grass tips might be a big ask

I've learned to mow it like a golf green on the last mow of the year. Makes a duster a big dog lol

[sbnwx85]

I feel seen

DISCUSSION...
Issued at 224 PM EST Sat Jan 24 2026

Overall, no significant changes to the incoming winter storm.

A wintry weekend is underway or imminent for much of the US. Low
pressure over the TX/LA Gulf Coast slowly lifts north this evening
with a modest precipitation shield extending into the mid-
Mississippi valley where Arctic High Pressure has a grip over the
Midwest. This high pressure limits poleward moisture transport this
evening with its strong subsidence and bone-dry air mass (dew points
in the 10s-to-teens below-zero). Forecast soundings do show
saturation occuring prior to midnight ET for those along and south
of US 24 allowing for about 1-2" by daybreak Sunday; armchair
meteorologists may scoff Sunday morning about the lack of snow but
more is on the way.

Our primary period of prolonged, steady snowfall is during the day
Sunday and tapering off after sunset. This is when a second, more
potent low currently digging in over the Baja of California lifts
northeast through the Tennessee River Valley. By this time, high
pressure will have shifted northeast allowing for improved moisture
profile locally, but still cannot rule out being "robbed" of some
moisture transport with such a large precipitation shield across the
S Southeast US. The 12z suite of forecast guidance generally stayed
close to the existing forecast. There were some northward shifts in
CAMs (as well as the NAM). Balancing the dry air mass, subtle
northward shift of some guidance and reducing snow ratios a touch,
we`ve generally held course with this afternoon`s forecast package.

In coordination with neighboring offices, we did reduce the
inherited 20:1 snow ratios (now capped at (17:1); likely over-
boosted by the very cold air mass. Indeed, the 15k FT deep dendritic
growth zone is impressive, but overall forcing in the column is
modest as revealed by time-height cross sections. Nonetheless, a
fluffy snow and a brief period 1" per hour rates. These rates are
most likely around sunrise Sunday morning as an area of mid-level
frontogenesis passes overhead. Wind gusts of 15 to 25 mph will
result in areas of blowing and drifting snow, with easterly wind at
the start of the evening "backing" (counter-clockwise) to become
westerly by the snow`s end.

A single band of lake effect develops Sunday night as this surface
low becomes centered off the New England coast. The band tracks from
the western Lake Michigan shore to the east which will limit
residence time but 1" per hour rates are expected as the band swings
through. Depending on its residence time for the Monday morning
commute, additional winter weather headlines may be needed for
Michiana.

 

[Jackstraw]

I can here the clang of swords overhead as the demon dry air and the light of flakes clash!

[mimillman]

Tiny flakes in Logan square