February 21-23 Major Winter Storm

[OrdIowPitMsp]

3 minutes ago, cyclone77 said:

Take it to the bank and cash it, this is money right here.

 

27.3” imby. I’ll be seriously concerned for my roof if that verifies. Still have tons of snow up there. 

[beavis1729]

This event looks to mimic the infamous January 1999 storm, but 150 miles further north. 

[WestMichigan]

7 hours ago, ILSNOW said:

12z Euro (way to early) agrees with you ice comment

Hard pass on that junk.  Hoping nobody has to deal with that much ice.

[Baum]

Call me crazy, but I think Chicago can reel this one in......or I'll head to Milwaukee.

[Hoosier]

20 minutes ago, Baum said:

Call me crazy, but I think Chicago can reel this one in......or I'll head to Milwaukee.

Seems like a tall order from a snow perspective.  Something like this is more of a possibility (not saying it's likely though)

 

[cyclone77]

If we're not gonna get warm enough for storms I'll take a raging sleet storm.  At least it'd be interesting.

[WestMichigan]

53 minutes ago, cyclone77 said:

If we're not gonna get warm enough for storms I'll take a raging sleet storm.  At least it'd be interesting.

Just had one of those.  Almost 2" of maybe 3:1 concrete is still sitting on my driveway.  I think I am going to wait for it to melt out before the next round of ice hits.

[RCNYILWX]

Seems like a tall order from a snow perspective.  Something like this is more of a possibility (not saying it's likely though)
 

December 28, 2015 if the low manages to take a more southerly path toward the area.

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[sbnwx85]

00z GFS pretty much the same as 12z. 00z Canadian came far enough south to bring significant icing to Northern Indiana/Illinois. Going to be fun to track this one.

[HillsdaleMIWeather]

[HillsdaleMIWeather]

Goddamn

[RCNYILWX]

Goddamn

The FRAM (freezing rain accumulation model) estimate output.

Ice Accumulation Reference - Forecasting https://training.weather.gov/wdtd/courses/woc/winter/fcst-hzds/ice-storm-accum/presentation_content/external_files/Ice%20Reference%20v1.pdf

[Hoosier]

Was perusing some forecast soundings in the freezing rain zone and holy cow at the warm layer aloft.  Very thick and it gets pretty warm in parts of the target area.

[frostfern]

Another slop-fest.  The potential for mixed p-type convection is concerning.

[Hoosier]

0 in Fargo and 70s in St. Louis

 

[A-L-E-K]

Ice isn't happening u guys

[Frog Town]

1 hour ago, A-L-E-K said:

Ice isn't happening u guys

Antecedent conditions do not favor ice like that..at least in the Chicago to Detroit corridor.  

[roardog]

20 minutes ago, Frog Town said:

Antecedent conditions do not favor ice like that..at least in the Chicago to Detroit corridor.  

That matters to a point but if surface temps get low enough, there will be problems on trees and power lines even if the roads aren't that bad. I was skeptical back in April 2003 of significant icing but with temps in the upper 20s, we even had ice accretion during the day with an early September sun angle.

[Powerball]

12 hours ago, cyclone77 said:

If we're not gonna get warm enough for storms I'll take a raging sleet storm.  At least it'd be interesting.

You say that now.

But once you've had to suffer through 12 straight hours of non-stop pinging like some of us, you'll be singing a different tune...

[Powerball]

8 hours ago, Frog Town said:

Antecedent conditions do not favor ice like that..at least in the Chicago to Detroit corridor.  

Precip rates and how cold the rain droplets are can be important factors as well.

If the precip rates are heavy, with marginal temps, much of it will just run off and not accumulate. 

Just as well, if the rain droplets aren't supercooled, they will struggle to accumulate with below frerzing temps as well.

[Indystorm]

Leery of ice IMBY or anywhere nearby of the magnitude shown.  Would rather have a nice t  storm like I had here on Jan. 3, 2023.  Enjoyed the recent 3 inch snow but I am ready for an early spring since I saw my first robin of the season yesterday.

[Hoosier]

Of course there will be ice in this setup.  It's about as certain as death and taxes.  The main questions are magnitude and corridor (though the model agreement on corridor is almost freaky that you wonder if it can hold all the way until go time).

Let's take a trip down memory lane.  Toward the middle of March 1991, there was a really bad ice storm that affected a good chunk of northern Indiana and down toward the Lafayette-Kokomo area.  Temps in the days leading up were in the 40s and 50s.  I don't how the roads were, but I know what the trees looked like because I've seen the pics.  There was a lot of tree damage and power outages, and it's safe to say it was one of the worst ice storms to ever impact that part of Indiana. 

Tree and elevated object temperatures follow along more closely with the air temp than something like a paved surface.  Antecedent conditions aren't really going to matter when it comes to getting ice on these types of objects.  We have seen the opposite of this coming out of a deep cold spell where air temps can be in the mid-upper 30s and the ground will still be icing for a while but the trees aren't.

[sbnwx85]

I’d imagine it would be tough to get much ice along the Illinois/Wisconsin side of the lakeshore with water temps in the mid-30’s and an east wind. Otherwise, it looks like a nasty storm where ever that corridor sets up.

[RCNYILWX]

I’d imagine it would be tough to get much ice along the Illinois/Wisconsin side of the lakeshore with water temps in the mid-30’s and an east wind. Otherwise, it looks like a nasty storm where ever that corridor sets up.

Yep was going to make that point regarding Alek's post, would have to be a much colder air mass to overcome a milder boundary layer from flow off the lake and get any noteworthy ice in Chicago.

Still think there's a scenario in which sleet is higher end in this setup farther south into the metro. Probably tougher for that as currently modeled with the magnitude of the warm nose though, would need stronger low level CAD to refreeze into sleet, while southern WI looks more favored at the moment.

[Brian D]

Prez day clipper (3-6"), then winter storm. MSP BOOM!! Lake effect going to help things my way with no ice. BRING IT!!

[Hoosier]

44 minutes ago, sbnwx85 said:

I’d imagine it would be tough to get much ice along the Illinois/Wisconsin side of the lakeshore with water temps in the mid-30’s and an east wind. Otherwise, it looks like a nasty storm where ever that corridor sets up.

I think it will depend on the finer scale details of the near-sfc cold layer.  If 925 mb temps are like -3C to -4C, then that should be able to offset a marine influence enough to keep temps below freezing.  Of course if the low level cold layer is cold/deep enough, then it would tilt things more toward sleet, with the better chance of sleet currently being with northward extent into WI.

[RogueWaves]

So, we're shooting for sleet. 12-28-15 was great but don't see the stout cold we had going for us with that. No GEOS either

 

[Hoosier]

Here are two GFS forecast soundings valid at the same time.  One is from Waukegan and one is from Rockford.

First up, Waukegan...

 

Here we see a deep warm layer above 0C from just under 850 mb all the way up to 700 mb.  There is a respectable cold layer colder than 0C underneath this, but its depth and magnitude is not quite like what the warm layer is.  There is also a bit of mid-level dry air/lack of saturation.  These factors point toward this being more of a freezing rain sounding instead of sleet.  If you notice toward the bottom of the graph, the solid red line is essentially touching the light blue dashed line, which represents sfc temps right around freezing.

 

Now going over to Rockford...

 

Here we see a deeper warm layer aloft that goes from about 900 mb to 700 mb, and it's also warmer.  There's also less of a cold layer underneath than there is at Waukegan at that same time.  Interestingly, despite this larger/warmer warm layer and less pronounced cold layer, you see similar sfc temps as Waukegan, which I have to believe is the model trying to account for marine influence vs no marine influence.  Even with sfc temps around freezing at Rockford on that forecast sounding, I would argue that it would be difficult to keep sustaining freezing rain given the absolutely massive warm layer aloft and marginal sfc temps, assuming this depiction is correct of course.

All in all, will be interesting to see how this turns out.  You'd put the icing threat north of Chicago at this point... especially the core of Chicago.  But I don't think it's as simple as to say that there won't be icing near the western shores of Lake Michigan.  It will likely depend on how far north you are.

[frostfern]

9 hours ago, A-L-E-K said:

Ice isn't happening u guys

I'm nervous for this area.  The early April 2003 setup was similar to this.  The models were all over the place a few days before, some having 70 degree warmth surging north into Michigan, but in the end the cold didn't budge.  There wasn't antecedent arctic air, but NE inflow was cold/dry enough to wet-bulb to around 30 under the heavy precip. The ground was mostly just wet, but the trees in my area got absolutely brutalized with 0.75-1.0"" ice coating.

[RCNYILWX]

Here are two GFS forecast soundings valid at the same time.  One is from Waukegan and one is from Rockford.
First up, Waukegan...

 
Here we see a deep warm layer above 0C from just under 850 mb all the way up to 700 mb.  There is a respectable cold layer colder than 0C underneath this, but its depth and magnitude is not quite like what the warm layer is.  There is also a bit of mid-level dry air/lack of saturation.  These factors point toward this being more of a freezing rain sounding instead of sleet.  If you notice toward the bottom of the graph, the solid red line is essentially touching the light blue dashed line, which represents sfc temps right around freezing.
 
Now going over to Rockford...

 
Here we see a deeper warm layer aloft that goes from about 900 mb to 700 mb, and it's also warmer.  There's also less of a cold layer underneath than there is at Waukegan at that same time.  Interestingly, despite this larger/warmer warm layer and less pronounced cold layer, you see similar sfc temps as Waukegan, which I have to believe is the model trying to account for marine influence vs no marine influence.  Even with sfc temps around freezing at Rockford on that forecast sounding, I would argue that it would be difficult to keep sustaining freezing rain given the absolutely massive warm layer aloft and marginal sfc temps, assuming this depiction is correct of course.
All in all, will be interesting to see how this turns out.  You'd put the icing threat north of Chicago at this point... especially the core of Chicago.  But I don't think it's as simple as to say that there won't be icing near the western shores of Lake Michigan.  It will likely depend on how far north you are.

I'd recommend grabbing the winter sounding from COD (just have to select winter and generate new sounding) or go to Pivotal Weather which automatically will give a winter sounding.

On the bottom right of the winter soundings, you'll see layer energy information, which is the Bourgoin method to determine precipitation types. It's analogous to CAPE and DCAPE, positive energy aloft and negative energy low level. The precip. type tab in BUFKIT uses the Bourgoin method.

Any positive energy of 25+ J/kg represents full melting, while sleet probabilities increase at -75 J/kg and below. Even with high positive energies (near or above 100 J/kg), negative energies of -100 J/kg or lower tend to allow for sleet to at least mix in and the higher magnitude negative energies can overcome high positive energies to result in primarily sleet. The preferred profile to use is the wet bulb vs. solely temperature based profile.

Two examples of this from the 12z ECMWF below, first from interior far northeast IL and the other from near the state line on WI side of the border.

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