Dec 29-Jan 2 potential storm event

[Thundersnow12]

9 minutes ago, purduewx80 said:

NAM is often far better with lower level thermals than other guidance, but it is a northern outlier with the sleet/freezing rain.

That said, the 12Z HREF (ensemble of hi-res SPC models) shows the mixing getting up to a Janesville-to-Milwaukee line overnight. 

We'll have a better idea of how the mixing line is trending in a few hours.

NAM concerned. Joey not a fan 

[A-L-E-K]

+SN at IRK 

[Hoosier]

Has anyone out looked out west to see which models are handling the mixing line the best right now?

I'd be more confident in discounting the NAM over its dry air issues than over its thermal profiles, but that is past experience talking because of how many times we have seen waa overperform.  On any individual event, it's certainly possible for the NAM to be too warm aloft, and hopefully this is one of those times for you folks in the main snow band.

[Chicago Storm]

2 minutes ago, Hoosier said:

Has anyone out looked out west to see which models are handling the mixing line the best right now?

Just was looking at that actually.

HRRR is very close, and the NAM is a bit too bullish.

Shall see how things evolve though.

[Hoosier]

Without actually doing a dprog/dt of models for the late week storm, it seems like there has been a shift toward a weaker/southeast track as it moves into the region.  IF that ends up being the case, then in theory, it would blunt the warm air surge just a bit and result in the snow/ice precip types hanging on for a longer duration of time, especially if the surface high maintains the same strength.

[A-L-E-K]

[hawkeye_wx]

Final Euro for wave #1.

[McHenrySnow]

Best Euro run yet for my backyard.

[Natester]

12z euro shifted SE for wave 2, just like the UKMET.

[hawkeye_wx]

3 minutes ago, Natester said:

12z euro shifted SE for wave 2, just like the UKMET.

Definite trend from the Euro, weakening and shearing east earlier.  This system peaks in the southern plains.

[hlcater]

And that is fine with me given the thermos it was going to have.

Miss. Me. With. That.

[Chicago Storm]

Just now, hlcater said:

And that is fine with me given the thermos it was going to have.

Miss. Me. With. That.

[SchaumburgStormer]

HRRR continuing to tick south/cooler with every run for todays event. 

[Hoosier]

5 minutes ago, hawkeye_wx said:

Definite trend from the Euro, weakening and shearing east earlier.  This system peaks in the southern plains.

Weaker system may ultimately cut down on qpf, but in a way that could be a more favorable setup for icing as a lower percentage of it would run off.  

[Radtechwxman]

Light snow here now in KPIA. It saturated pretty quickly. 

[Hoosier]

Alek life 

[kevlon62]

Alek life 

Life on easy street.

Sent from my SM-N960U using Tapatalk

[A-L-E-K]

ice proof, tornado proof, i got it all

[tuanis]

DVN seems to be having a tough time with saturation, but looks like that should change within the hour - pretty much on schedule with HRRR depiction.

[featherwx]

Already almost an inch on the ground and still coming down pretty good here in Nauvoo, IL (right across the Mississippi from the southeast corner of Iowa) even though the NWS point and click now says only an inch total for the whole day. My girlfriend and I are here in a cabin on the river for a little vacation away from Chicago, so this is my first real snow of the season  

[tuanis]

5 minutes ago, featherwx said:

Already almost an inch on the ground and still coming down pretty good here in Nauvoo, IL (right across the Mississippi from the southeast corner of Iowa) even though the NWS point and click now says only an inch total for the whole day. My girlfriend and I are here in a cabin on the river for a little vacation away from Chicago, so this is my first real snow of the season  

Pretty sweet looking band moved over your head during the past hour per radar. Hope that translates well to the east.

Radar really filling in nicely down that way over the past few scans.

[Hoosier]

Excluding things like freezing drizzle, can't recall experiencing many back to back icing events within a few days.  Maybe once or twice.  Even though amounts won't be huge, still kind of interesting/different. 

[NEILwxbo]

8 minutes ago, featherwx said:

Already almost an inch on the ground and still coming down pretty good here in Nauvoo, IL (right across the Mississippi from the southeast corner of Iowa) even though the NWS point and click now says only an inch total for the whole day. My girlfriend and I are here in a cabin on the river for a little vacation away from Chicago, so this is my first real snow of the season  

Good to hear for us upstream

[NEILwxbo]

Latest LOT afd thinks this could overperform, talks about expanding WSW southeast 

[ChiTownSnow]

LOT

"National Weather Service Text Product Display" https://forecast.weather.gov/product.php?site=LOT&issuedby=LOT&product=AFD&format=CI&version=1&glossary=1

While again see no reason yet that the snow side won`t perform or

perhaps locally overperform, there`s signs on the guidance that

the mix/change to brief sleet then freezing rain could occur a bit

earlier this evening. This would be followed by steady rates, and

potential for localized ice accums north of I-80 up to 0.2 to

0.25". Should confidence increase in snowfall amounts needing to

be adjusted upward with southward extent, plus the anticipated ice

accretion tonight, may need to consider another expansion of the

Winter Storm Warning, including deeper into the Chicago metro. If

we decide to expand the warning, will look to get that update out

as early as possible this afternoon.

 

[A-L-E-K]

high quality banding between PIA and DVN now, just give me a couple hours of that this evening and it's a W

[CheeselandSkies]

HRRR really wants to keep the main band south of Madison, only 4.1" by  hour 17 while most local forecasts over the last couple days have had us in the 6-10" bullseye.

[ChiTownSnow]

Local temp crept up to 30 degrees 

 

[McHenrySnow]

1 minute ago, ChiTownSnow said:

Local temp crept up to 30 degrees 

 

29ª up here near the Wisconsin border.

[Hoosier]

13 minutes ago, ChiTownSnow said:

LOT

"National Weather Service Text Product Display" https://forecast.weather.gov/product.php?site=LOT&issuedby=LOT&product=AFD&format=CI&version=1&glossary=1

While again see no reason yet that the snow side won`t perform or

perhaps locally overperform, there`s signs on the guidance that

the mix/change to brief sleet then freezing rain could occur a bit

earlier this evening. This would be followed by steady rates, and

potential for localized ice accums north of I-80 up to 0.2 to

0.25". Should confidence increase in snowfall amounts needing to

be adjusted upward with southward extent, plus the anticipated ice

accretion tonight, may need to consider another expansion of the

Winter Storm Warning, including deeper into the Chicago metro. If

we decide to expand the warning, will look to get that update out

as early as possible this afternoon.

 

Wonder if the better icing may end up I-80 south.  That is what majority of the guidance is hinting at with some exceptions like the NAM and GFS.  In part will depend on how long precip takes to transition from sleet to freezing rain for the area north of I-80.