12/8 - 12/9 "I-80 Corridor Snow Event"

[Bellona]

I don't envy NWS in Iowa right now. Seems every run waffles back and forth. Thermals are iffy, etc. I'm thinking maybe wwa hwy 20 north? 

[Hoosier]

For the Chicago area posters/lurkers, this is getting a little more interesting for much of the metro.  Don't expect big amounts but it could thump pretty good for a while.

[james1976]

Advisories are being hoisted!

[CentralNebWeather]

Already some businesses and clinics are going with late starts.  No schools listed yet, but I know our supt. will be out early in the morning.  My guess is we go with a 10 AM start then see the extent of the ice.  Some of the latest models show the ice starting around sunrise and lasting until early afternoon.  If that is the case, there will be a lot of closings in the area.

[Hoosier]

Here's a NAM forecast sounding from northeastern IL on Friday.  Nice lift with good omega present in the region of steep lapse rates aloft, and this also resides in the DGZ.  I think it's going to rip for a while, especially out around O'Hare and northward but perhaps even south of there.

 

[tStacsh]

recent GFS spits out some better accumulations 

[CentralNebWeather]

Our school district has a 10 am start tomorrow, though the message said watch for updates to a possible closing. We’ll see how bad the icing is. 

[jaster220]

4 hours ago, tStacsh said:

recent GFS spits out some better accumulations 

GFS should be a SR model. 

[jaster220]

5 hours ago, Hoosier said:

Here's a NAM forecast sounding from northeastern IL on Friday.  Nice lift with good omega present in the region of steep lapse rates aloft, and this also resides in the DGZ.  I think it's going to rip for a while, especially out around O'Hare and northward but perhaps even south of there.

 

Models aren't really showing much/any accums for Chi-town. Guessing this will be a "now-cast" because the thermals are right on the hairy edge between SN/RN and may come down to rates. (0z looks like it took a slight step backwards). 

[jaster220]

The 12z Euro snow map literally brings snow up the edge of the Metro here and hits a wall. Can clearly see the UHI kill the snow as I've outlined in red. 

I think only the Canadian shows any real amount now for here. 

[jaster220]

5 hours ago, tStacsh said:

recent GFS spits out some better accumulations 

yep. 18z put yby squarely back in the game. Like GRR says, mitigating factors will decrease the net effects of whatever does fall, but you may just make up for the weak performance of the Nov clippers last year with this one. 

[Hoosier]

23 minutes ago, jaster220 said:

Models aren't really showing much/any accums for Chi-town. Guessing this will be a "now-cast" because the thermals are right on the hairy edge between SN/RN and may come down to rates. (0z looks like it took a slight step backwards). 

Yeah, I'm not saying there's going to be sig accums, just that I think there will be a nice burst of mod-hvy snow especially north of the city.

Btw, check your PMs.  

[jaster220]

On 12/5/2022 at 9:01 AM, Niko said:

FWIW, the snowline came further south than what it was yesterday, so that's good news. Now has Detroit in the snow color.

 

On 12/5/2022 at 9:44 AM, Clinton said:

6z Euro Control juicer east this time.

Nope. 

Still, respectable midlevel height falls and diffluent flow aloft
will move across the region 18z Friday - 03z Saturday, and with
eventual column saturation, a period of scattered light rain,
rain/snow mix will be possible across much of the region with
greatest likelihood south of I-69. Questions still remain on
quickness of wet bulbing/evaporative cooling processes with regards
to snow potential, but overall light QPF amounts (under 0.10 inch
with snow ratios under 10:1) will lend any accumulating snow amounts
to a few tenths of an inch at best.

[CentralNebWeather]

No school here, just announced. Freezing drizzle has made it extremely slick. 

[bud2380]

Still a lot of model disagreement and the event is almost underway.  The NAM and GFS are much further north than the Canadian and HRRR in particular.  The Euro is more in between.  It's not a very wide band, so a little wobble either way will mean a hit or miss for some.  

[gabel23]

1 hour ago, CentralNebWeather said:

No school here, just announced. Freezing drizzle has made it extremely slick. 

No late start but I'm wondering if we get an early out. We haven't had any precip thus far but did have frost this morning. Temps are in the teens; waiting to see if the precip makes it up to us. 

[OmahaSnowFan]

It’s a race to get above freezing here. Precip hasn’t started and is supposed to arrive later then expected.

Dropped all the way to 17 this morning but back up to 25 and rising pretty quickly.

Either way, what once looked like a 1/2” of moisture is now down to .1”-.2” tops on most models.

[CentralNebWeather]

13 minutes ago, gabel23 said:

No late start but I'm wondering if we get an early out. We haven't had any precip thus far but did have frost this morning. Temps are in the teens; waiting to see if the precip makes it up to us. 

It is unbelievably slick. The drizzle is very heavy, almost a light rain at 21 degrees. I think every school around here that was a 10 am start is now closed. I bet you get out early. 

[gabel23]

1 hour ago, CentralNebWeather said:

It is unbelievably slick. The drizzle is very heavy, almost a light rain at 21 degrees. I think every school around here that was a 10 am start is now closed. I bet you get out early. 

Yes sir we are! Drizzle has just moved in within the past 30 minutes. 

[BMT]

Seems like some of the latest short term models bring some hope a bit further south.  would be nice to have some sort of frozen precip.  I'm riding the line

[james1976]

27 minutes ago, BMT said:

Seems like some of the latest short term models bring some hope a bit further south.  would be nice to have some sort of frozen precip.  I'm riding the line

Wow the HRRR looks nice

[Bellona]

Few of the short term models show a lot of ice around Waterloo. Wonder if that could really take place?

[gabel23]

Wow Thunder ice/snow showing up!

[Grizzcoat]

Apparently OMX issues WWA for just rain at KOMA?>?> What am I missing?

[james1976]

12 minutes ago, gabel23 said:

Wow Thunder ice/snow showing up!

 

IMG_2193.MOV 385.05 kB · 1 download

Thats a good sign. I think this system will have some dynamics. Nice to see it maturing.

[bud2380]

18z HRRR really drops some big snow totals.

 

[westMJim]

With the updated forecast it still looks like it will be too warm in most areas to see much in the way of snow accumulations  over the next week or so. The when it gets colder it becomes dry.  So will there be a White Christmas? Too soon to tell.

[jaster220]

16 minutes ago, westMJim said:

With the updated forecast it still looks like it will be too warm in most areas to see much in the way of snow accumulations  over the next week or so. The when it gets colder it becomes dry.  So will there be a White Christmas? Too soon to tell.

@Tom thinks we'll get something, tho the pattern has not shown that to date. Big wound-up N Plains storms followed by CAD or limp systems. Until Feb??

[james1976]

Upgraded to a warning in north central IA but it's a bit NW of me. They lowered totals for my area down to 1-4".

[OmahaSnowFan]

Ended up with a whopping .10” of rain.

[Clinton]

28 minutes ago, OmahaSnowFan said:

Ended up with a whopping .10” of rain.

Kind of a bust here with rainfall.  Models showed .25 to a half inch of rain and I got a trace.

[gabel23]

50 minutes ago, OmahaSnowFan said:

Ended up with a whopping .10” of rain.

Your weather station is way better than mine. I know we have had precip after the slip and fall I had tonight taking out the garbage, but nothing recorded.  I'm guessing we aren't to far off your total though 80 miles to the west. Ice sucks. 

[Bellona]

It was supposed to only get down to 33 tonight in Waterloo, it is currently 28. Should help with ratios a bit. 

[OttumwaSnomow]

Well, we sent a 2 truck  plow crew to do some plowing in nw Iowa, north west of Fort Dodge.   They tell me repeated  lightning  and thundersnow!   Here its 38F and a few showers.

 

[OmahaSnowFan]

Holy crap!! 3”/hr snowfall rates in Sioux Falls!!

 

[Grizzcoat]

3 minutes ago, OmahaSnowFan said:

Holy crap!! 3”/hr snowfall rates in Sioux Falls!!

 

Was just gonna post this- beat me to it. But snow increasing rapidly remark of 3" an hour is impressive.

Data at: 0304 UTC 09 Dec 2022

KFSD 090256Z 09009KT 1/2SM SN FG VV005 01/M01 A3010 RMK AO2 SLP213 SNINCR 3/5 P0019 60050 I3002 T00111011 58013 RVRNO

[OmahaSnowFan]

41 minutes ago, gabel23 said:

Your weather station is way better than mine. I know we have had precip after the slip and fall I had tonight taking out the garbage, but nothing recorded.  I'm guessing we aren't to far off your total though 80 miles to the west. Ice sucks. 

Luckily we’ve been all rain/sleet here. Right when the convective showers started to form I had one pass over our house and drop some heavy sleet and ice pellets for a couple minutes. Here’s the tail end of the heavy rates

 

[james1976]

Snow is knocking on my doorstep. Looks heavy on radar. Hoping for some thundersnow! DMX bumped me back up to 2-4"

[gabel23]

6 hours ago, gabel23 said:

Wow Thunder ice/snow showing up!

 

IMG_2193.MOV 385.05 kB · 1 download

Now this!!! Things are over performing with this system for sure! Although we only experienced freezing drizzle/fog/rain all day here; I'm hopeful this is a sign of surprising storms to come! 

 

https://twitter.com/weather_buffalo/status/1601055930447056897?s=20&t=Q3cOlC6Rprj9mQzKfLRXDQ

[Andie]

18 minutes ago, hawkstwelve said:

Wife is reporting thundersnow with very loud thunder cracking overhead and heavy snow. I am SO FREAKING JEALOUS it's hard to contain it. Always wanted to experience thundersnow. Ugh!

I’ve experienced it once in this crazy Texas idea of snow!   It’s downright freaky.   
The sky was dark, snowing like crazy then it would thunder periodically.  
So, incongruent.  

[james1976]

Literally just started rain/sleet mix here. I really hope I don't deal with mixing all night. Hope it changes to snow soon. I'm at 32°

[gabel23]

Big ole fatties falling down in Sioux Falls! Sorry you missed out @hawkstwelve

 

https://twitter.com/shawncable/status/1601036279596331008?s=20&t=Eymp02j6EZxfketC0fS4ng

[gabel23]

4 minutes ago, hawkstwelve said:

Security camera caught one of the cracks as my family was shoveling the driveway. All that snow has fallen since around 4PM central. It was so unexpected and loud they ran inside almost immediately. 

I. Cannot. Believe. I. Missed. This. 

That's amazing and so sad all in one reply!!!!

[james1976]

Sorry you are missing out on that @hawkstwelve!

[Bellona]

29 minutes ago, james1976 said:

Snow is knocking on my doorstep. Looks heavy on radar. Hoping for some thundersnow! DMX bumped me back up to 2-4"

Are you back in Iowa right now?

[james1976]

4 minutes ago, Bellona said:

Are you back in Iowa right now?

Yeah for the weekend. 32 and raining right now. Hope it changes over soon. 

[james1976]

Radar is really filling in across IA. Sucks that there isn't more cold air. Great dynamics with this system.

[Bellona]

4 minutes ago, james1976 said:

Radar is really filling in across IA. Sucks that there isn't more cold air. Great dynamics with this system.

Sitting at 32 and rain here as well. Was 28 earlier...

[Hawkeye]

The latest HRRR has really dropped totals in the warning area around Mason City.  Now it's bulls-eyeing far northeast Iowa near Decorah with 10".

[james1976]

Temp has risen to 34 now lol. What a waste. Was raining hard at 32....now it looks like a bit more sleet mixed in....even though the temp has risen. Thermals are a mess with this thing.