February 8th-11th Major Snowstorm

[Tom]

00z GGEM...

 

[Craig-OmahaWX]

WOW. Now this makes me happy lol. Come on EURO...please mimic this lol. GGEM. 

 

http://maps3.pivotalweather.com/maps/models/gdps/2018020800/066/snku_acc.us_c.png

[Tom]

I’m going to bed before the UK and euro destroy my hopes.

Same here...nite buddy!

[hlcater]

Never really paid much attention to it earlier today.  This system is juiced.  I'm ecstatic to see nearly every model paint a ton of precip instead of trending the other way.  In fact, one can argue they are trending wetter overall.

I'm 100% satisfied with the 00z runs tonight. What was really irritating(to me at least) was that earlier literally everywhere that wasnt CR/IC was getting solid warning snows and we had the lowest totals in the eastern half of Iowa. As long as that doesn't transpire, we are golden. This is definitely a Chicago special, at this point, no matter what this system does, you seem like a lock for very solid warning snows.

[Tabitha]

Some snow flurries in the air here at 9 PM MDT; for the first time since Alf Landon stopped being presidential timbre.

 

Clearly, the man who stops it from snowing here is on coffee break.

 

Temp in the mid-20's and a light wind.

 

The snow has changed to freezing drizzle here; as expecting more than 5 minutes of normalcy (note the nod to W. Harding) was far too grand a request.

 

The temp being around 0 C @ 850 mb would be the likely culprit.

 

I'm still trying to figure out what I did to be on the receiving end of so much endless unpleasantness.

[NH4NU]

Crazy that the GDPS is also picking up on "the fork" that GFS was showing -- Glimmer of hope for us in EC Neb  

 

http://www.pivotalweather.com/model.php?m=gdps&p=snku_acc&rh=2018020800&fh=144&r=us_c&dpdt=

[Hawkeye]

00z UK is an improvement over the 12z... has 0.4" qpf over much of Iowa, with 0.6" poking into east-central Iowa east of CR.

 

http://img.meteocentre.com/models/ukmet_amer_00/accum/PA_000-072_0000.gif

[Hawkeye]

Here's a more precise 00z UK

 

[Craig-OmahaWX]

Here's a more precise 00z UK

 

UK_00zFeb08.png

D**n, such a sharp cut off to nothing here on that model lol. 

[Hawkeye]

Many of the 00z runs showed a favorable trend for my area.  However, the 00z Euro shifted even farther north in Iowa than it already was.  The forked tongue is present.  This euro is easily the worst of any for us tonight.

 

[dubuque473]

Looks fantastic.

[Sciascia]

GFS holding steady on track, but more snow overall.

[VMB443]

Winter Storm Warning here. Kind of surprised but I’ll take it!

[Tabitha]

The snow has changed to freezing drizzle here; as expecting more than 5 minutes of normalcy (note the nod to W. Harding) was far too grand a request.

 

The 6z models did not look too bad around here; and 2/10ths of an inch of new snow actually accumulated here as of 4:30 AM MDT.

 

The NWS Rapid City reported 1/10th of an inch new snow; I believe.

 

The snow is currently off to my NE; doing its usual diligent job of avoiding this area; but it seems that some of it will move back over this area later (I hope).

[westMJim]

I am still not feeling all that well. That nasty cold/flu turned into a case of Bronchitis, I hate it when that happens. It looks like the heaviest of the snow should stay just south of me this weekend, Had a good inch of new snow yesterday and what looks like a trace this morning. Have not felt good enough to take a measurement

[bud2380]

2nd winter storm warning of the year. DVN basically saying I hear you Euro but I don’t believe you. 6z runs still look pretty good for i80 on North. DVN mentioned a possible south shift in headlines.

[bud2380]

The HRRR currently advertising about a two county wide area of heavier snow in Eastern Iowa. Favoring counties along and in between highway 20-30. I80 on the southern edge. Still showing snow just not as heavy.

[Tom]

The much anticipated Winter Storm Warning upgrade has been made!  Gosh, waking up this morning felt like I was a kid again and the fact that I got butterfly's in my stomach confirmed the fact that nothing has changed since then.  Not sure about you guys, but tracking snowstorms is such a crazy hobby!

 

Meantime, it's quite odd how much drier the Euro has been trending over the past few runs.  LOT also mentions the fact that it was taken into account when they put up their forecast.  On the other hand, you can't argue the vast amount of modeling indicating on average of 1.0" qpf across N IL and places nearby.

 

Nice write up from LOT:

 

 

 

Main forecast concern begins later in the afternoon and this
evening. Strong upper wave is progged to dig south across the
Canadian Prairies into the Northern Plains today while downstream,
increasing southwest flow will help to tighten the baroclinic zone
across the midwest. Isentropic ascent will ramp up from the west
through the mid to late afternoon hours with top-down saturation
occurring by late afternoon or early this evening across the
western counties and spreading across the CWA by mid evening.
Isentropic ascent is expected to persist overnight and through
midday tomorrow then should begin to shift east out of the CWA.
Frontogenesis is progged to persist later into the day. NAM
guidance shows the strongest corridor of f-gen generally aligned
between the I-88 and I- 90 corridors while the GFS is slightly
farther south aligned more along the I-80 corridor. Soundings do
show relatively steep lapse rates above 700mb and both the NAM and
GFS indicate negative EPV atop the better f-gen which will allow
for a deep vertical response to forcing and makes a very strong
case for mesoscale banding to occur. Many hours of the event will
likely see quarter to half inch per hour snowfall rates, but also
expect several hours where rates approach or exceed an inch per
hour within any areas of heavier banded snowfall.

Models continue to paint an axis of around one inch QPF (06Z NAM
actually came in with 1.5 inches). Can`t ignore the ECMWF runs
which have been consistently lower on QPF (24-hr QPF around 0.40
compared to around an inch from the GFS/GEM/NAM). It has been an
outlier both in QPF amount and now with northerly extent of its
QPF axis, so generally have leaned away a from it. It does,
though, add a degree of uncertainty to the forecast and official
forecast QPF is more on the order of 3/4 of an inch. Thinking the
really high QPF totals will be primarily where the longer
duration mesoscale banding sets up.

 

 

A few pointers:

 

1)  NAM has been steadfast on the placement of the heaviest band of snow across N IL into S MI

2)  GFS is more robust on the width of the heaviest band which should give better confidence that the cut off to the south may not be as bad

3)  The meso-scale banding with this system is going to be insane (1-2"+/hr)

4)  Lehs is being depicted to start impacting NE IL Friday morning and lasting throughout the entire day into Friday evening

5)  The secondary piece (Sat-Sun) is trending back towards something a bit better than what was being shown over the past couple days

 

Woah, this is becoming quite the storm!

 

Latest 06z NAM/GFS...through Sat 6:00am...

 

 

 

http://maps1.pivotalweather.com/maps/models/nam/2018020806/054/snku_acc.us_mw.png

 

 

 

 

http://maps1.pivotalweather.com/maps/models/gfs/2018020806/054/snku_acc.us_mw.png

[Tom]

Last night's 00z Euro and now both the 06z GFS/NAM are showing an appreciable band of 3-6" of snow Sat-Sun somewhere from KC up towards the Lower Lakes.

 

I think I'm going to keep a separate thread for this one and prob wait another day to see if trends hold.  We could keep discussion on this though in this thread.

[Tom]

High rez 06z NAM has eye-popping juice factor...

 

[Minny_Weather]

All of the 6Z runs have us in a forkhole. Unreal.

[Minny_Weather]

We in Lincoln and Omaha need to cheer for a northward shift in the second wave, the first one MIGHT drop an inch here and I don't think that one will budge.

[shakjen]

Need it to come south just a few miles. I am right on the edge. Right along I-80

[snowstorm83]

We in Lincoln and Omaha need to cheer for a northward shift in the second wave, the first one MIGHT drop an inch here and I don't think that one will budge.

 

First wave is a lost cause. Think we still have a shot for the second wave if it can tick north a bit, OAX has 1-3" in the grids.

[Madtown]

Nam keeping the dream alive. Personally thinking is it still moves 30mi or so north. Wwa always seems to push a little more north. Looks like a block buster in Chi town. Weather channel there yet?

[gosaints]

Nam keeping the dream alive. Personally thinking is it still moves 30mi or so north. Wwa always seems to push a little more north. Looks like a block buster in Chi town. Weather channel there yet?

You may be right, but there isnt much WAA in this thing.. Hard to argue Chicago not being the place to be for this one.

 

The worry of course being that these meso bands can be extremely narrow.

[snowman1]

A few pointers:

 

1)  NAM has been steadfast on the placement of the heaviest band of snow across N IL into S MI

2)  GFS is more robust on the width of the heaviest band which should give better confidence that the cut off to the south may not be as bad

3)  The meso-scale banding with this system is going to be insane (1-2"+/hr)

4)  Lehs is being depicted to start impacting NE IL Friday morning and lasting throughout the entire day into Friday evening

5)  The secondary piece (Sat-Sun) is trending back towards something a bit better than what was being shown over the past couple days

 

I hope you're right on point #2 here Tom. Euro/NAM have still got me nervous. Good to read DVN discussing a southward shift of the heavy axis still possible.......

 

 

 

 

So, to be brief, all in all

went with a warning from 00z this evening to 00z Sat(Friday evening)

for heavier snow areas of 4-8+ along and north of I80, and sharp

snowfall gradient/tail off to the south. Had to do a buffer zone of

counties in a Winter Wx Advisory for 2-5 inches generally from

Marengo-Sigourney-Washington IA areas over to Aledo IL. Additional

shifts will have to watch for a general southward migration of prime

lift and heavier snowfall axis from the current fcst placement, thus

a headline shift south as well if needed over the next 12-18

hours.

[hlcater]

You may be right, but there isnt much WAA in this thing.. Hard to argue Chicago not being the place to be for this one.

 

The worry of course being that these meso bands can be extremely narrow.

Because of that they can sometimes overperform by a sizable margin as most models struggle to resolve them, the CAMs are really the only ones that fully can. Gonna be a nail biter with that band out here, but we seem like a lock for at least 6” even without the band. If CR area gets in it, the 10+ on the models may be achieveable. But in order to get that, we’d NEED that heavy band.

[Stacsh]

In my experience these meso-scale bands always shift a little north of whats projected.  I may be making that up in hoping they actually do shift about 30-50 miles north......

[Tony]

The much anticipated Winter Storm Warning upgrade has been made!  Gosh, waking up this morning felt like I was a kid again and the fact that I got butterfly's in my stomach confirmed the fact that nothing has changed since then.  Not sure about you guys, but tracking snowstorms is such a crazy hobby!

 

Meantime, it's quite odd how much drier the Euro has been trending over the past few runs.  LOT also mentions the fact that it was taken into account when they put up their forecast.  On the other hand, you can't argue the vast amount of modeling indicating on average of 1.0" qpf across N IL and places nearby.

 

Nice write up from LOT:

 

 

 

A few pointers:

 

1)  NAM has been steadfast on the placement of the heaviest band of snow across N IL into S MI

2)  GFS is more robust on the width of the heaviest band which should give better confidence that the cut off to the south may not be as bad

3)  The meso-scale banding with this system is going to be insane (1-2"+/hr)

4)  Lehs is being depicted to start impacting NE IL Friday morning and lasting throughout the entire day into Friday evening

5)  The secondary piece (Sat-Sun) is trending back towards something a bit better than what was being shown over the past couple days

 

Woah, this is becoming quite the storm!

 

Latest 06z NAM/GFS...through Sat 6:00am...

 

 

 

http://maps1.pivotalweather.com/maps/models/nam/2018020806/054/snku_acc.us_mw.png

 

 

 

 

http://maps1.pivotalweather.com/maps/models/gfs/2018020806/054/snku_acc.us_mw.png

Key word is Meso Banding. I can see NAM totals above if indeed this does happen so fun times ahead. Also, LES will also enhance snow rates as Tom mentioned and having it on our side the entire day is an added bonus.

[Tony]

Also nice to wake up to flakes flying in the air knowing that a bigger storm looms later in the day. Should not have any problems saturating later this afternoon.

[Tom]

12z NAM through 6:00pm on Friday...

 

http://maps1.pivotalweather.com/maps/models/nam/2018020812/036/snku_acc.us_mw.png

[gosaints]

 

This should give an idea of how narrow the weenie band could be

[Tom]

Woah, ORD SREF's are up to 11.21" through Sat 6:00am...

[Madtown]

[Tom]

 

This should give an idea of how narrow the weenie band could be

That almost looks like a "training" thunderstorm....I like the look...where ever that lines up it will be puking snow...hopefully the dendrites are large.

[gosaints]

another spread the wealth system

Ha ya.  there are gonna be some classic differences in amounts over tiny geographic areas

[Tony]

Took a glance at the omega profiles for tomorrow. I am not very well versed in this but what I have heard is tomorrow morning we could be looking at anywhere between 1.5" to 3" per hour rates for a couple hours at least. Anyone with a little more knowledge that would like to chime in on this?

[St Paul Storm]

12z NAM through 6:00pm on Friday...

 

http://maps1.pivotalweather.com/maps/models/nam/2018020812/036/snku_acc.us_mw.png

That gradient in Will County is ugly.

[Niko]

This will be a paralyzing snowstorm for some. TWC thinks DTW and northern burbs will be at a foot or more.

 

Edit: They feel confident of another snowstorm late Sat-Sun w more than 4"+. Cannot get any better than this . Back to back snowstorms are definitely my favorite combo.