February 8th-11th Major Snowstorm

[james1976]

1.7"

[Tabitha]

I'll bet you a penny that by Monday night; when all is said and done; the Rapid City NWS office measures more snow than Chicago O'Hare  from now until then.

 

So you won't have to take my ruler's word for it.

 

Rapid City NWS WFO might be the only station around here that does worse than me.

 

I'm ahead of them by 2.8" on the season...17.2" to 14.4".

 

Just 7/10ths of an inch of snow from this system down at the Rapid City NWS WFO as of 5 PM MDT...so beating O'Hare is going to be a very tall order indeed!

 

It is snowing rather earnestly in the Black Hills at present and should continue to do so into Friday...so we'll see what happens.

 

I have snow, blowing snow, and very dense fog at 6:42 PM MDT...with a temp of 11 F and a very gusty NE wind.

 

To show the crazy temp gradient, it was raining at Custer at 6 PM MDT with a temperature of 37 F; Custer being about 25 miles to my SW.

 

Custer is also over 5000' in elevation...so the warm layer aloft very noticeable.

[bud2380]

Cedar Rapids sure looks like they are going to hang on to that snow band for awhile yet

[bud2380]

The radar is showing signs of sinking south but it’s not even snowing here right now even though the radar shows it should be. So that seems like a bad sign.

[Madtown]

looks like the southern edge has stopped it's march north

[Hawkeye]

Cedar Rapids sure looks like they are going to hang on to that snow band for awhile yet

 

I thought the back edge would lift into the CR area by evening, but radar continues to fill in along the edge and bring continued light to moderate snow into the metro.  I still expect to get a lull at some point later, but it's decent so far.

[Hawkeye]

1.5 inches here so far, snowing nicely.

[Iowawx]

DVN issued an update to their AFD saying that they think the heaviest band will be in Cedar Rapids and Dubuque.

[gosaints]

I hope the 3km Nam is drunk tonight. The width of good stuff really went downhill.

[GDR]

This thing seems way north of the models.

[Hawkeye]

DVN issued an update to their AFD saying that they think the heaviest band will be in Cedar Rapids and Dubuque.

 

Area Forecast Discussion...UPDATED

National Weather Service Quad Cities IA IL

756 PM CST Thu Feb 8 2018

 

.UPDATE...

Issued at 749 PM CST Thu Feb 8 2018

 

Very narrow band of heavy snow forming across central Iowa will

track east through the late evening and overnight. Hires guidance

appears to be slightly north of where the heavy band of snow will

be. Think the band will be between CID and DBQ. H85 fgen seems to

be a good prognosticator for where the band is currently. Cross

sections suggest that the forcing may be the H7 fgen later in the

period. Regardless, latest forecast attempts to capitalize on

where the band is. Have brought down amounts for the QC as snow is

gradually shifting north.

[GDR]

Is this thing craping out before our eyes?

[bud2380]

Nam now showing 3-4” tomorrow night into Saturday morning for Cr and IC. That might be our best shot down here

[shakjen]

Maybe I will have better luck with round 2 on Saturday.

[Madtown]

.....lools like trash except the 10mi wide band.

[St Paul Storm]

I hope the 3km Nam is drunk tonight. The width of good stuff really went downhill.

You getting snow down there? Radar looks good right now. Even a few flakes up this way.

[gosaints]

You getting snow down there? Radar looks good right now. Even a few flakes up this way.

Ya snowing pretty good now. Might squeak a couple inches

[james1976]

2.1" here. Constant moderate snow here. However.....not liking that dry air moving in soon. Radar is filling in behind it though.
​PS: That is a very narrow heavy band forming across C IA. Dang!

[hlcater]

God DVN I hope you're right. The look on guidance is absolutely terrible. Shafted by 5 miles. I'd rather give Duluth snow than deal with this.

[james1976]

I'm averaging about 1/2" per hour rates so far with this system.

[Money]

Ya snowing pretty good now. Might squeak a couple inches

Radar looks solid for 2-4 ish for us which is better than what it was showing a day or two ago

[Tony]

Flake size not that good for the past hour

[gosaints]

Radar looks solid for 2-4 ish for us which is better than what it was showing a day or two ago

When you look at how narrow the solid fronto band is gonna be it really makes on realize how much of a thread the needle this turned into

[Sciascia]

 

Area Forecast Discussion

National Weather Service Chicago/Romeoville, IL

813 PM CST Thu Feb 8 2018

 

.UPDATE...

813 PM CST

 

No big changes planned to the overall forecast for the storm,

however, will likely move up the end time of the warning Friday as

the brunt of the snow will likely have fallen by mid-late morning

Friday in the warning.

 

Regional radar composite shows a long band of mostly light to

moderate snow extending from northern IL WNW into SD. A short wave

trough over the Dakotas early this evening shows up fairly well

on GOES-16 differential water vapor RGB. This shortwave is

forecast to shear quickly into the western Great Lakes Friday

morning, shearing out/weakening as it translates eastward.

 

Primarily light-moderate snow will continue this evening as

thermally direct circulation in the right entrance region of

120kt+ 250mb jet supports continued low-mid level frontogenesis

over about the northern 2/3rds of the CWA. As the Dakota`s

shortwave translates eastward, guidance suggests a strengthening

of the lower level f-gen and a resultant uptick in the UVVs over

northern IL.

 

Forecast vertical cross sections through the frontal band are a

bit worrisome for our double digit snowfall forecast amounts. The

last several runs of the RAP and 18z run of the NAM show virtually

no negative saturated EPV, which indicates that the atmosphere is

progged to be relatively stable and not primed for narrow intense

banded snow. In addition, guidance suggests that areas of stronger

f-gen will be somewhat transient in nature. While these factors

are concerning, short range high-res guidance continues to

advertise very beefy QPF values overnight into at least the first

part of Friday morning, so not planning any changes to our

forecast snowfall totals at this point.

 

There has been a pretty consistent signal across the spectrum of

model guidance suggesting that the meaningful snowfall will shift

mainly south of the winter storm warning area between 12-18z

Friday as shearing out shortwave passes east and associated height

falls nudge the upper jet and associated entrance region a bit

farther south. Given the expectation that snowfall across much of

the warning area will waning prior to 18z, think that for

messaging purposes an earlier end time to the warning is

justifiable. Latest guidance suggests that additional snowfall

accumulations beyond late morning would be somewhat trivial where

the warning is in effect.

 

Working on some fine tuning to grids and will have an updated WSW

and grids/derived products out shortly.

 

- Izzi

[Tony]

The above from LOT is not good at all.

[BrianJK]

Izzi already having doubts:

 

 

Forecast vertical cross sections through the frontal band are a

bit worrisome for our double digit snowfall forecast amounts. The

last several runs of the RAP and 18z run of the NAM show virtually

no negative saturated EPV, which indicates that the atmosphere is

progged to be relatively stable and not primed for narrow intense

banded snow. In addition, guidance suggests that areas of stronger

f-gen will be somewhat transient in nature. While these factors

are concerning, short range high-res guidance continues to

advertise very beefy QPF values overnight into at least the first

part of Friday morning, so not planning any changes to our

forecast snowfall totals at this point

[james1976]

Highest rates right now. Bigtime thread the needle. I'm sitting right on the north edge of the heavy band. It keeps feeding in from the west.
​Some of those dry radar returns to my NW have filled in so that's great to see as well.

[FV-Mike]

Izzi already having doubts:

 

 

Forecast vertical cross sections through the frontal band are a

bit worrisome for our double digit snowfall forecast amounts. The

last several runs of the RAP and 18z run of the NAM show virtually

no negative saturated EPV, which indicates that the atmosphere is

progged to be relatively stable and not primed for narrow intense

banded snow. In addition, guidance suggests that areas of stronger

f-gen will be somewhat transient in nature. While these factors

are concerning, short range high-res guidance continues to

advertise very beefy QPF values overnight into at least the first

part of Friday morning, so not planning any changes to our

forecast snowfall totals at this point

 

thought it was odd that he contradicts himself when he talks about the high-res guidance QPF

[FV-Mike]

Highest rates right now. Bigtime thread the needle. I'm sitting right on the north edge of the heavy band. It keeps feeding in from the west.

​Some of those dry radar returns to my NW have filled in so that's great to see as well.

that band in fort dodge, has to be dumping

[Craig-OmahaWX]

Wow 4km nam and regular nam look good for 3 to 5 here!

[hlcater]

I'm in the perfect spot, for the time being. It doesn't look like I will be all night. But I've been under that heavy band for awhile and I've got to be approaching 3" by now. If this could keep up all night...

[Tony]

We are only a couple hours into this so will have to let it play out but signs so far are discouraging.

[james1976]

I'm in the perfect spot, for the time being. It doesn't look like I will be all night. But I've been under that heavy band for awhile and I've got to be approaching 3" by now. If this could keep up all night...

You have more than me so far!

[Minny_Weather]

I'll be satisfied with nothing less than 4" here. Under that will just be another nuisance. I love snow but I'm getting tired of these nickel and dimers really fast.

[bud2380]

DVN may as well suck it up and cancel the winter storm warning for the i80 corridor.

[james1976]

Just measured 2.6". Dumping good but flakes are a bit smaller now.

[james1976]

DVN may as well suck it up and cancel the winter storm warning for the i80 corridor.

 

Feel bad for you. You could literally throw a rock and hit the heavy band. That's a nasty cutoff all along that southern edge.

[Niko]

Accumulations could end up being higher further north than predicted. Expect changes. Better sampling by tomorrow.

[james1976]

Waterloo is gonna get destroyed if that band keeps moving east and holds together.

[Hawkeye]

The back edge is just about to lift through Cedar Rapids, and it may remain north for a while.