New Year's Day Storm

[The Snowman]

3 minutes ago, bud2380 said:

3k NAM would be great by me.

 

Been some time since Omaha had a model run to swoon over!

Given recent trends, 3-4" (isolated 5") seems pretty fair in the city. Gradient is sharp enough that a minor northward shift could bring about several more inches, but that will be a nowcast-type item to examine. Cheers to the folks looking at double digits out of this thing, finally feeling like winter!

[mlgamer]

NWS Topeka has broken the WSW into two groups. Group one 4-8". Group two along and southeast of the Kansas Turnpike 2-5" with more sleet. I'm sure group one will be put in a warning and group two an advisory. Naturally, I'm in group two.   

[Sciascia]

LOT has issued watches for Chicago & other N IL counties.

Event:

Winter Storm Watch

Alert:

...WINTER STORM WATCH IN EFFECT FROM SATURDAY MORNING THROUGH LATE SATURDAY NIGHT... * WHAT...Steady, blowing snow and dangerous travel possible. Total snow accumulations greater than 6 inches and northeasterly wind gusts in excess of 40 mph are possible. * WHERE...Lake IL, DuPage, Northern Cook, Central Cook and Southern Cook Counties. * WHEN...From Saturday morning through late Saturday night. * IMPACTS...Travel could be very difficult. Widespread blowing snow could significantly reduce visibility, especially along the Lake Michigan shoreline. * ADDITIONAL DETAILS...The steadiest snow rates appear most likely between noon Saturday and midnight Sunday.

[ToastedRavs]

1 hour ago, The Snowman said:

NWS Omaha extends the Winter Storm Watch to cover Douglas & Sarpy counties; watch text indicates 2-5" so probably an impact-based watch instead of an amounts-based watch.

NWS in Des Moines also expanded watch north and west by one county each. Upped the text to include 8 inch amounts. Definitely coordinated between the offices

[Jack_GradStudent]

Just doing some comparisons between operational runs of the nam, gfs, and euro. 

Speed: Gfs is the slowest, followed by the nam, then the euro. 

850 Temps: Comparing each of the three, gfs is by far the coldest, with the euro in the middle, followed by the very warm nam.

QPF: Nam is by far the wettest, followed by the gfs, and the euro. 

Talk about tough forecast. 

[mlgamer]

lol...18z ICON back to the south...

[Clinton]

1 minute ago, mlgamer said:

lol...18z ICON back to the south...

That's like 3 years worth around here lol.

[Jack_GradStudent]

ICON is a dream haha. If only lol. 

[Bellona]

3 minutes ago, someweatherdude said:

They all suck donkey balls.  Everyone on this forum has had a model give them a ton of snow only to have it go poof hours before it's supposed to start.  And everyone has been told by a model that the snow will miss them 24 hours out, only to get the snow.  The 2018 Thanksgiving weekend blizzard was supposed to hit Des Moines up til about 24 hours before it hit KC instead.  We can trash any given model, but the fact is that none of them is reliable under the classic definition of "reliable."    

At this point any of the solutions are still viable, and they differ enough to make a significant impact, or nothing. Might be one of those we don't know what's happening until it starts snowing. 

[The Snowman]

Omaha office gradually updating their data for the afternoon; point & click forecast now has 2-4" in Omaha, PoP chances increased from 60% to 90%. Imagine the afternoon set of snow graphics won't be much different from those a few hours ago.

[bud2380]

small shift north on the GFS.

 

[snowstorm83]

Euro has a tight gradient right through Lancaster county. Could be a situation where the airport (NW) gets 3" and SE Lincoln gets 6". My grids have 3-7" while WSW wording is 4-8". 

[The Snowman]

3 minutes ago, bud2380 said:

small shift north on the GFS.

 

Digging that look for the OMA-LNK area.

[james1976]

GFS gives me a couple inches this run compared to nothing on the 12z. Take what ya can.

[The Snowman]

For my fellow Nebraskans - 18z GFS total precipitation (left) alongside 12z GFS shows the scale of improvement for the Omaha area, snow-wise. Comparing with implied snow-ratio charts on Pivotal Weather, it looks as though this snow would be falling in 19:1 - 21:1 ratio territory (NWS Omaha notes 16:1 - 18:1 ratios in their latest AFD hot off the presses, however).

Assuming a 17:1 ratio and GFS verifying verbatim, this spells a 7" snowfall for Omaha; assuming a 20:1 ratio, it gives Omaha just over 8".

Still have quite a bit of ground to make up from recent southward model trends, but this is as good a sign as we can get here in the 18z runs. Baby steps.

[bud2380]

18z RGEM didn't get posted that I saw.

 

[bud2380]

DVN got much more robust with snow totals in their AFD.  My point forecast went from 3-5" to 4-8" with another 1-2" Saturday night.

 

At this time, the highest 
potential for these impressive snowfall rates looks to be south of I-
80. Snow ratios will obviously be increasing through the event as 
colder air infiltrates, possibly getting close to 20:1 in the heart 
of the heaviest snow. Went with WPC snow ratios, which generally 
range from 12 to 16:1 through the event. Latest snowfall amounts 
look to range from 8 to 10+ inches within the heaviest band, which 
currently looks to lie roughly along the US 34 corridor. Broader 
area surrounding that heavy band will see potential for 6 to 8" with 
the lowest amounts of 3 to 6" along the US 20 corridor.

[bud2380]

GEFS mean

 

[bud2380]

1. I like that DMX stated they will reduce the normal 6" in 12 hour criteria to 4" in 12 hours due to the strong winds, blowing and drifting snow and the first snowstorm of the season.  So expect winter storm warnings to run a county or two further north than normal.  They usually seem to issue warnings earlier than normal now, so I'm expecting them to be hoisted tomorrow morning, but I think it would be more prudent to wait until tomorrow afternoon since the snow won't start for most areas until Saturday AM or very late Friday night. 

 

 

Still expect 6+ inches of snow for a
large portion of southern Iowa and possibly central Iowa. This snow
will be fluffy and easy to blow around. Expect increasing wind of 15
to 25 mph with gusts over 35 mph at times will create significant
blowing and drifting of snow. Not blizzard criteria but still bad
given the first winter storm. Will default from typical 6" in 12 hr
criteria to 4" in 12hr along with sustained 25 mph wind and blowing
snow for warning upgrade decisions. Will have a partner webinar on
Friday at 11 am.

[Jack_GradStudent]

49 minutes ago, someweatherdude said:

They all suck donkey balls.  Everyone on this forum has had a model give them a ton of snow only to have it go poof hours before it's supposed to start.  And everyone has been told by a model that the snow will miss them 24 hours out, only to get the snow.  The 2018 Thanksgiving weekend blizzard was supposed to hit Des Moines up til about 24 hours before it hit KC instead.  We can trash any given model, but the fact is that none of them is reliable under the classic definition of "reliable."    

I was just more making a joke. I barely look into the ICON. 

[Clinton]

Here's the 18z GEFS ensembles 

[GDR]

GEFS went north

[Jaycee]

I’m happy the NAM is finally including Chicago! Im still nervous but we seem to be in a good spot overall. It’d be awesome if it was one of those storms that strengthens more than models were predicting, I’d love to see one of us get 12”+ out of this! 

[james1976]

DMX mentions that some solutions are showing shallower dry air intrusion allowing snow to edge a bit more north. Gonna be a sharp cutoff regardless. 

[Jack_GradStudent]

6 minutes ago, GDR said:

GEFS went north

Not sure what you're seeing. This is the QPF mean. 

[Hawkeye]

I'll likely guess the low end of the model snow range because my ratio always sucks when there is blowing and drifting.

[snowstorm83]

10 minutes ago, Jack_GradStudent said:

Not sure what you're seeing. This is the QPF mean. 

There was bump north on the northern edge for Nebraska/Iowa, prob what he meant. 

[tbone8]

[East Dubzz]

I'd say 1-3" is a solid prediction for this area at this point. My specific area, that is. 

[GDR]

16 minutes ago, snowstorm83 said:

There was bump north on the northern edge for Nebraska/Iowa, prob what he meant. 

You are correct!

[gabel23]

21 minutes ago, snowstorm83 said:

There was bump north on the northern edge for Nebraska/Iowa, prob what he meant. 

Yes there was; or at least it came in more juicy to the north affecting my area. I'm riding the fine line; northern part of the county looking at 1-2" while southern part of the county looking at 3 maybe 5". 

[Thunder98]

Garden City, KS is looking very cold on New Years Day. Could see highs around 10F and lows below zero!
 

 

[bud2380]

18z euro a little wetter 

[The Snowman]

Another model cycle, another comparison. 15z SREF vs. 09z SREF, QPF totals. Not totally sure what this precipitation orientation is, as the latest cycle gets rid of that heavier precip closer to Kansas City and instead spreads it seemingly all around. Fascinating to watch all of this guidance meander around as we move closer to the event.

[Clinton]

18z Euro is improving 

[Bellona]

Here James and I sit...in no man's land...lol

[jcwxguy]

[OttumwaSnomow]

After the slowest start to winter Ive ever experienced in the midwest,  run after run, model after model for several days consistently  has my part of se Iowa  in the sweet spot. I must admit being in the snow business  and a weather enthusiast it will be a unprecedented  letdown if this storm bust!

[Hawkeye]

1 minute ago, jcwxguy said:

We can probably cut 30% off the HRRR totals.  I'd certainly still take that.

[Andie]

We’re preparing for our New Year’s storm come Saturday night. A low of 23* expected and a High Sunday of 43*. Low again of 26*.  
Starting the year off right!!