January 11-13 Major Winter Storm/Blizzard

[hawkstwelve]

I can't make heads or tails of what's going to happen. We are about 30 hours out from the event getting underway out here and the NAM/HRRR/SREF have me at 10-12+ inches while the GFS/CMC/Euro all have me at or under an inch. I'm not sure I've seen such a wide spread of totals only being a little over 24 hours out.

My family is asking me if we are going to have snow tomorrow/Friday and I literally throw my hands up and say, "I have absolutely no idea. We will either get under an inch or we will get a foot" and they look at me like I'm crazy. 

[Pros3lyte]

Just now, hawkstwelve said:

I can't make heads or tails of what's going to happen. We are about 30 hours out from the event getting underway out here and the NAM/HRRR/SREF have me at 10-12+ inches while the GFS/CMC/Euro all have me at or under an inch. I'm not sure I've seen such a wide spread of totals only being a little over 24 hours out.

My family is asking me if we are going to have snow tomorrow/Friday and I literally throw my hands up and say, "I have absolutely no idea. We will either get under an inch or we will get a foot" and they look at me like I'm crazy. 

Lol my family is doing the same to me. 

[bud2380]

ARX (LaCrosse) also issued Winter Storm Watches all the way up to Red Wing, MN.  

[tStacsh]

GRR with a watch.  Comparing it to 2011 GHD storm for West Michigan.

 

- High impact storm likely Friday afternoon-Saturday morning

We will be issuing a Winter Storm Watch for the entire area for late
Friday morning through Saturday morning for heavy snow and
significant blowing and drifting snow. Confidence continues to
increase steadily for a high impact winter storm for the Friday-
Saturday time frame.

Models, including ensemble means, are in very good agreement
regarding the system, especially for 2-3 days out leading to the
increasing confidence. That said, there remain some smaller details
that could affect areas expected to be on the edge of the heavier
wintry precipitation.

The general pattern is pretty much set with a strong upper jet
streak and wave rounding the base of the long wave trough becoming
established over much of the country. The wave of note will be
lifting up, and closing off for very strong upward vertical motion
over the area. The associated sfc low looks to take a track over far
SE Lower MI, which would support a nearly textbook track for the
heaviest snow with the pivot point of isentropic ascent ahead of it,
and deformation/trowal area through the heart of the area, including
Grand Rapids.

The timing of the onset of the snow and heaviest snow has shown a
trend of just a little quicker. The problem with this is that it now
looks to impact the afternoon hours when schools are letting out and
as most people are heading home from work. There are indications
that the snow may become so heavy Fri afternoon and evening that
would could see 1-2"/hr snow rates for a few hours including those
impact times. Model ensembles are indicating probabilities as high
as 60-70% of a swath of snow over 12 inches, ensemble means also
pushing a foot.

In addition, we are looking at at least 30-40+ mph winds developing
at that time also. The snow does look to be somewhat wet in nature
at the onset, which would limit blowing and drifting snow initially.
The snow should become less wet, and blowing and drifting will
become a significant factor no later than Friday evening. This
system looks quite similar to the "Groundhog`s Day Blizzard" of
February 2011 where 10-14 inches of snow fell in 8 hours or so with
40 mph winds.

 

[bud2380]

My point forecast calls for 5-9".  I'm guessing the NWS is siding with the globals for right now.

 

Thursday Night

Snow, mainly after midnight. The snow could be heavy at times. Low around 20. Northeast wind 5 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 90%. New snow accumulation of 3 to 5 inches possible.

Friday

Snow. High near 28. Blustery. Chance of precipitation is 90%. New snow accumulation of 2 to 4 inches possible

[CentralNebWeather]

6 minutes ago, hawkstwelve said:

I can't make heads or tails of what's going to happen. We are about 30 hours out from the event getting underway out here and the NAM/HRRR/SREF have me at 10-12+ inches while the GFS/CMC/Euro all have me at or under an inch. I'm not sure I've seen such a wide spread of totals only being a little over 24 hours out.

My family is asking me if we are going to have snow tomorrow/Friday and I literally throw my hands up and say, "I have absolutely no idea. We will either get under an inch or we will get a foot" and they look at me like I'm crazy. 

I’m in a Winter Storm Watch for 3-7”. Some models show little to nothing. 

[Money]

NAM snowiest run yet for here 

[Hoosier]

16 minutes ago, indianajohn said:

WSW just issued for  NWI

I almost wonder if we'd be better off locally with the nuclear deepening scenario of the HRRR, but adjusted southward of course.  Would really kick that dynamic cooling into high gear.  The HRRR has northern IL snowing at 18z Friday, while the NAM is weaker and farther east with the surface low and yet it's still rain at that time.

[shakjen]

49 minutes ago, FV-Mike said:

Got to think  LOT will issue WSW this afternoon. 

Just did and they must not be buying into the northern shift. This last storm they waited until the day of to issue any headlines because they were worried about the NW shift and the rain mix. They haven't come out with the afternoon AFD yet explaining there reason.

[sholomar]

father lives in Ozaukee County, WI. Looks to get another good storm. However the 5 inches we just got won't melt until March or April anyways, whereas his couple of feet will be totally gone before my 5 inches, LOL.

While I was out jogging 5 miles, I got hit by a burst of moderate to heavy snow for about 20 minutes. That was quite enjoyable.

[shakjen]

2 minutes ago, shakjen said:

Just did and they must not be buying into the northern shift. This last storm they waited until the day of to issue any headlines because they were worried about the NW shift and the rain mix. They haven't come out with the afternoon AFD yet explaining there reason.

And the Lincoln office issued a WSW for their 4 northern counties already but DVN has not done anything for their counties

[FV-Mike]

4 minutes ago, shakjen said:

Just did and they must not be buying into the northern shift. This last storm they waited until the day of to issue any headlines because they were worried about the NW shift and the rain mix. They haven't come out with the afternoon AFD yet explaining there reason.

yep very interesting. Extended south through I80 even down to Kankakee

[hawkstwelve]

18Z RGEM trending snowier for here.

 

[Hoosier]

5 minutes ago, FV-Mike said:

yep very interesting. Extended south through I80 even down to Kankakee

Pretty excellent placement imo given the uncertainty.  Possible the southern tier struggles but possible that they don't.  

[bud2380]

DVN just issued Winter Storm Watches. 4-8” winds gusting to 45mph. 

[Hoosier]

The 3 km NAM flips to snow faster than the 12 km version (around here)

[Bumblin Bman09]

I like LOT WSW for NIL (near WISC border).  Based on current runs the 6+ seems accurate.  I don't think we exceed a foo but I think we end up in the 6-12 range.  LE as the storm moves east could help totals. 

[mlgamer]

9 minutes ago, sumweatherdude said:

I think it's appropriate that this looks like a giant phallus giving it to KC.  That's what usually happens.  I am, however, enjoying the posts from Iowa every 5 minutes telling us how good it's looking for them.  It's amazing how many different ways one person can say the same thing.  

I gotta admit...I laughed way harder and longer than I should have when I read this.  I had just posted mine in the complaint thread.

[East Dubzz]

[shakjen]

Lincoln AFD

the rain/snow line will shift as far north as Galesburg
around midday Friday with almost all of the forecast area
experiencing rain at that point. Colder air starts to filter in
from the west behind the low through the remainder of the day
Friday, though after forcing has peaked resulting in periods of
light to moderate snow. Forecasted snow totals have come down
substantially for much of the area. NBM probabilities for
exceeding 6 inches of snow during the event are highest (50-70
percent) across the far northern forecast area (Knox, Stark,
Marshall counties) where a Winter Storm Watch will be hoisted.

 

[hawkstwelve]

Woah. Surprised to see this just posted for here. I was not expecting a WSW yet...

IAZ001-MNZ089-098-SDZ059>062-064>069-110515-
/O.NEW.KFSD.WS.A.0002.240111T1800Z-240113T0000Z/
Lyon-Nobles-Rock-Davison-Hanson-McCook-Minnehaha-Douglas-
Hutchinson-Turner-Lincoln-Bon Homme-Yankton-
312 PM CST Wed Jan 10 2024

...WINTER STORM WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH
FRIDAY AFTERNOON...

* WHAT...Heavy snow possible. Total snow accumulations of 2 to 7
  inches possible. Winds could gust as high as 35 mph.

* WHERE...Portions of northwest Iowa, southwest Minnesota and
  south central and southeast South Dakota.

* WHEN...From Thursday afternoon through Friday afternoon.

* IMPACTS...Plan on slippery road conditions. Blowing snow could
  significantly reduce visibility. The hazardous conditions could
  impact the morning or evening commute. The cold wind chills as
  low as 25 below zero could cause frostbite on exposed skin in as
  little as 30 minutes.

[Grizzcoat]

8-14"

[Madtown]

Well I got the NAM on my side...with this thing neg tilt maybe ot can head north a bit more?

[CentralNebWeather]

WWA for 5” and 40 mph winds. Wind chills Friday night through Tuesday as low as -45. Wow. 

[hawkstwelve]

18z ICON did not blink. It stayed south with the heavier totals.

[gabel23]

14 minutes ago, Grizzcoat said:

8-14"

WOW. And what you have on the ground now??

[CentralNebWeather]

7 minutes ago, hawkstwelve said:

18z ICON did not blink. It stayed south with the heavier totals.

18z GFS is south

[hawkstwelve]

5 minutes ago, CentralNebWeather said:

18z GFS is south

Definitely stayed with its general southern solution. Although I do see a slight tick NW on the trend gif. Still keeps me at under an inch, so nowhere near the CAMs. 

[CentralNebWeather]

1 minute ago, hawkstwelve said:

Definitely stayed with its general southern solution. Although I do see a slight tick NW on the trend gif. Still keeps me at under an inch, so nowhere near the CAMs. 

Your right. Maybe I was comparing it to other northern solutions. 

[Grizzcoat]

16 minutes ago, gabel23 said:

WOW. And what you have on the ground now??

10"

[hawkstwelve]

Here's an excerpt from NWS FSD AFD. I was hoping they would dive into the model differences a bit more and give some reasoning on which solution they were leaning towards. They mention models being in "good agreement" but I can't say I agree with that considering they show anywhere from 0-12+ inches. But I guess with the WSW being issued for 2-7 they are hedging their bets on the Hi-res CAMs and their ability to pick up mesoscale forcing. They also mention potential upgrades to Blizzard Warnings depending on how things progress over the next few model runs. 

Of greater concern is a progressive, deepening storm system sliding
into Central Plains during this period. There has been a major
northwest shift in model snow accumulations in the past 24 hours,
toward increasing snow chances and amounts on Thursday through early
Friday. In our area, this means enhanced snowfall amounts from mid
level frontal banding and deformation as the attendant sfc low
tracks from the Oklahoma Panhandle toward the Ohio River Valley. As
a result, increased snow chances toward CONSAll as NBM was much too
low and prolonged higher snow chances longer through Friday.
Deterministic models (NAM, Euro, GFS) are in good agreement in snow
beginning in south central South Dakota Thursday morning and
spreading east through the day. An additional push of FGen induced
moisture/lift pushing north into the region Thursday evening,
bringing moderate to heavy snow to portions of northwest Iowa,
especially along and south of the U.S. Hwy 20 corridor.

Expected snowfall amounts have increased dramatically from 12 hours
ago. Have maintained 12z WPC liquid equivalent QPF which is notably
higher than most ensemble guidance, likely due to ensemble guidance
not resolving the assistance of mesoscale forcing for ascent we`re
expecting. This gives moderate to high confidence in a broad area of
6+ inches of snow south of a Spencer and Le Mars IA to Vermillion SD
line, where a Winter Storm Warning has been issued.

Further northwest, lower confidence in the snowfall forecast in
those areas from Spencer/Storm Lake to Le Mars to Vermillion and
northwestward toward Windom to Sioux Falls to Yankton. Thus have
issued a Winter Storm Watch for this area. Snowfall amounts could
certainly trend a few inches higher (7 or more inches) or lower
(as low as 2-3 inches) in this area, so have opted to maintain
the potential for expansion and/or upgrades to a warning after
another set or two of model runs.

Another major factor is how much of an impact Friday`s strong
northwest winds will have. With high confidence in gusts 25 to 40
mph during the daylight hours and continuing through Saturday,
locations that are still seeing snow falling through are likely
to see very difficult travel due to blowing and drifting snow.
There is still lower confidence regarding how long and at what
rates falling snow would occur through the day Friday. If snow
is no longer falling and winds are just lofting the new,
previously fallen snow, blowing snow may not cause as widespread
of travel issues. Given this uncertainty, will continue to
monitor potential for blizzard conditions and adjust headlines
as needed.

[Money]

GFS

GFS/NAM both showing 14-16 here now 

[bud2380]

GFS still looks great for my area.

 

[Money]

Icon also nearing a foot here and RGEM is about 8-9 

[shakjen]

1 minute ago, bud2380 said:

GFS still looks great for my area.

 

I would take that. But that is what the map looked for me for the last storm up until the day before, then I ended up on the rain/mix line.

[CentralNebWeather]

18z GFS. I’d take this with 40 mph winds. 

[CentralNebWeather]

18z ICON full 120 hours 

[hawkstwelve]

Anywhere from 0-3, 8-12, or 1-2 inches for a forecast valid starting 14 hours from now. Geez...

[Grizzcoat]

DMX-

 Blizzard anyone? (NW is the trend)

The big system in the forecast is still on track to impact the
region by late Thursday afternoon and through Friday night. This
system is trending further to the northwest that the forecast from
24 hrs ago as the upper level system closes off earlier and leads to
this system. Highlights (or low lights, pending your perspective) of
this system include as strong low level moisture transport northward
from the Gulf. This system will have a strong push of theta-e
advection followed by the development of a TROWAL feature as warm
air and moisture wrap around the system. The TROWAL may result in an
enhanced region of banded heavy snowfall. Convective properties are
possible with this system and there is a better signal for slantwise
convective potential into central Iowa along with general elevated
convection possibly reaching the far southeast. Finally, snow
crystal morphology is trending dendritic with along with the
dendritic growth zone region deepening as colder air arrives
therefore, snow to liquid rations will be near to above climatology.
All in all, pending the exact track of this storm, another system
with warning criteria potential snowfall, with an a greater than
50% chance of heavy banded snow along the TROWAL should it set up
over Iowa as progged. The Arctic cold will begin to filter into Iowa
during this evening with increasing cold advection. This coupled
with a strong pressure gradient and mixed layer winds will lead to
the potential for wind gusts of 40 to 50 mph mainly later Friday and
Friday night. Given the current snow cover in place and storage
areas already partially full, blowing snow will be a greater impact
than this past event. Worst case scenario, this could turn into a
Blizzard. For now will highlight significant snow and blowing snow
possible. Will be issuing a Winter Storm Watch for Thursday night
through Friday evening for the entire area. Will continue to provide
higher resolution of timing and location as confidence increases.

[hawkstwelve]

This trend gif of the past four runs shows the NW trend on the GFS a bit better.

I'd expect one of the model camps to break towards the other on the 00z runs tonight. I'll be waiting with bated breath...