New Year’s Hard Cutter

[OKwx2k4 4169]

5 hours ago, Jack_GradStudent said:

The latest nam's track is pretty good for the kc area, but it seems the heaviest precip bands will be on the edges of the precip shield-- I feel like that is fairly common in these type of storms. We need the track to be just a bit stronger and further east and south, and that would put us in the best chance for 6+ inches of snow. 

It's interesting, though, the track at least. It jumps almost straight north into the northeast corner of OK and then starts making a sharper northeast turn into central Missouri-- this will interesting to track on Satellite as it happens.  

Going to be a unique and memorable storm if it pulls that off. (Track jump)

One of the hardest cutters I've seen in a model.

[Tom 16608]

Interesting, both the 00z UKIE/EURO have shifted SE in track and laying down a swath of SN from E KS/MO into Lower Lakes...most of the SN in N ILS WI/MI is from the recent storm...deduct the amount below from the second image...

 

 

00z Euro...less generous in IL/IN/S MI...

 

00z Canadian...

 

[Tom 16608]

00z EPS follows the SE trend...not only do we see the models picking up on a weakening SLP as it tracks towards the Lower Lakes, the "kicker" storm tracking into the PAC NW and riding down the west coast into AZ/NW from the 31st into the 1st of the new year, ends up following a similar track on the heals of the New Year's system which could be another "surprise" piece to this very complex system.  I'm seeing many more ensemble members showing this Upper Level feature tracking across TX/OK into MO/IL/IN through the 2nd/3rd of Jan that could lay down a few inches of additional snow.

 

Looking better for KC folks into SE IA/S WI and parts of N IL...as well as, into S MI...

 

 

 

[Clinton 4318]

0z Euro comes in a little colder and further south.  Stoll to much ice in mby

[Clinton 4318]

Watch issued.

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

* WHAT...Heavy mixed precipitation possible. Total snow
  accumulations of 1 to 3 inches and ice accumulations of up to
  three tenths of an inch possible.

* WHERE...Portions of east central and northeast Kansas and
  central, north central, northeast, northwest and west central
  Missouri.

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

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the morning or evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor t

[Clinton 4318]

This mornings AFD

With the departure of one system, attention quickly shifts to the
next system deepening across northern Mexico.  This system is
expected to have a unique track moving from southern Texas into the
southern and central plains as upper ridge across the southeastern
US prevents little eastward movement.  Models have come into better
agreement on the trajectory of this system over the past 12-24
hours, with good agreement of quickly deteriorating conditions
late on New Years Eve and continuing into New Years Day. This
system seems to have a wealth of warm air aloft near 850 mb ahead
of the system leading to mixed precipitation for at least the
first half of the event. Expect non diurnal temperatures Thursday
night into Friday morning as strong warm air advection leads to
isentropic lift expanding from south to north. Near surface layer
should evaporatively cool as the precipitation begins, locking
cooler air in near the surface at least initially. Strong
inversion should keep the favored precipitation type in liquid
form, but with surface temperatures sub freezing, could be looking
at another icing event around the region. Models show fairly
significant cooling ~850 mb in the 12-18Z time frame on Tuesday as
upper low approaches from the south. If this cooling occurs,
precipitation will likely try to switch over to snow. Am a bit
concerned that the amount of cooling may be a bit overdone, which
could potentially lead to even more ice than models are
suggesting. Models are alos hintng at inverted trough type
feature, so should be interesting to see how the thermal structure
of this system evolves.

NAM and GFS suggest potential for 0.25 -0.50"+ of ice across much of
the forecast area. WPC WSO page suggests 30-50+% of exceeding a
quarter of an inch of ice, with the greatest focus along and south
of a line from St. Joseph to Kirksville.  With impacts expected on
holiday and being significant, collaborated a winter storm watch
with surrounding offices to the west.

This system is expected to exit to the northeast late on New Years
Day as low moves north of ridge across the southeast and becomes
more influenced by the prevailing westerlies.

The active pattern is expected to continue into Saturday as a second
system follows on the heals of the New Year`s Day system.  This
system is expected to be influenced by an unusually strong southern
branch of the upper jet.  As system deepens and becomes better
organized, could see light snow develop across central and eastern
Missouri.  Through collaboration with southern and eastern
surrounding offices, raised pops to 75% of guidance values.  With
cloud, and lingering low level cold air advection, have also reduced
high temperatures on Saturday.

Southern branch of the upper jet is expected to weaken next week,
potentially leading to quieter weather across Missouri.  With that
said, northern branch of the jet becomes dominant and a series of
waves are expected to move across the northern half of the US.  For
now, have stuck close to the blend which suggests a warming trend to
above normal levels by early-mid week.

[Clinton 4318]

6z RGEM (yes please)

 

[Clinton 4318]

6z ICON and GFS

[Tom 16608]

3 minutes ago, Clinton said:

6z RGEM (yes please)

 

The Canadian’s leading the way...again???  If today’s 12z runs continue to show the SE shift, I’ll be more comfortable with my chances of seeing SN.  

[Clinton 4318]

7 minutes ago, Tom said:

The Canadian’s leading the way...again???  If today’s 12z runs continue to show the SE shift, I’ll be more comfortable with my chances of seeing SN.  

When I read my offices AFD this morning and they referenced only the GFS and NAM all I could do was shake my head.  No mention of the Euro or CMC.

[Clinton 4318]

Good trends: 6z Euro trends colder.  I think we've seen this before.

[james1976 3934]

Sucks that it turns east so quickly

[East Dubzz 1312]

Guess it’s time to turn the attention to this one, though my expectations are basically zilch at this point. Would be nice to pick up a couple extra inches of snow, though.

[snowstorm83 1906]

26 minutes ago, james1976 said:

Sucks that it turns east so quickly

Like it shoots north and then I-80 pushes it down 

[Clinton 4318]

Just looked at last nights UKIE.  It sure is different than the other models.

[MIKEKC 409]

Beautiful day yesterday in KC north. We started as snow, quite heavy at times, then sleet, then snow, then sleet, then heavy freezing rain, then snow, then heavy sleet. Followed by heavy rain that put .25 inches of ice on my trees.  End result, a mess on the roads especially north of the MO river. Another huge bonus, over 1 inch of moisture throughout the city and widespread. WE NEEDED IT! So, as a snow contractor, my fleet had to apply multiple rounds of salt yesterday...$$$$$

The data from several models had us rising to the 40's to get rid of the ice on the trees and streets, we only made it to 33 in KC north and we have a heavy layer of ice on everything this morning. I would call this a mini ice storm for the north side of KC. 

Now, round two coming and it could be bigger for KC. We'll see! tracking the data, look forward to all the maps. Keep them coming Clinton. (I like the UKMET, that benefits both of us....colder solution) I'm with you, not a fan of ice. 

 

 

 

[Niko 7225]

All models are trending way SE w this one and colder. Even Euro is on board.

[Clinton 4318]

12z GFS trended colder but weaker and more icy.

[james1976 3934]

Des Moines with an interesting write up. Mentions the NAM and a more north solution. And even thundersnow! I still think this misses me though.

The primary forecast challenge this forecast period is the the
closed low lifting north from northern Mexico and toward central
Missouri. While this is unusual, there is a relatively stout sub-
tropical high from the eastern Gulf and into the Caribbean, forcing
the upper low to the north. There are a plethora of complexities
with this system which is causing havoc on predicting precipitation
types and amounts. The system does have an impressive yet focused
warm conveyor of moisture wrapping around the parent low with PWATs
increasing to above 0.5 inches. The northern edge will have some
erosion due to very dry air on the north edge from high pressure. At
this time, it does appear that southeast Iowa will get into the
region of a wintry mix with snow and freezing rain possible. The GFS
ensembles hold this precipitation farther to the south while the
deterministic NAM and the ECMWF ensembles are farther north. Given
the amount of forcing associated with this system, precipitation
loading with strong forcing tends to lead to accumulations farther
north than models tend to suggest. How far north the mixed
precipitation gets is in question as much of the warm layer exists
in the very dry layer and precipitation loading and subsequent
evaporative cooling could drive these warmer temperatures down with
the result being snow. A deep isothermal layer just below 0C does
look likely which could lead to aggregate snow crystal development,
ie larger sticky/heavy(in weight)snowfall with snow liquid ratios in
the 8-10 to 1 range. Finally, the strong forcing and steepening mid-
level lapse rates could again lead to areas of convection and
potentially thunder snow. Currently have a snow band in the 2 to 4
inch range which is a good medium at this point with how complex
this system is.

[jaster220 8336]

54 minutes ago, Clinton said:

Just looked at last nights UKIE.  It sure is different than the other models.

Yeah, not sure it can get that cold and snowy. Sure would be nice tho up this way as well as down your way.

[Clinton 4318]

1 minute ago, jaster220 said:

Yeah, not sure it can get that cold and snowy. Sure would be nice tho up this way as well as down your way.

CMC looks great.  

[Clinton 4318]

2 minutes ago, jaster220 said:

Yeah, not sure it can get that cold and snowy. Sure would be nice tho up this way as well as down your way.

Any chance the snow pack across Neb and Iowa is working in my favor today?

[jaster220 8336]

Didn't want to say it before, but in all my decades of watching storms around here, the 2nd system on a 2-parter like this always goes east of the first one. Ofc, there's gonna be somebody hoping for a double hit and some over-lap is certainly still in play. But the idea that this SLP was going to end up in N Iowa or MN was total junk modelling.

[Clinton 4318]

12z CMC.  I would except this.

[mlgamer 494]

This more and more looks like a 1-4" WWA snow event for most of KS and MO that gets any snow. The big question is how much ice accumulates and does that require a warning or advisory. Also could be a sleetfest for some. I'm guessing a 12 hour or less event for most folks. Unless ice becomes a major problem, this system will likely be just your average lower-end winter weather event. I guess beggars can't be choosers...lol

[St Paul Storm 4012]

3 minutes ago, jaster220 said:

Didn't want to say it before, but in all my decades of watching storms around here, the 2nd system on a 2-parter like this always goes east of the first one. Ofc, there's gonna be somebody hoping for a double hit and some over-lap is certainly still in play. But the idea that this SLP was going to end up in N Iowa or MN was total junk modelling.

Agree 100%. There was no way this was going to move north, or even retrograde. Pure garbage from the models a day or two ago. 

[Tom 16608]

7 minutes ago, Clinton said:

12z CMC.  I would except this.

Co-sign!

[MIKEKC 409]

UKMET and CMC are worrying me...Don't trend too far SE.

 

[Clinton 4318]

18 minutes ago, mlgamer said:

This more and more looks like a 1-4" WWA snow event for most of KS and MO that gets any snow. The big question is how much ice accumulates and does that require a warning or advisory. Also could be a sleetfest for some. I'm guessing a 12 hour or less event for most folks. Unless ice becomes a major problem, this system will likely be just your average lower-end winter weather event. I guess beggars can't be choosers...lol

I think there will be a heavy band of snow just west of the ice/snow line.  Too much moisture for there not to be.  I also question if the storm will move through our area as fast as being modeled.

[someweatherdude 386]

Seems like NAM, GFS and CMC (and some others) have all pretty much come into line on a path for the heaviest snow.  They're all heavily dependent on a razor thin margin of error on the thermals though.  

[GDR 667]

Gfs with a lot of ice for the folks south

[Tom 16608]

12z UKIE suggesting the SE ain't done yet...a colder storm on the N/NW side of the system...

@Clinton, UKIE saying all snow...

 

 

 

 

 

Total snowfall including the secondary ULL feature that the models are picking up on...adds an additional few inches in spots...

 

[Clinton 4318]

12z Ukie is so far SE that I'm on the NW edge of heavy snow.  Good for S. Mich

[Clinton 4318]

3 minutes ago, Tom said:

12z UKIE suggesting the SE ain't done yet...a colder storm on the N/NW side of the system...

@Clinton, UKIE saying all snow...

 

 

 

 

 

Total snowfall including the secondary ULL feature that the models are picking up on...adds an additional few inches in spots...

 

Thats great but no further SE!!!!!

[Tom 16608]

1 minute ago, Clinton said:

Thats great but no further SE!!!!!

I think your in a good spot with this one...let's see what the Euro shows in a few.  I gotta feeling it'll show something similar.  

[Clinton 4318]

3 minutes ago, Tom said:

I think your in a good spot with this one...let's see what the Euro shows in a few.  I gotta feeling it'll show something similar.  

This would be a great way to ring in the new year.

[Tom 16608]

12z Euro with a nasty freezing rain to heavy snow scenario for E KS/KC....

[Clinton 4318]

3 minutes ago, Tom said:

12z Euro with a nasty freezing rain to heavy snow scenario for E KS/KC....

Warning level event for sure.

[Clinton 4318]

15 hours of frz rain before it changes to snow in mby.

[Tom 16608]

1 minute ago, Clinton said:

Warning level event for sure.

It's rather amazing how the Canadian has been rock steady for both systems and now the rest of the models are trending towards this storms solution.  Kuddo's to the Canadian's if this pans out again! Oh Canada....

[Black Hole 725]

12z ECMWF Kuchera snow, sleet, and ZR accumulations. 

[Tom 16608]

1 minute ago, Clinton said:

15 hours of frz rain before it changes to snow in myb.

Not a fun scenario at all...I still think this strong ULL will produce it's own cold air just enough that it'll remain snow.  The track is perfect for your region.  You always want to be on the NW side and your right there.  If you were to show me this ULL track in early Jan any other year, I'd say bullseye for you is no question.

 

[Clinton 4318]

1 minute ago, Tom said:

Not a fun scenario at all...I still think this strong ULL will produce it's own cold air just enough that it'll remain snow.  The track is perfect for your region.  You always want to be on the NW side and your right there.  If you were to show me this ULL track in early Jan any other year, I'd say bullseye for you is no question.

 

Are we getting good sampling with the energy diving fairly deep into Mexico right now?

 

[Tom 16608]

1 minute ago, Clinton said:

Are we getting good sampling with the energy diving fairly deep into Mexico right now?

 

Yes and No...I'd like to wait till tomorrows 12z runs to see how this storm begins to develop deep down in TX...

[Tom 16608]

3 minutes ago, Clinton said:

Are we getting good sampling with the energy diving fairly deep into Mexico right now?

 

Keeping a close eye on that secondary piece that is riding on the heels of the main ULL...looks like it drops a couple inches in MO and up this way.  Back to back days with snow falling???  #winning2021

[hlcater 1321]

Whew this system really crapped out. Looking like maybe a 1-2” system here optimistically. Not gonna complain tho. 

[Jack_GradStudent 30]

After looking at this morning's data I have a few thoughts (for the KC area): 

1) I think the majority of the metro (with the exception of maybe areas to the Southeast like Lee's Summit) will remain below freezing and we will see a freezing rain event, transitioning to sleet, and then snow. 

2) QPF's will increase as you move south and southeast from St. Joe. I think the GFS shows this potential well. 

3) Among the areas that remain below freezing for the entirety of the storm, the most likely areas for the most ice is to the south of the City. I think the GFS does a good job of portraying this potential as well. 

4) The biggest question: When will the temperatures in the 800-900 mb layer go below freezing? 

This is the 850 mb valid at 9 a.m. Areas in the blue outlined by the white line are below freezing. You can see this happening first south and west of the City. These are the areas that will characterized by the most snow. This detail is so huge and so tiny and that is why snow totals are going to be hard to predict. 

This is an odd storm, so odd things may happen. A couple of other notes:

- I'm noticing in the ensembles a trend of snow going back to freezing rain as the precip lightens up as it is moving away. 

- There is a snow pack in Iowa that could push the baroclinic zone further south. 

- This storm due to heavy precip rates and its strength could generate its own cold air. 

Final thoughts: 

Ice: 0.3-0.6 of freezing rain expected resulting in 0.1-0.3 inches of Ice-- up to a half inch of Ice south and east of KC

Snow: 1-4 inches of snow, potential for 6-8 inches of snow west and southwest of the City (Topeka, Emporia)

Would love to know what you guys think!

Jack 

[Clinton 4318]

19 minutes ago, Jack_GradStudent said:

After looking at this morning's data I have a few thoughts (for the KC area): 

1) I think the majority of the metro (with the exception of maybe areas to the Southeast like Lee's Summit) will remain below freezing and we will see a freezing rain event, transitioning to sleet, and then snow. 

2) QPF's will increase as you move south and southeast from St. Joe. I think the GFS shows this potential well. 

3) Among the areas that remain below freezing for the entirety of the storm, the most likely areas for the most ice is to the south of the City. I think the GFS does a good job of portraying this potential as well. 

4) The biggest question: When will the temperatures in the 800-900 mb layer go below freezing? 

This is the 850 mb valid at 9 a.m. Areas in the blue outlined by the white line are below freezing. You can see this happening first south and west of the City. These are the areas that will characterized by the most snow. This detail is so huge and so tiny and that is why snow totals are going to be hard to predict. 

This is an odd storm, so odd things may happen. A couple of other notes:

- I'm noticing in the ensembles a trend of snow going back to freezing rain as the precip lightens up as it is moving away. 

- There is a snow pack in Iowa that could push the baroclinic zone further south. 

- This storm due to heavy precip rates and its strength could generate its own cold air. 

Final thoughts: 

Ice: 0.3-0.6 of freezing rain expected resulting in 0.1-0.3 inches of Ice-- up to a half inch of Ice south and east of KC

Snow: 1-4 inches of snow, potential for 6-8 inches of snow west and southwest of the City (Topeka, Emporia)

Would love to know what you guys think!

Jack 

Thank you very much for the breakdown, it was well thought out and you very well may be correct with your forecaTst.  The only thing I would say is that as of today I don't trust the GFS with thermals.  My hope is that it will be colder at the 800-900mb level.  My fear is that it won't be and it will be colder at the surface than what the GFS shows.  Hoping the snow pack to the north can throw me a bone.

[Clinton 4318]

12z GFS EPS and CMC mean

[someweatherdude 386]

8 minutes ago, Clinton said:

12z GFS EPS and CMC mean

One slightly north and west of KC, one right over KC and one slightly south and east of KC.  Be nice (for me) if we could just split the difference.  Again, thermals are the wildcard no matter where the heaviest precipitation falls.  WS Watch posted for KC area, but only talking 1-3" snow.