MN/ND Snow Event Nov 21/22

[baroclinic_instability]

It is getting close enough to the event I feel a new thread should be started regarding the snow event setting up for late this weekend. I have seen enough of these events to be impressed with what I am seeing thus far. Model guidance is mainly up in the air regarding the ejecting shortwave off the west coast trough but more or less pretty similar in the thermal fields. Amplitude wise, the CMC and Euro are stronger with more impressive frontal banding on the cold side of this storm. Even the weaker and lower amplitude GFS would yield 2-4 inch snowfalls through much of northern ND and MN. Snow factors look good and much of the forcing will be through the 800-600 hpa layer on the cold side of the baroclinic zone with a very favorable coupled upper level jet pattern. GEM/Euro could yield 6-7+ in snow totals, especially heading into northern MN.

Images coming later...just want to get the thread started.

For now, I am trending more towards the earlier higher amplitude solutions (EURO/CMC) with the ejecting shortwave mainly because the strength of the baroclinic zone. The GFS makes me scratch my head a little with its total lack of amplification as the wave progresses NE until it is well into Canada. Moreover higher amplified solutions will progress slower and will increase both the frontal banding and longevity of the snowfall.

[mnweather]

It is getting close enough to the event I feel a new thread should be started regarding the snow event setting up for late this weekend. I have seen enough of these events to be impressed with what I am seeing thus far. Model guidance is mainly up in the air regarding the ejecting shortwave of the west coast trough. Amplitude wise, the CMC and Euro are stronger with more impressive frontal banding on the cold side of this storm. Even the weaker and lower amplitude GFS would yield 3-5 inch snowfalls through much of northern ND and MN. Snow factors look good and much of the forcing will be through the 800-600 hpa layer on the cold side of the baroclinic zone with a very favorable coupled upper level jet pattern. GEM/Euro could yield 6-7+ in snow totals, especially heading into northern MN.

Images coming later...just want to get the thread started.

This one should be good. It will be my first snow of the year I believe next to the big lake. Everything has been rain thus far. Do you think snow as well next to Lake Superior?

[baroclinic_instability]

This one should be good. It will be my first snow of the year I believe next to the big lake. Everything has been rain thus far. Do you think snow as well next to Lake Superior?

Good question, areas right along the shore may not get much except a heavy wet snow. I will have to look more. Best snow looks farther north though. Areas in the higher elevations of the arrowhead will stay colder with better snow accumulations on the cold side of the of this storm.

[mnweather]

At least it looks promising for a good snow somewhere around here. Thanks!

[cmichweather]

It is getting close enough to the event I feel a new thread should be started regarding the snow event setting up for late this weekend. I have seen enough of these events to be impressed with what I am seeing thus far. Model guidance is mainly up in the air regarding the ejecting shortwave off the west coast trough but more or less pretty similar in the thermal fields. Amplitude wise, the CMC and Euro are stronger with more impressive frontal banding on the cold side of this storm. Even the weaker and lower amplitude GFS would yield 3-5 inch snowfalls through much of northern ND and MN. Snow factors look good and much of the forcing will be through the 800-600 hpa layer on the cold side of the baroclinic zone with a very favorable coupled upper level jet pattern. GEM/Euro could yield 6-7+ in snow totals, especially heading into northern MN.

Images coming later...just want to get the thread started.

Yup everyone is excited here at UND for the field project, only problem looks like it may be an overnight event starting late saturday for us i hope i'm not assigned DOW duty. I'm thinking at least a few inches for right now but i hate to say it but for how early it is we actually are gonna have some pretty decent snow ratios with this cold air even though its still november. I'm pretty sure the UND polarimetric radar will be spinning during the event so hopefully it'll be working on the webpage and updating i'll send a link to the thread if it is up and running during the snow, if you guys want i can link the SNOwD UNDER forecasts and model page using a local wrf, we have a facebook page http://www.facebook.com/snowdunder and blog http://snowdunder.blogspot.com/ we'll pretty much be interested in any type of winter precip in the northern plains. We are using 1 DOW truck along with the und polar. radar and also flying our research aircraft and will have teams doing hourly observations of precip rates to do a study on winter time precip in the red river valley region.

[baroclinic_instability]

Yup everyone is excited here at UND for the field project, only problem looks like it may be an overnight event starting late saturday for us i hope i'm not assigned DOW duty. I'm thinking at least a few inches for right now but i hate to say it but for how early it is we actually are gonna have some pretty decent snow ratios with this cold air even though its still november. I'm pretty sure the UND polarimetric radar will be spinning during the event so hopefully it'll be working on the webpage and updating i'll send a link to the thread if it is up and running during the snow, if you guys want i can link the SNOwD UNDER forecasts and model page using a local wrf, we have a facebook page http://www.facebook.com/snowdunder and blog http://snowdunder.blogspot.com/ we'll pretty much be interested in any type of winter precip in the northern plains. We are using 1 DOW truck along with the und polar. radar and also flying our research aircraft and will have teams doing hourly observations of precip rates to do a study on winter time precip in the red river valley region.

yeah I hear ya, I do think a few inches will be on the very low end though. I re-updated the initial post with my further thoughts. GFS seems too low amplitude and fast with the shortwave. I will be early though, you should get yourself on DOW if you can!

[cmichweather]

yeah I hear ya, I do think a few inches will be on the very low end though. I re-updated the initial post with my further thoughts. GFS seems too low amplitude and fast with the shortwave. I will be early though, you should get yourself on DOW if you can!

lol ya the DOW sound like fun except they've decided to lump the overnight into 1 huge block of time, i'd rather do a few hours of radar spinning then head home, only so much you can scan for in snow event, not like we are going to see some huge deformation area with extreme banding structure. I agree on the low end scale though i'm just hedging 2 inches or so this far out, i think its a solid 4-6 inch event over a 24 hour period nothing extreme but a nice early season event.

[baroclinic_instability]

6Z GFS is in, and as I thought, it has trended ever so slightly more towards the Euro/CMC more amplified solutions, and is also slightly slower as a result.

Note how the low amplitude shortwave is now more amplified over northern MN at the same time. I still think a good snow event is in order for northern MN/ND with some 4-7 inch amounts, especially near the Canadian border.

I will add more dynamic thoughts with the arrival of the 12Z runs.

0Z GFS

06Z GFS

[mnweather]

12Z NAM looks further north.

[baroclinic_instability]

12Z NAM looks further north.

I will say with this storm, the NAM is garbage and is not being used for reasons I will explain later. Note that it is phase shifted considerably compared to the GFS in its height field.

[baroclinic_instability]

Here is a typical example of the NAM phase shift. It is easy to spot because it will be 3-6 hours too slow, and the entire height field is phase shifted, not just one feature. Compare at 60 hours.

NAM:

http://www.twisterda...e&archive=false

GFS:

http://www.twisterda...e&archive=false

It is easy to see if you click back and forth between the two.

It is a common problem, and when you see this as a forecaster, I just avoid it until it corrects the problem.

[mnweather]

Do you still think a good swath of snow for my area north of Duluth. I was thinking 2-6" maybe. What are you feelings on possible lake enhancement with this system?

[baroclinic_instability]

Do you still think a good swath of snow for my area north of Duluth. I was thinking 2-6" maybe. What are you feelings on possible lake enhancement with this system?

Where are you and at what elevation? I still think the better accumulations will be in the higher terrain closer to the international border where the snow factors will be more impressive, 4-6 in range, decreasing quickly as you head south away from the upper level front. Definitely will be some lake enhancement next to the shore, especially as you uplift into the higher terrain. Still though, can't put details down quite yet as the main shortwave in question is still off the west coast. It does seem the track has shifted very slightly north though. We will see if that is a meaningful trend. International border and just south still looks very good, may not see much in Duluth.

[mnweather]

I might not see much then. I guess it is just a wait and see type thing.

[tacoman25]

Hopefully a nice snowpack laid down at the onset to maximize the low temps with this airmass.

[baroclinic_instability]

I might not see much then. I guess it is just a wait and see type thing.

Yeah not looking as good now for you, if you are just north of Duluth prolly hardly anything.

[mnweather]

Yeah not looking as good now for you, if you are just north of Duluth prolly hardly anything.

Are you thinking of mixing issues for the area versus all snow further north?

[baroclinic_instability]

Are you thinking of mixing issues for the area versus all snow further north?

That is a possibility, but I think it should stay mostly snow, just a wet snow. I just think you are too far away from dominant forcing, cold air, and moisture.

[mnweather]

What area do you think sees the most snow and how much?

[prinsburg_wx]

What area do you think sees the most snow and how much?

The 2nd event on Nov 22 (monday/monday night) is looking more promising according to the euro/ggem or we talking about the same event???

[mnweather]

The 2nd event on Nov 22 (monday/monday night) is looking more promising according to the euro/ggem or we talking about the same event???

I am thinking of the one on Sat. night/Sunday but how much are you thinking for northen MN on the north shore for the Monday system?

[baroclinic_instability]

The 2nd event on Nov 22 (monday/monday night) is looking more promising according to the euro/ggem or we talking about the same event???

No, different ones. The first shortwave this weekend is what we are discussing. The second will be interesting too. Good news is everyone in MN should manage snow from at least one of the two!

[prinsburg_wx]

I am thinking of the one on Sat. night/Sunday but how much are you thinking for northen MN on the north shore for the Monday system?

maybe baroclinic_instability will comment on this 2nd event after we get through the 1st but here's what ggem qpf looks like with the 2nd system....a good event i think.

[Hoosier]

maybe baroclinic_instability will comment on this 2nd event after we get through the 1st but here's what ggem qpf looks like with the 2nd system....a good event i think.

Where are you getting those graphics from?

[prinsburg_wx]

Where are you getting those graphics from?

i make my own using gempak

[mnweather]

maybe baroclinic_instability will comment on this 2nd event after we get through the 1st but here's what ggem qpf looks like with the 2nd system....a good event i think.

It does look pretty impressive.

[baroclinic_instability]

maybe baroclinic_instability will comment on this 2nd event after we get through the 1st but here's what ggem qpf looks like with the 2nd system....a good event i think.

Still got to get through the first. The models, as I had expected, are having huge issues with the breakdown of the first wave and where exactly it ejects. Throw in a complicated coupled jet pattern over the arrowhead, which the models have been consistent with, and there is still hope for areas slightly farther south than I previously believed. The NAM is spitting out some seriously non-synoptic vertical velocity fields associated with a mesoscale jet circulation. Hence the heavy area of qpf over the arrowhead.

The forecast jet pattern:

GFS vertical velocity fields associated with the mesoscale jet circulation:

and NAM:

What we are essentially dealing with here is the "breakdown" of the large scale west coast trough and a series of shortwaves (circled green). This is a highly sensitive process that models struggle mightily with, enough so you will see huge model flip-flops run by run. Essentially this is the opposite of wave phasing (trough mergers), and as most mets know, models struggle with low amplitude waves phasing with a larger trough. Moreover, the trough is still off the west coast. As a met, best I can say is there is still potential over much of the arrowhead, but the combination of the variability in how each successive shortwave is ejected off the main trough and the mesoscale circulations associated with that jet pattern make it impossible to call with any certainty at this point.

SREF guidance trends are usually more useful at this point than individual model runs, at least until the ejecting shortwave is within the sounding network over land.

[prinsburg_wx]

Still got to get through the first. The models, as I had expected, are having huge issues with the breakdown of the first wave and where exactly it ejects. Throw in a complicated coupled jet pattern over the arrowhead, which the models have been consistent with, and there is still hope for areas slightly farther south than I previously believed. The NAM is spitting out some seriously non-synoptic vertical velocity fields associated with a mesoscale jet circulation. Hence the heavy area of qpf over the arrowhead.

The forecast jet pattern:

GFS vertical velocity fields associated with the mesoscale jet circulation:

and NAM:

What we are essentially dealing with here is the "breakdown" of the large scale west coast trough and a series of shortwaves (circled green). This is a highly sensitive process that models struggle mightily with, enough so you will see huge model flip-flops run by run. Essentially this is the opposite of wave phasing (trough mergers), and as most mets know, models struggle with low amplitude waves phasing with a larger trough. Moreover, the trough is still off the west coast. As a met, best I can say is there is still potential over much of the arrowhead, but the combination of the variability in how each successive shortwave is ejected off the main trough and the mesoscale circulations associated with that jet pattern make it impossible to call with any certainty at this point.

SREF guidance trends are usually more useful at this point than individual model runs, at least until the ejecting shortwave is within the sounding network over land.

Thanks for the detailed analysis...much appreciated.

[mnweather]

I now have likely pops in my area for Sat night/Sunday with a mix possible. The Monday system has chance pops but DLH mentions accumulation from Brainerd to Dulth on north.

[baroclinic_instability]

This thread has died a little but I thought I would revive it since it is more than likely that a decent snowfall event is likely with this system across northern ND and into northern MN, although the latter is more up in the air. It seems there will be some heavier mesoscale banding with the aforementioned upper level coupled jet and strong warm air advection through 850-650 hpa pretty much over the same small region--in other words, low level forcing will be over a rather narrow region and enhanced through a narrow zone with potential for better than good snowfall, it seems 3-4 band likely with 6-7+ possible in a narrow corridor somewhere near or just north of GFK where the snow factors will be pretty decent through the aforementioned 850-650 zone--good for you SNowdUnder guys. NAM sucks, but as I expected, is shifting southward as it continues to fix its "phase-shifting" problem alluded to earlier. I have a feeling GFK will begin lofting the WW Advisory for northern counties soon, GFK after all 0Z guidance is in. Don't be surprised to see a few Winter Storm Warnings to come up during this event once it gets going and they can better locate areas of heavier banding,