December 21st-24th, 2022 | Plains/MW/GL/OV Winter Storm

[Hiramite]

I haven't read other APD's, but for us Ohio folks, this is what CLE said about the source of snow.  They don't have much hope/faith in the wrap-around producing.

...snow early Friday morning into Friday evening, with the precipitation along the front being the main driver for accumulations.

[Columbusbuckeye]

40 minutes ago, Ohiobuckeye45 said:

I definitely buy this, but my problem with the elevation theory is its not really a factor this go round, pretty much everyone is going from 35 to 10 in a matter of minutes so I doubt the extra 5 minutes maybe of changeover Bellefontaine gets over Columbus is meaningful to the tune of nothing vs. 2-3''. However like you said just because its modeled like that doesn't make it valid. I JUST NEED TO KNOW lol

I think the elevation plays a factor with lake enhancement and that’s what the models are skewing towards with these totals.  

[Wnwniner]

1 minute ago, Columbusbuckeye said:

I think the elevation plays a factor with lake enhancement and that’s what the models are skewing towards with these totals.  

I've noticed the models have consistently had fingers of N/S oriented bands in the central Ohio area the last few days; I assumed it was due to the changeover and how much precip was being modeled in the area at that time.  The last few images have really made it more of a dry slot than fingers of heavier snow.

[Hiramite]

LOL

(If you can't read what Jerry is saying..."List of Hazardous Conditions")

[MesoscaleBanding]

Anyone have the 18z Euro?

[BuckeyeGal]

5 minutes ago, MesoscaleBanding said:

Anyone have the 18z Euro?

I'll post it when it's done.

[snowlover2]

6 minutes ago, MesoscaleBanding said:

Anyone have the 18z Euro?

Hasn't run on tropical tidbits yet.

[SOMOSnow]

8 minutes ago, MesoscaleBanding said:

Anyone have the 18z Euro?

Almost done. Will post. 

[Central Illinois]

New 18z EURO has HUGE area of 45-60mph wind gusts across IL/IN/OH for 18+ hrs

[Hiramite]

WPC's Heavy Snow Discussion just issued...

(put the code inside the quote box)

If you don't want to read the whole thing, here's the important part for much of the OV....

Additionally, the potent arctic front will be racing eastward through the period, causing extreme temperature drops of as much as 20-30 degrees in just 6 hours, and allowing rain to change to snow across the MS VLY, TN VLY, OH VLY, and into the Mid-Atlantic and Northeast. While cold air chasing moisture is usually not a favorable setup for accumulating snowfall, the rapidity at which temperatures fall should allow the DGZ to remain saturated, at least for a short time, with anafrontal precip persisting. This could result in a quick burst of heavy snowfall just behind this front, with a flash freeze also likely.

Quote

Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
653 PM EST Tue Dec 20 2022

Valid 00Z Wed Dec 21 2022 - 00Z Sat Dec 24 2022

....Northern Great Plains through the Interior Northeast...
Days 1-3...

...Significant blizzard with extremely cold temperatures and a
flash freeze likely...

An elongated closed mid-level low near Saskatchewan will dig
southward beginning Wednesday night and amplify into a short
wavelength but high amplitude negatively tilting trough, before
closing off across the Upper MS VLY Thursday night. This feature
will continue to amplify into a strong closed low with 500-700mb
heights falling to -4 standard deviations according to the NAEFS
ensemble tables. As this evolution occurs, coupled jet streaks
will develop both upstream and downstream of the primary trough
axis, with the trailing jet streak peaking above 150 kts. The
overlap of the strong mid-level low and coupled jet streaks with
accompanying robust diffluence will drive impressive omega through
a deep layer, resulting in a surface low pressure tracking from
Nebraska, to the Ohio Valley, and occluding strongly into the
eastern Great Lakes/southeast Canada on Friday. Impressive warm
and moist advection ahead of this system will spread significant
moisture northward from the Gulf of Mexico, and although the
system will be progressive into Friday, it is likely to slow as it
occludes D3, with isentropic upglide coalescing into a moderate
TROWAL to enhance snowfall across the Great Lakes.

With exceptionally cold air funneling in from Canada behind the
associated arctic front, SLRs will be quite high, around 20:1 in
many areas, so even as forcing remains transient through the
middle part of the country, a period of heavy snow is likely due
to the rapid accumulation that can occur with such fluffy SLRs.
Additionally, as the low deepens and the pressure gradient
maximizes between the low and the approaching strong surface high,
blizzard conditions will likely develop even where snowfall is
modest, producing widespread notable impacts despite snowfall
totals exceeding 4 inches only east of the Dakotas. For D1, WPC
probabilities for more than 4 inches are above 40% only across the
Coteau des Prairies of SD/MN through central MN, and increase D1.5
and into the Bayfields Peninsula of WI. An axis of heavier snow of
more than 6 inches is likely just NW of Minneapolis and into
northern WI/western U.P. of MI where moisture convergence occurs
along an inverted trough. For D2, the heaviest snowfall shifts
from central MO through both the L.P. and U.P. of MI where WPC
probabilities exceed 20-40%, with more than 6 inches likely in
parts of WI and MI. However, by D3, as the low occludes and slows
down, much heavier snowfall is likely, especially across the U.P.
and western L.P. of MI where wraparound/deformation snowfall will
be persistent, and enhanced by lake effect snowfall. WPC
probabilities for more than 4 inches are high across northern IN
and much of MI, with locally more than 12 inches likely in the
favored lake belts along the northern U.P. and far SW L.P. near
Grand Rapids. This combined with snow and strong winds may result
in blizzard like conditions for parts of Friday, although the most
significant blizzard conditions should be across the
Plains/Midwest due to the strong winds despite lesser snow
amounts. Travel later this week will be extremely difficult across
this part of the country.

Significant snowfall exceeding 4 inches is also possible on D3
downwind of Lake Erie and Ontario as westerly flow develops behind
the front.

Additionally, the potent arctic front will be racing eastward
through the period, causing extreme temperature drops of as much
as 20-30 degrees in just 6 hours, and allowing rain to change to
snow across the MS VLY, TN VLY, OH VLY, and into the Mid-Atlantic
and Northeast. While cold air chasing moisture is usually not a
favorable setup for accumulating snowfall, the rapidity at which
temperatures fall should allow the DGZ to remain saturated, at
least for a short time, with anafrontal precip persisting. This
could result in a quick burst of heavy snowfall just behind this
front, with a flash freeze also likely. Deteriorating travel
conditions are possible during this evolution, for the MS-TN-OH
Valleys on Thursday, and into the Mid-Atlantic and Northeast on
Friday.

 

 

Edited December 21, 2022 by Hiramite

[SOMOSnow]

18z Euro kuchera. Goes to hour 90. 👇

Edited December 21, 2022 by SOMOSnow

[BuckeyeGal]

[BuckeyeGal]

It is juicier, it appears, for the Northern part of Ohio, and some of Indiana and Michigan.

[Wnwniner]

3 minutes ago, BuckeyeGal said:

More of those N/S oriented fingers in Ohio I was referring to. Does that have to do with how much precip is around when the change occurs? If so thY feels like a nowcast situation.

[BoroBuckeye]

Definitely looks juicer.  Low strength and placement looks identical to GFS.

[SOMOSnow]

Its a bit frustrating to be one of the few on the board trending down since last night. Hopefully tonight with full sampling expected will improve here.

By the way, anyone know how much sampling we got with 12z?

[MesoscaleBanding]

1 minute ago, SOMOSnow said:

Its a bit frustrating to be one of the few on the board trending down since last night. Hopefully tonight with full sampling expected will improve here.

By the way, anyone know how much sampling we got with 12z?

Just partial with 12z 

Track should be pretty well set with tonight's 0z into tomorrow morning's 12z suite.

[SOMOSnow]

3 minutes ago, MesoscaleBanding said:

Just partial with 12z 

Track should be pretty well set with tonight's 0z into tomorrow morning's 12z suite.

Thanks! I knew it was partial but was trying to ask how partial, if that makes sense. 

[Hiramite]

FWIW.  (And for those who might not know, the WS Warning Criteria varies geographically.)

 

Edited December 21, 2022 by Hiramite

[MesoscaleBanding]

2 minutes ago, Hiramite said:

FWIW.  (And for those who might not know, the WS Warning Criteria varies geographically.)

 

Due to differences in criteria, I'd think chances might be greater for seeing a blizzard warning than a WSW with this system, no?

[Hiramite]

24 minutes ago, MesoscaleBanding said:

Due to differences in criteria, I'd think chances might be greater for seeing a blizzard warning than a WSW with this system, no?

Good question to which I don't know the answer, maybe a met in here knows. 

I did wonder about what the WS Watches might be upgraded to if the Snowfall criteria wasn't met.   Did some snooping just now, found this condition....

3. Impact Driven: Winter storm is forecast but accumulations will not meet traditional criteria.

6.3.2.3 Impact Criteria
The following is an example of impact criteria: A winter storm is forecast but accumulations will not meet published criteria. However, if it is early in the season or during a critical time of day such as rush hour when the impact will likely be high, then a Winter Storm Warning might be warranted. The forecaster may message winter weather hazards based on locally defined impacts through core partner feedback, and coordinate with surrounding WFOs for a consistent message. Alternatively, WFOs can also opt for means of alternative messaging in lieu of the existing suite of winter warnings for locations at or above criteria when impacts are not expected to warrant alerting due to local climate or elevation and the risk of over-warning.

 

Again, I don't really know, this is just a guess on my part.

Source: NATIONAL WEATHER SERVICE INSTRUCTION 10-513     OCTOBER 12, 2022

Edited December 21, 2022 by Hiramite

[SOMOSnow]

Wouldn't it be absolutely amazing if full sampling throws more qpf at us all and slows this down a little, too and revs the totals up? 🤔♥️

Edited December 21, 2022 by SOMOSnow

[CIWeather]

1 minute ago, Hiramite said:

Good question to which I don't know the answer, maybe a met in here knows. 

I did wonder about what the WS Watches might be upgraded to if the Snowfall criteria wasn't met.   Did some snooping just now, found this condition....

3. Impact Driven: Winter storm is forecast but accumulations will not meet traditional criteria.

6.3.2.3 Impact Criteria
The following is an example of impact criteria: A winter storm is forecast but accumulations will not meet published criteria. However, if it is early in the season or during a critical time of day such as rush hour when the impact will likely be high, then a Winter Storm Warning might be warranted. The forecaster may message winter weather hazards based on locally defined impacts through core partner feedback, and coordinate with surrounding WFOs for a consistent message. Alternatively, WFOs can also opt for means of alternative messaging in lieu of the existing suite of winter warnings for locations at or above criteria when impacts are not expected to warrant alerting due to local climate or elevation and the risk of over-warning.

 

Again, I don't really know, this is just a guess on my part.

I was going to say, I wonder if they may still do a WSWarning just because of the impacts

[beaver56]

7 minutes ago, SOMOSnow said:

Wouldn't it be absolutely amazing if full sampling throws more qpf at us all and slows this down a little, too and revs the totals up? 🤔♥️

One has to believe there is still a curveball or two yet to come.

[MesoscaleBanding]

Just now, beaver56 said:

One has to believe there is still a curveball or two yet to come.

Always is...I've got my eye on the rapid changeover along the Arctic front - could be some nowcast fun & games if the cold air can catch enough of the moisture before it moves through. Without any wrap-around action to hang our hats on anymore, those of us to the east of the primary storm track have all our eggs in this basket.