Pre-Christmas Storm Plains/MW/GL 12/21-12/22

[jaster220]

Nice deep-dive from DTX (am)

A significant model trend amongst virtually all of the global
deterministic solutions (ECMWF/GFS/Canadian) has been for a delayed
low deepening and subsequent eastern shift to the low pressure track
(STL-Fort Wayne-Southeast Michigan). This model trend, which began
with the 19.12Z suite, has only firmed up in the 20.00Z guidance.
The cause for the delayed low deepening is because of a double PV
anomaly structure that is resolved in the broad southern Canadian
trough, and a slower progression in drawing the western PV anomaly
southeastward into the Ohio River Valley. Touched on this in my
discussion from two nights ago that it was probably going to be
difficult to get that entire western potential vorticity trough to
fold down that quickly while being phased to the left exit region
dynamics from the start. Not surprisingly then, that as we moved
forward the models began resolving the mass fields differently which
has resulted in less viscous behavior from a fluid dynamics
perspective. So now as it stands, virtually all of the operational
runs are showing this double PV anomaly structure and have really
converged towards the ECMWF solution from 24 hours ago. This
continues to point in a qualitative sense that confidence remains
higher than normal for a Day 3 and Day 4 system.

Very interesting to look at the Cluster Analysis output from the
19.12Z GEFS and see the variability of both EOF1 and EOF2 is down to
some minor height differences under the upper level jet axis over
the western United States. All of the 500mb height variance that was
present in earlier ensemble output over the Great Lakes to Hudson
Bay has vanished. Thus, this technique provides quantitative support
that timing of the jet/trough has been worked out and the GEFS
solution space has taken a big jump towards what has been the ultra
consistent ECMWF consensus. Cluster phase space shows a very good
agreement amongst the CMCE-EPS-CMCE at Day 4. All of this looks good
on the predictability front and with shockingly no null cases over
the past three days, confidence is very high for a massive winter
storm impacting the region.

[jaster220]

Hoping..

It really is a testament to the depth of the low pressure circulation
and the strength of the large scale forcing. This lagging of the PV
maximum in the model data appears to have some influence on the dramatic
wobbles or zigzagging of the surface low track. Given the
trajectories of the upper level forcing, would not be shocked to see
an eastward shift of the surface low track in future model runs. An
eastward shift in the track could provide just enough cooler air and
better midlevel deformation that would yield a quicker changeover to
snow and higher snow amounts.

[Hoosier]

27 minutes ago, indianajohn said:

Pretty much…

May sound a little weenieish and not my intention, but looking at the tracks of the surface/mid level lows, I just kind of have a hard time believing we don't get a good snow out of this here and even back to Chicago.  The progged tracks of those are pretty darn good for us.  The later development may be playing a role (likely is) and obviously there is a tremendous cold/dry push behind the front.  But I don't know... something seems a tad off in the model precip depictions.  I could very well be wrong, but it's giving me some hope at least for now lol.

The 1978 storm dropped a foot in Chicago with a trajectory less favorable than this storm (basically eastern TN north to Cleveland).  That one did start its explosive intensification at a much lower latitude though.

[jaster220]

Both GRR and DTX taking their sweet time issuing pm AFD's

[FV-Mike]

LOT had an update at 11am. at that time noted they were leaning towards warnings being issued

For the Winter Storm Watch, made changes to add some temporal
detail to the start times across the area per most recent trends
in the model guidance. A more progressive trend overall with the
system has now moved up the start of likely dangerous travel
conditions into the daytime on Thursday.

This is tied to a faster progression of a powerful Arctic front,
combined with falling snow, and crashing temperatures. To set
things up for the (likely) warning issuance phase, segmented out
the Winter Storm Watch based on the general consensus of the
timing of the Arctic front passage.

 

[tStacsh]

6 minutes ago, jaster220 said:

Both GRR and DTX taking their sweet time issuing pm AFD's

Lots to digest.  Coordination.  Two phases to this storm.  Normal snow/mix to start, then Friday when the hammer falls.  System will bring different conditions everywhere at the start.  Track isn't really set yet either.  

[Madtown]

Nam a step in the right direction!

[bud2380]

18z NAM

 

[jaster220]

7 minutes ago, tStacsh said:

Lots to digest.  Coordination.  Two phases to this storm.  Normal snow/mix to start, then Friday when the hammer falls.  System will bring different conditions everywhere at the start.  Track isn't really set yet either.  

Oh, no doubt. Busiest these offices have been and at the busiest time of year for most on top of that.

[jaster220]

5 minutes ago, Madtown said:

Nam a step in the right direction!

I think this all comes back to earlier moisture when sampling is digested as DTX wrote. h5 issues to sort through before synoptic/surface comes into better focus. Just a day away from renewed enthusiasm for this system. That cold lurking means business. Fuse in the powder keg just waiting to be lit

[tStacsh]

2 minutes ago, jaster220 said:

Oh, no doubt. Busiest these offices have been and at the busiest time of year for most on top of that.

Worst case scenario for me.  Not a fan of this.  Exciting and memorable, but eek.  

 

WHAT...Blizzard conditions possible. Total snow accumulations of 8 to 17 inches possible through Friday. Winds could gust as high as 55 mph and will cause significant blowing and drifting snow. Additional heavy snow and high winds are expected into Saturday with storm total snowfall possibly reaching 2 feet along and west of US 131 from Kalamazoo northward to Grand Rapids and up into Big Rapids.

[Hoosier]

8 minutes ago, Madtown said:

Nam a step in the right direction!

Just looking quickly, it does deepen the surface low faster.

[Bellona]

Quad cities going with warning as well

[Bellona]

Warning issues by dvn still says 55mph winds. I wonder if they will be replaced with blizzard warnings at some point?

[Madtown]

NAM gonna lead the way. Let's get this party started everyone!

[jaster220]

If we just had the Euro and no other models, there would be so many fewer wx weenie suicides!!

Read KBUF as to why:

[bud2380]

DVN says 4-7".  

 

...WINTER STORM WARNING IN EFFECT FROM 6 PM WEDNESDAY TO 6 AM CST
SATURDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 4 to 7
  inches. Winds could gust as high as 55 mph. Blizzard conditions
  will also be possible, with extreme cold wind chills as well.
  Wind chills as low as 30 to 40 below will be possible, especially
  starting midday Thursday.

[Ottawa CO, MI]

14 minutes ago, tStacsh said:

Worst case scenario for me.  Not a fan of this.  Exciting and memorable, but eek.  

 

WHAT...Blizzard conditions possible. Total snow accumulations of 8 to 17 inches possible through Friday. Winds could gust as high as 55 mph and will cause significant blowing and drifting snow. Additional heavy snow and high winds are expected into Saturday with storm total snowfall possibly reaching 2 feet along and west of US 131 from Kalamazoo northward to Grand Rapids and up into Big Rapids.

I may get 12-18 inches as I am in Ottawa Co. west of Grand Rapids.....west winds could be brutal creating whiteouts...

[jaster220]

14 minutes ago, tStacsh said:

Worst case scenario for me.  Not a fan of this.  Exciting and memorable, but eek.  

 

WHAT...Blizzard conditions possible. Total snow accumulations of 8 to 17 inches possible through Friday. Winds could gust as high as 55 mph and will cause significant blowing and drifting snow. Additional heavy snow and high winds are expected into Saturday with storm total snowfall possibly reaching 2 feet along and west of US 131 from Kalamazoo northward to Grand Rapids and up into Big Rapids.

Dude! Congrats. Once or twice in a life-time deal on the table. ALL will remember a severe storm right at Christmas. Will be told by generations, for generations following.

[indianajohn]

37 minutes ago, Hoosier said:

May sound a little weenieish and not my intention, but looking at the tracks of the surface/mid level lows, I just kind of have a hard time believing we don't get a good snow out of this here and even back to Chicago.  The progged tracks of those are pretty darn good for us.  The later development may be playing a role (likely is) and obviously there is a tremendous cold/dry push behind the front.  But I don't know... something seems a tad off in the model precip depictions.  I could very well be wrong, but it's giving me some hope at least for now lol.

The 1978 storm dropped a foot in Chicago with a trajectory less favorable than this storm (basically eastern TN north to Cleveland).  That one did start its explosive intensification at a much lower latitude though.

I’m with you… my spidey senses are going off as well something not right 

[jaster220]

STORM WATCH is such a lame a$$ color. Looks like stupid hazardous wx outlook

 

[Bellona]

Arx warning 5-8, 45mph winds

[Grizzcoat]

RDPS- sticking to it's guns (or sling shot) :O)

[Grizzcoat]

[Grizzcoat]

DMX going with WSWarn- with likely upgrade to Blizzard Warning it sounds like at least-

Confidence:  Medium to High

The worst conditions will be Thursday into Thursday night, but
lingering higher impact conditions will continue Friday with wind
and blowing snow expected. Despite the snow diminishing Thursday,
winds will continue to be strong as gusts approach 40 to 45 mph or
higher.  Lingering flurries and blowing snow will continue into
Friday. We will carry our winter storm warning for the duration of
the period for now, and the evening/midnight shift will look again
more closely at areas or all of central Iowa, that need to be
upgraded to a blizzard warning with the likelihood of whiteout
conditions at times. The nature of the snow will easily allow for
significant blowing and drifting, making for very difficult to
possibly impossible travel at times. Wind chills are anticipated
to drop to 30 to 35 below Thursday and approach 35 to 40 below
Thursday night into early Friday morning.

 

 

[jaster220]

Mappage. Big Storm

 

[jaster220]

RS

Both NAM and GFS look a bit off in their handling of the short wave rounding the base of the trof, they seem to be trying to develop the eventual low out of the leading wave and trof in place ahead of the energy and they suppress the short wave as a sort of last piece of energy for the southeast U.S. cold front. I think earlier model runs may have had a better depiction with the energy rounding the base of the trof deepening over MO and IL rather than this concept of the low forming in IN and moving to MI. Either way all of the expectations for MI, sw ON, wNY snow belts would verify but there may be a better (worse for public) outcome for WI and IL, maybe even IA and MO. Later model runs (perhaps starting with 12z Euro) may start to drift back to the earlier more intense solutions. I can't see how the overperforming start here would translate into a weaker short wave rounding the base after DEN gets a brief blizzard tonight and Wed a.m., would expect a snowstorm to develop in OK and s KS as the low drops into Texas. I think it will stay more of a dominant feature rather than getting absorbed into some developing low way out ahead of the main energy.

[Madtown]

2 minutes ago, jaster220 said:

Mappage. Big Storm

 

lol come on now

[winterfreak]

8 minutes ago, jaster220 said:

Mappage. Big Storm

 

Lmao. Is this real?

[tStacsh]

Probably more realistic.  Still a massive storm

[Bumblin Bman09]

12 minutes ago, jaster220 said:

Mappage. Big Storm

 

Seems a tad bit off.  Especially around chicago and Wisconsin lol 

[indianajohn]

2 minutes ago, winterfreak said:

Lmao. Is this real?

If it’s any consolation weather channel still has the “bomb cycle” developing with upwards of 12” for Chicago and surrounding areas… 

[winterfreak]

9 minutes ago, tStacsh said:

Probably more realistic.  Still a massive storm

That’s much better lol.

[Madtown]

Maybe we got something  here folks

[tStacsh]

One thing to remember.  The lakes are much warmer right now, than when these storms typically occur.  Not sure how much the models are taking that into account in the snow belts.  That amount of wind and cold air and moisture, really makes me wonder how much snow we get.   I was forecasted for 4-8" last week and ended up with 15.  No model had more than 6"   Models still really struggle with snowfall amounts to this day.  Makes more sense to go with your gut and good old fashioned common sense meteorology.   

 

[Madtown]

Stopped the bleeding.

[bud2380]

GFs upped totals in Iowa. 

[Hoosier]

4 minutes ago, Madtown said:

Stopped the bleeding.

Yes.  Good way of summarizing the 18z cycle.

[winterfreak]

18z GFS looks a bit better:

[tbone8]

URGENT - WINTER WEATHER MESSAGE
National Weather Service Northern Indiana
1152 AM EST Tue Dec 20 2022

...WINTER STORM WATCH REMAINS IN EFFECT FROM THURSDAY EVENING
THROUGH SATURDAY MORNING...

* WHAT...Blizzard conditions possible. A wintry mix Thursday
  transits to snow Thursday night. Snow will be moderate to heavy
  at times late Thursday night through Friday. The snow will
  transition to lake effect snow through Saturday. Storm total
  snow amounts will be quite varied, exceeding 8 inches near Lake
  Michigan to a few inches in northwest Ohio. West winds could
  gust as high as 55 mph, and will cause significant blowing and
  drifting snow.

* WHERE...Portions of northern Indiana, southwest Michigan and
  northwest Ohio.