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

[Tom]

I wonder what Tom Skilling is thinking back home…

[jaster220]

5 minutes ago, Tom said:

I wonder what Tom Skilling is thinking back home…

Haha. Where's "back home" for TS? He retired there I presume? Wanted to say that the 12z Euro weak sauce vs (amazing to even be saying this) is more of a Jan '99 vs Jan '78. Prolly top (2) impactful storms for the east half of the Sub at least (or mid Idk, it's grown so large)

[Tom]

3 minutes ago, jaster220 said:

Haha. Where's "back home" for TS? He retired there I presume? Wanted to say that the 12z Euro weak sauce vs (amazing to even be saying this) is more of a Jan '99 vs Jan '78. Prolly top (2) impactful storms for the east half of the Sub at least (or mid Idk, it's grown so large)

I’m still in AZ so I said back home as in  Chicago…. 

[westMJim]

While nothing to do with the upcoming event. The snow has now stopped here. I just took a snow fall measurements and here in MBY I have a total of 10.5" on the ground. There are some breaks in the clouds now and the temperature is now at 29.

[james1976]

34 minutes ago, Tom said:

I’m still in AZ so I said back home as in  Chicago…. 

When you plan on coming back to Chicago?

[Hoosier]

Maybe too early to be getting into these details, but the progged slowdown somewhere around the Lakes, should it occur, will only serve to make things more impactful.  Quite plausible based on latest model solutions that there would be a good 24-36 hours of gusts over 40 mph over a very large area, with a window of higher winds than that.  

[winterfreak]

18z ICON similar to EURO. Not loving these trends. Wraps up too late leaving us just a small window for precip. Always something…

[FV-Mike]

LOT AFD

It is also worth acknowledging the elephant in the room, which is
that there are model solutions suggesting a potentially higher
impact winter weather scenario may unfold somewhere in the region
during the Thursday-Friday timeframe, a peak travel period heading
into the upcoming holiday weekend. We are monitoring this very
closely, though we want to add that there remains a lot of
uncertainty in how things will ultimately unfold given it is still
several days away and urge caution to not lock onto specific
operational model runs as there remains a lot of spread among the
various ensembles. We encourage everyone to stay up to date with
the latest forecasts over the coming days as we get closer and
confidence in how this event will ultimately play out increases.

Where confidence is higher, however, is in the potential for at
least some accumulating snow falling across the area during the
Wednesday night-Friday timeframe, which combined with gusty winds
would result in some travel impacts and bitter cold wind chills
below zero heading into the holiday weekend -- regardless of how
much snow ends up falling and how high the winds end up getting.
If you haven`t already, winter prep for your home and vehicles
should be done early in the week!

[jaster220]

GRR

-Late week storm potential

Guidance continues to show the potential for impactful storm for
the end of next week. A powerful mid to upper level wave digs down
from the Canadian Rockies becoming negative tilted as it enters
the Great Lakes region. This system draws up abundant Gulf
moisture which meets up with the arctic air advecting in from the
Upper Midwest to generate heavy precipitation here in MI. There
is still a lot of uncertainty on how much impacts we will see but
confidence is on the increase that we will see some winter impacts
by this storm. The GFS deterministic has trended west with surface
low track...taking it up through the east side of MI...while the
ECMWF has is coming over the west side of the state. The Canadian
looks a lot like the GFS. These two models would support a heavy
windy snow event through the duration. While the track of the
ECMWF would support a transition to a period of rain...the onset
and backside of that run would still generate winter impacts. The
ECMWF ensemble shows plenty of members with heavy snow.
Still... much can change on the details...but based on the
ensemble trends...confidence on impacts is on the increase
starting Thursday and continuing into Saturday.

[jaster220]

15 minutes ago, Hoosier said:

Maybe too early to be getting into these details, but the progged slowdown somewhere around the Lakes, should it occur, will only serve to make things more impactful.  Quite plausible based on latest model solutions that there would be a good 24-36 hours of gusts over 40 mph over a very large area, with a window of higher winds than that.  

ala '78. KIND had 24 or 30 straight hours of zero vis (airport obs). That's insane at I-70 LAT. 

[Hoosier]

9 minutes ago, jaster220 said:

ala '78. KIND had 24 or 30 straight hours of zero vis (airport obs). That's insane at I-70 LAT. 

With all this talk about 1978 and high winds impacting ratios, I went back and checked some numbers for Chicago.  On Jan 25-26, they had 12.1" on 1.20" of precip, so 10:1 ratio.  I checked a couple other locations and it was pretty similar... like 10:1 to 12:1.  Measuring would've been difficult in that storm and maybe you can find some places that had better ratios, but probably not on the whole.

Based on that and experiences with past windy storms, use the Kuchera snow maps with extreme caution.  Even with it being cold and even if flake production is favorable for dendrites, it's going to be tough to get anything very high ratio.

[Tom]

55 minutes ago, james1976 said:

When you plan on coming back to Chicago?

Monday morning…

[winterfreak]

18z GFS

[metallica470]

1 hour ago, Tom said:

I wonder what Tom Skilling is thinking back home…

He hasn't mentioned too much as of yet other than it's something to keep an eye on especially with the lake enhancement. 

[CentralNebWeather]

4 minutes ago, winterfreak said:

18z GFS

My amounts keep trending up. Not getting too excited yet. Reverse psychology. 

[Hoosier]

Scientifically speaking, the 18z GFS is a disjointed/late organizing pile of crap.

[winterfreak]

GFS still a ways off from a EURO-like solution.

[jaster220]

000
FXUS63 KDTX 172032
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
332 PM EST Sat Dec 17 2022

.DISCUSSION...

The dominant focus for the upcoming week will be the potential for a
significant winter storm by late in the week with a substantial cold
air intrusion in its wake by next weekend.

(Solid acknowledgement for this office with the usual p-type caveats that plague every storm here)

[jaster220]

1 hour ago, Hoosier said:

Scientifically speaking, the 18z GFS is a disjointed/late organizing pile of crap.

But I'm guessing it was more east since it didn't Grinch mby 

[jaster220]

We all get to post some weenie run maps, right??

GFS loop for the ages:

[jaster220]

17/12z GFS

Jan '78

 

[jaster220]

IWX

Medium range models continue to be in excellent agreement in carving
out an impressive pv anomaly into the Central and Eastern US
Thursday into Friday. Rapid cyclogenesis and a potent winter storm
appears likely given a very energetic upper jet and good moisture
return along an associated arctic front. The details
(track/intensity/ptype evolution/etc) are obviously highly uncertain
at this range with expected large spreads in ensemble low pressure
tracks (track overhead with a rain to snow scenario...or east for
mainly snow). With that said, confidence does continue to increase
for a period of accumulating snow and wind toward the end of the
week (Thursday night-Friday), followed by a shot of arctic air and
chances for lake effect snow in time for Christmas Eve and
Christmas. Headline worthy snow, winds and wind chills are
definitely in play. We will continue to closely monitor this system
and patiently await lessening model spread in the coming days.

[Hoosier]

11 minutes ago, jaster220 said:

17/12z GFS

Jan '78

 

Is that bottom image from when they ran the Jan 78 setup through the modern day modeling?  I remember seeing something like that a while back.

[Madtown]

Sure looks like a crazy good Lake effect setup in my neck of the woods as it stands now

[gosaints]

I would caution the goalposts are still giant with this thing....

[jaster220]

37 minutes ago, Hoosier said:

Is that bottom image from when they ran the Jan 78 setup through the modern day modeling?  I remember seeing something like that a while back.

Yes and keep in mind that was after it was already "filling" and drifting ENE. I don't know if I saved the entire loop. Will have to look in my files. Ofc, a major difference between set-ups (not only more than a month earlier on the calendar) is that the '78 event was a merger (surf and aloft) of two distinct systems/branches. An almost perfect merger at 500mb level if you've seen that loop. They say that was responsible for the crazy intensification. Unless this digs way south, then shoots almost due north, I don't see how it could possibly come close to being a 957 mb SLP in NOH. 980-ish would be extremely strong for something at the LAT of S Lakes Erie/Michigan. 

[jaster220]

Just now, gosaints said:

I would caution the goalposts are still giant with this thing....

Track/strength/moisture all up in the air ofc. Cold push seems to be the most common denominator at this range. Without that, we'd not even be entertaining a potential historic outcome. ALL the models could be mis-reading some key ingredient that they suddenly "find" Tuesday, and the air it let out the balloon. For now, Big Dog certainly remains firmly on the table as all the AFD's I read (and CPC) have indicated. Memorable for timing alone should be appreciated too. 

[BMT]

Good writeup from DVN this afternoon.  

Mid to Late Week...

Winter is here, literally. We have the potential to bring in the
first day of winter with quite the show. We have our eyes on a
winter storm set to potentially impact much of the area Wednesday
night and through Thursday. Much uncertainty exists amongst
guidance, with the Euro continuing to be the most aggressive system.
Not only does it have the phasing of systems, but it also develops a
very strong surface low. The GFS is slowly starting to get a grasp,
with the latest deterministic run phasing the system slightly east
of where the Euro brings it. The issue that I have with the GFS is
the fact that the deterministic run is quite different from the GEFS
members and the deterministic run has been inconsistent. Several of
the GEFS members over the last few runs depict quite a different
situation, more similar to the Euro. With that in mind, most
guidance brings in accumulating snow. How much? It is too soon to
say, as this will strongly rely on where/if the systems phase and
the track of the surface low. Not only will these impact the amount
of snow, but these factors will also dictate the potential for
strong winds. As was discussed in the latest forecast package, the
closer the low tracks to us, the potential for blizzard conditions
increases. While deterministic runs are aggressive with the winds
Wednesday through Friday, ensemble probabilities are not favoring
much at the moment. Thus, uncertainty is too high at the moment and
will will continue to monitor.

[jaster220]

CPC Friday pm disco was still sold on EC cyclone. Be curious how Monday pm's will look/read. 

 

[Hoosier]

11 minutes ago, jaster220 said:

Yes and keep in mind that was after it was already "filling" and drifting ENE. I don't know if I saved the entire loop. Will have to look in my files. Ofc, a major difference between set-ups (not only more than a month earlier on the calendar) is that the '78 event was a merger (surf and aloft) of two distinct systems/branches. An almost perfect merger at 500mb level if you've seen that loop. They say that was responsible for the crazy intensification. Unless this digs way south, then shoots almost due north, I don't see how it could possibly come close to being a 957 mb SLP in NOH. 980-ish would be extremely strong for something at the LAT of S Lakes Erie/Michigan. 

I've looked at the 500 mb loop of the '78 storm more than a few times over the years.  

Phasing sort of exists on a spectrum.  This is just stupid good.

[jaster220]

14 minutes ago, Hoosier said:

I've looked at the 500 mb loop of the '78 storm more than a few times over the years.  

Phasing sort of exists on a spectrum.  This is just stupid good.

They say the N Shortwave came straight over from Russian Siberia. It's clearly the stronger of the two prior to the merge. Why that storm may likely never be matched in spite of how similar some of these wild model runs look. 

[james1976]

3 hours ago, winterfreak said:

18z GFS

That's quite the snow shield over the next week.

[jaster220]

41 minutes ago, Hoosier said:

I've looked at the 500 mb loop of the '78 storm more than a few times over the years.  

Phasing sort of exists on a spectrum.  This is just stupid good.

Another thing. That S branch shortwave brought some bigly pwats as it got "sucked" N into the merger. Presuming we even get the wound-up system, moisture may indeed be the key missing ingredient, and make those benefitting from warmer lake temps the big winner zones. I actually expect the 0z suite to come in scaled way back wrt dynamics. I think we've seen the top-shelf runs and things will begin to come down to earth. 

[Hoosier]

29 minutes ago, jaster220 said:

They say the N Shortwave came straight over from Russian Siberia. It's clearly the stronger of the two prior to the merge. Why that storm may likely never be matched in spite of how similar some of these wild model runs look. 

If you just look at the ending of that 500 mb loop from 1978, it looks pretty similar to the current 500 mb progs for next weekend.  It gets there in a different manner though.  No 2 storms are exactly alike.

[jaster220]

5 minutes ago, Hoosier said:

If you just look at the ending of that 500 mb loop from 1978, it looks pretty similar to the current 500 mb progs for next weekend.  It gets there in a different manner though.  No 2 storms are exactly alike.

At the further N latitude it may, just not down where we live. See my other post for another reason '78 had more going for it. This one may have a ceiling closer to GHD-1 or '99 imho

[OKwx2k4]

9 hours ago, Clinton said:

@OKwx2k4you may want to take a peak at the 12z GFS.

See! I get in this dang emotional snowllercoaster too! Haha!

I love it!

Thing with a storm you can guess at with pattern recognition from huge range, it feels like we've been watching this storm a month already. 

[OKwx2k4]

3 hours ago, Hoosier said:

Scientifically speaking, the 18z GFS is a disjointed/late organizing pile of crap.

I appreciate the thorough technical breakdown of the run there friend. Go ahead and tell us how you really feel about it. 

That's too funny. 

Also, "How I have felt about every winter for 7 years." 

[Hoosier]

18 minutes ago, jaster220 said:

At the further N latitude it may, just not down where we live. See my other post for another reason '78 had more going for it. This one may have a ceiling closer to GHD-1 or '99 imho

The 1978 storm was already down into the 960s by the time it entered Ohio.  Just nuts.

In order to get a quicker deepening scenario, we would need the upper low to close off and strengthen more quickly.  Even then, probably couldn't pull off sub 970 mb in southern Ohio haha

[jaster220]

14 minutes ago, Hoosier said:

The 1978 storm was already down into the 960s by the time it entered Ohio.  Just nuts.

In order to get a quicker deepening scenario, we would need the upper low to close off and strengthen more quickly.  Even then, probably couldn't pull off sub 970 mb in southern Ohio haha

Not only that, and that's a serious one. But '78 had existing snowpack all across the S Lakes/OHV from previous storms including that OHV bliz that missed SMI. As soon as snow began, whatever thawing had happened due to warm air ahead of the arctic front, immediately froze up and the new snow had a "jump start" in depth. 5" was the common depth across SMI away from LES belts (where it was more like 12"). Instant 6" depth 1 or 2 hours into the storm. Impacts from the same exact storm starting from zero depth would not be as immediate. Really helped drifts to get out of hand since plow banks made capture troughs for the wind driven snow at onset. Believe I read a report from Jackson that snow set in at 11 pm on the 25th, and by 12 am (1 hour into it) some county roads were already deemed impassable. 

[clintbeed1993]

NWS in Hastings being extremely conservative for this system, almost laughably so considering the major travel timeframe of it. Calling for 1-2 inches and not mentioning anything about higher amounts possible. The write up was a joke mentioning only some light snow with the frontal passage 

[buzzman289]

Really while reading the input everyone puts into  this forum, i am glad i come here everyday. Some times post, but mainly lurk. I learn a tremendous amount of info from All of you, Thank You

[Bellona]

4 minutes ago, buzzman289 said:

Really while reading the input everyone puts into  this forum, i am glad i come here everyday. Some times post, but mainly lurk. I learn a tremendous amount of info from All of you, Thank You

I don't post too much as there are many things I still don't fully grasp. But, I trust what I see even more than the NWS most times.

[Hoosier]

Key wave up around the Arctic Ocean will be in Alaska on Sunday/Monday.  How much this will help the model output, we shall see.

[james1976]

MPX nice write up....says GFS has been trending toward the Euro. Also....the -40 windchill to follow. Full on winter! Eyeballing close to a foot of snow depth currently at the MN home.....and no melting in sight.

The big question mark comes with where the surface low will
eventually track. There appear to be 2 main solutions in ensemble
guidance. One, the trough remains in place over eastern Canada,
resulting in a less amplified ridge over the eastern U.S., more zonal
flow, and a track farther south along the Ohio River (similar to the
12Z GFS). The other, similar to the 12Z ECMWF, lifts the trough out
of eastern Canada with southwest flow across the central U.S. As the
wave rounds the base of the trough, the system takes on a very
negative tilt with a considerable deformation band in the northwest
quadrant. Impressive snow accumulations would be likely. In addition,
as the system deepens, the pressure gradient would increase winds
substantially...resulting in blowing snow, possible blizzard
conditions, and dangerously cold wind chills. This system has the
potential to bring major impacts to a large chunk of the Great Lakes
and Upper Midwest and will need to be watched. At this time, either
scenario is equally likely, but it should be noted the GFS has been
trending closer to the ECMWF in recent runs.

Arctic air will remain in place through the rest of the period. Gusty
winds behind the departing system will keep dangerous wind chills
going with readings possibly colder than 40 below across western MN.

[Hoosier]

While we're waiting on other models, it's kind of cool to loop the 00z ICON and watch the surface low.  At 111 hrs it's around Lake Michigan, and then you see it readjust south and deepen explosively as heights crash southeast and the wave rounds the base of the trough.  Other models have been doing this kind of thing as well... just varying with location/magnitude.

[Money]

Icon 

[Money]

Early look on the GFS through HR 90 and looks to be weaker/East this run 

[Hoosier]

4 minutes ago, Money said:

Icon 

Would point out that some of this in IN/MI (and obviously east) is rain.

[jaster220]

GFS @96 looks slower vs 17/0z

[Money]

Icon at HR 111 had surface low in Chicago while the GFS is like what low?