12/10-12/12 Plains/Midwest/Lakes Weekend Snowstorm

[jaster220]

00z GFS...another look...would be a nice warning snow system for many in the region...from what I can tell, the wave does not split or elongate in the Plains and bundles the energy better this run.

 

Yeah, I thought this looked more worthy of the title "Snowstorm" than "Snow Event"   Actual cold air in place.

 

NAM HR 84:

 

http://maps1.pivotalweather.com/maps/models/nam/2016120706/084/refcmp_ptype.conus.png

 

Go NAM! I love you NAM.   (that's a nice looking precip shield btw) 

[james1976]

DMX not biting on the high qpf.....but still says headlines may be needed.

[Tom]

LOT's early take...

 

 

 

Where things differ is in the strength of the upper flow pattern and
whether a surface low will completely develop over our area as
the GFS/GEM say, vs remaining as an inverted trough axis like the
EC before the surface low develops to our east. This leads to
significant differences in the strength and timing of forcing and
therefore associated QPF, with the GFS double the amounts of the
EC (more in some places), and spread in GEFS ensembles of 0.2 to 1
inch of QPF. The GFS ensemble mean is around 0.55 and the Euro
ensemble mean is around 0.3. Therefore while forecasting amounts
are futile at this juncture, no matter how you paint it,
accumulating snowfall of at least several inches is expected
during this time.

[Tom]

00z EURO with a general 3-4" event for most of us.  I can only paste a local blow up shot of Chicago...

 

 

 

 

 

SREF's for ORD...

 

[St Paul Storm]

MPX's take this morning:

A check of the CIPS analogs using the two windows that cover our

area yielded two analogs that have a similar upper air/H85 pattern.

Although they were both in the bottom five of the analogs, the

precipitation pattern more closely matches what the current

solutions are showing. The top analogs just either didn`t show

much snow or the orientation of the snow was wrong with the

pattern unfolding. The one analog was 12/09/2008 with the second

being 11/29/1988. This would suggest the heaviest snow across the

southern third of MN/northern IA and adjoining areas of west

central WI with amounts in the 4 to 8 inch range. The high end

amounts may end up near the I-90 corridor and a winter storm watch

may be needed if noted trends stabilize.

[Tom]

Yeah, I thought this looked more worthy of the title "Snowstorm" than "Snow Event"   Actual cold air in place.

 

 

Go NAM! I love you NAM.   (that's a nice looking precip shield btw) 

I'm still trying to figure out how to do that!  

[Tony]

I'm liking the earlier onset of the snow as well as the long duration of this event. As of 6z anywhere from 8-14" looks like a good bet from the Dakotas to Illinois. System sure is gaining strenght/wetter with each model run. Have not looked at the Euro run but I guess from what I have read there is no need at this time.

[Niko]

Its looking very impressive for the weekend system. Good thing is that cold air will be in place.

[Niko]

Yeah, I thought this looked more worthy of the title "Snowstorm" than "Snow Event"   Actual cold air in place.

 

 

Go NAM! I love you NAM.   (that's a nice looking precip shield btw) 

Yup, that is a good shield of precipitation knocking into MI.

[gosaints]

NAM is quite a ways north but its take it with a grain of salt timeframe for the nam

[Tony]

Its looking very impressive for the weekend system. Good thing is that cold air will be in place.

And if we do get this weekend storm just imagine how cold it can get for next week...brrrrr.

[Niko]

And if we do get this weekend storm just imagine how cold it can get for next week...brrrrr.

It will be brutal for many on this forum and to top it all off, a real big storm will be eyeing us down in the 4 corners region. So, you can only imagine the snow ratios.

[East Dubzz]

Alright, need the 12z to start coming back south again.

[Tom]

12z GFS still coming in juicy...nice hit N IA/S MN through HR 90..

[Tom]

Nearly identical to the 06z run...weakens a bit as it heads eastward...ground temps should maintain in the 20's from N IL on north so better snow ratios will occur if trends continue...that's a nasty cut-off for IA and C IL....

 

 

 

 

[ToastedRavs]

[GDR]

So is the cmc a bad model or what?? Do we just go by the gfs?

[WBadgersW]

Wish it wouldn't weaken so much as it moves East. Either way this might be the biggest storm I've seen since 2013/2014

[Tom]

12z GFS total precip...prob thinking 12:1 - 14:1 snow ratios...850's near -8C or colder with 528 thickness for the majority of the snow event...

 

http://www.tropicaltidbits.com/analysis/models/gfs/2016120712/gfs_apcpn_ncus_18.png

[Jaycee]

Nice... I think we can officially rule this one out for us out here, given the consistency of it being north. Dang storm. Couldn't be a more perfect track for us either. Just a shame.

[hlcater]

Why on earth is Linn county ALWAYS the cutoff, where airport gets 2" and the north part gets 10"

[jaster220]

Nearly identical to the 06z run...weakens a bit as it heads eastward...ground temps should maintain in the 20's from N IL on north so better snow ratios will occur if trends continue...that's a nasty cut-off for IA and C IL....

 

Most likely cause??

 

The only time I like a cutoff is when it's on a nice pair of women's legs. Not in a storm, not on the road, not at the bar. Cutoffs are brutal with that lone exception!

 

ROFLMAO!   

 

So is the cmc a bad model or what?? Do we just go by the gfs?

 

What. Read somewhere else (JB?) that the CMC Op isn't doing great (new computer in the works btw) but the CMC Ensembles actually verify much better. Tom, can you see/get them??

[jaster220]

So, how many hours until that circled area in eastern SD has their snow? Feel pretty good that if that portion happens as portrayed, the rest plays out as well.

 

 

[gosaints]

So, how many hours until that circled area in eastern SD has their snow? Feel pretty good that if that portion happens as portrayed, the rest plays out as well.

 

20161207 GFS 12z 105hr SNfall.JPG

I agree its really not that far out but the models are all over the place still

[Tom]

So, how many hours until that circled area in eastern SD has their snow? Feel pretty good that if that portion happens as portrayed, the rest plays out as well.

 

20161207 GFS 12z 105hr SNfall.JPG

78-84 HR's...

[Tom]

12z GGEM a bit weaker but generally lining up with the GFS on placement of the snow swath...better love for IA folks and downstate IL...

 

http://maps3.pivotalweather.com/maps/models/ggem/2016120712/102/snku_acc.us_mw.png

[Tony]

I will accept either one. Also, ratios will be a little better farther north so add some to those totals.

[Tony]

2m temps at onset of snow

 

[gosaints]

2m temps at onset of snow

GFS slightly warmer.  Probably why it is a little firther north with a little more juice

[gosaints]

GEFS seem to be trending slightly drier.  But not by much

[gosaints]

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2016120712/gfs-ens_apcpn_us_17.png

[Tom]

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2016120712/gfs-ens_apcpn_us_17.png

 

GEFS suggesting 4-8" in the heaviest band???

[East Dubzz]

12z GGEM a bit weaker but generally lining up with the GFS on placement of the snow swath...better love for IA folks and downstate IL...

 

No idea how PW gets those totals with this amount of QPF:

 

[Tom]

No idea how PW gets those totals with this amount of QPF:

 

http://www.tropicaltidbits.com/analysis/models/gem/2016120712/gem_apcpn_us_16.png

Bullish on snow ratios, but I doubt they are that high anyway...

[St Paul Storm]

So the 12z NAM and GFS are in the more northern camp through hour 84. Now the 12z GGEM is more like the 0z Euro with a bit less precip and a bit south. You knew this wouldn't be easy. Those big 1030mb highs in southern Canada have me a little concerned that this thing can't stay as far north as some models are showing.

[jaster220]

I agree its really not that far out but the models are all over the place still

 

Perhaps due to this? Any truth to the possibility that this a 2-wave event??

 

 

 

NAVGEM is similar to Euro with a 1-2 punch...northern piece moves through on Sunday & then the southern energy rides up on Sun. night/Monday... 

[Niko]

Perhaps due to this? Any truth to the possibility that this a 2-wave event??

Sweet!

[jaster220]

78-84 HR's...

 

12km NAM with a massive snow shield in that time frame 

[ToastedRavs]

12z Euro coming in juicier for us in central Iowa, still not a monster but at least it's more than the two hundredths from 0z. Up to near a third of an inch qpf through midnight Sunday night

[jaster220]

@ Tom

 

I keep getting upload errors. The size it wants to allow keeps getting smaller and smaller. Is there a daily limit or something??