February 7th/8th Possible Major Winter Storm???

[Money]

Tons of southern solutions on GEFS:

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2017020300/gfs-ememb_lowlocs_us_20.png

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2017020300/gfs-ememb_lowlocs_us_21.png

[Money]

Several 970's and some 960's:

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2017020300/gfs-ememb_lowlocs_us_22.png

[Money]

6z GFS came in farther SE and hammers the LSE and GB area with 12+

[Niko]

From NOAA:

 

Turning more active next week, as a series of lower amplitude waves
of central pacific origin lead in the eventual ejection of an arctic
system by mid week.

[Tony]

I see the Euro went south. European models vs. GFS but have noticed the GFS has been trending south as well.

[jaster220]

Several 970's and some 960's:

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2017020300/gfs-ememb_lowlocs_us_22.png

I still think south options are on the table. Even if we can't get it as far south as 01.12z Euro, am hoping for at least some backside storm conditions via LES. With wind headlines, should be a very colorful CONUS map. Would love to see all 5 GL's lit up with storm warnings.

[gosaints]

Will be interesting what happens to  the strength of the storm.  So far this season from about this timefame until storm time trends have been to weaken systems.

[jaster220]

Will be interesting what happens to  the strength of the storm.  So far this season from about this timefame until storm time trends have been to weaken systems.

To counter that, ensemble run are notoriously de-amped compared to the Op's, plus the Op's play catch-up wrt strength. So far, the ensembles are strong so I don't think this will go so lame.

[St Paul Storm]

Will be interesting what happens to  the strength of the storm.  So far this season from about this timefame until storm time trends have been to weaken systems.

Without a doubt. IIRC the Christmas Day rain storm/Dakotas special was one of the only ones that didn't come in much weaker than the models depicted. However, even if this storm does come in weaker, it should still produce. It will essentially have the energy from 3 different storms.

[Tom]

HP placement on the 06z GFS is trending better and sliding east a little slower.  It has that "banana" look earlier on...need a little more HP...

 

 

 

http://www.tropicaltidbits.com/analysis/models/gfs/2017020306/gfs_mslpaNorm_us_17.png

 

 

 

 

06z GFS snowfall...3" line creeped south towards the IL/WI border...

 

[Tom]

06z GEFS also trended with more HP...

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2017020306/gfs-ens_mslpaNorm_us_18.png

 

 

 

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2017020306/gfs-ens_mslpaNorm_us_20.png

 

 

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2017020306/gfs-ens_T2m_us_19.png

[Niko]

Some posters on here will get crushed from snow!!

[Tony]

Some posters on here will get crushed from snow!!

Some will get crushed with disappointment.

[Tom]

I've been noticing subtle, but important small changes each run on the GFS.  Firstly, the small piece of energy swinging off of a spinning Aleutian system that tracks towards CA has been slowing every so slightly each run.  

 

 

http://www.tropicaltidbits.com/analysis/models/gfs/2017020306/gfs_z500_vort_namer_8.png

 

The little ball of energy (552 thickness) in the E PAC eventually merges with the closed low off the OR/WA coast.  This closed low has also been trending farther south as well as the northern branch has been pressing every so slightly.

 

http://www.tropicaltidbits.com/analysis/models/gfs/2017020306/gfs_z500_vort_namer_14.png

 

 

The slower that PAC wave comes on shore, the better chance of the northern branch to press south which can shift the storm track south.  That's what I'm going to pay attention to going forward.

[Tom]

12z GFS back north again it looks like...

[Snowshoe]

988 over Chicago at hour 102

[Tom]

988 over Chicago at hour 102

Yup, looks like I will be tracking my barometer instead of measuring how many inches of snow will be falling...

[Snowshoe]

Rain up north to Green Bay and most of lower MI.

[Tom]

Looks like the only chance of seeing any snow around here is when this storm really wraps up and the defo band moves through IA/IL...

[Snowshoe]

Later phase keeping it slightly warmer?

[Tom]

D**n, 982mb near DTW...

[Tom]

Later phase keeping it slightly warmer?

Looks like it, but that can easily change as this PAC wave gets better sampling.  Past experience tracking these type of rapidly intensifying storms is that they can wobble and it would mean a world of difference up by you.

[Tom]

12z GFS...might break that streak Tony!  LOL...

[Tom]

12z Euro looks very similar to the GFS....

[gosaints]

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017020312/ecmwf_T850_us_5.png

[Snoorani]

I still believe this will go south enough still 4 days left. Lets hope!!

[Tom]

I still believe this will go south enough still 4 days left. Lets hope!!

I think it's pretty much locked on an upper Midwest/Lakes storm to get they brunt of the snow.

[bud2380]

Euro shows virtually no backside snow.

[Snoorani]

Is the GFS the only model showing decent backside snow?

[gosaints]

Is the GFS the only model showing decent backside snow?

http://www.tropicaltidbits.com/analysis/models/gem/2017020312/gem_mslp_pcpn_frzn_us_17.png

[St Paul Storm]

Thermals a definite concern at the start on the Euro and GFS...unless you're in the north woods.

[GDR]

Looks like some cold rain

[jaster220]

"Euro went south with the SLP. 996mb over central IN at 120hrs to 979mb over Watertown NY at 144hrs."

 

Was this last night's Euro?? Anyone have that map by chance?? Need one more piece of eye-candy before another 10 mos of warmth.

[jaster220]

I see the Euro went south. European models vs. GFS but have noticed the GFS has been trending south as well.

"Euro went south with the SLP. 996mb over central IN at 120hrs to 979mb over Watertown NY at 144hrs."

 

Any maps of this??

[Tony]

12z GFS...might break that streak Tony!  LOL...

Backside snows generally don't work out so I will say the streak will stay alive.

[St Paul Storm]

12z GEFS shows a pretty tight cluster through NW IL to the southern part of LM. A few low to mid 980s in there too.

[jaster220]

"00z GFS...insisting north camp...."

 

@ Tom - looked back at the clipper thread. GFS's first adjustment south was inside of 100 hrs but it was low on snow amounts. Then it bounced around on SN amnts until maybe 60 hrs out when it had an accurate portrayal. Between 3 & 2 days out it had caught on. With the Fujiwara scenario and all the waves in play and moving parts, I could envision a late game rally for this storm tbh. 6z GEFS showed those HP's getting into the 1030's. Wouldn't take a ton to make this much more interesting at our latitude.

[jaster220]

GRR AFD

 

 

LONG TERM...(Monday through Friday)

Issued at 329 PM EST Fri Feb 3 2017

 

It seems increasingly likely that significant winter impacts will

occur Tuesday into Wednesday. Although forecast certainty with

details remains low at this time, current model trends suggest

freezing rain over our central and northern counties Tuesday and

thunderstorms not out of the question near I-94. What seems more

certain is snow and blowing snow with falling temperature Wednesday.

 

The 12Z models (ECMWF, GFS, GFS ensemble mean, Parallel GFS) and the

00Z ECMWF ensemble have come into better agreement. The storm center

crosses the Chicago area by Tuesday evening then crosses central

Lake Huron. It deepens rapidly with the upper level wave going

negative tilt. The Western Region situational awareness table shows

from 1985 to 2012 from Jan 28th through Feb 18th, pressure this low

occurs once about every 30 years. This does not necessarily mean the

storm itself will be that historic because other factors need to

come into play first.

 

The storm is now near 35N and 155W and will merge with a system

currently stalled off the coast of the state of Washington by

Saturday evening. It then merges out of the Rockies into western

Plains on Monday. By then a 140-150 knot southern stream jet core

digs into the back side of the upper wave as a 160 knot jet departs

the coast of Maine. This creates considerable upper divergence which

allows the upper wave to go negative tilt over Michigan by

Wednesday.

 

Gulf moisture will surge northward into Michigan Tuesday ahead of

the storm and precipitable water values surge to over 0.75 inches by

midday Wednesday. This type of moisture happens once in about 5

years for this particular time of year (again this refers only to

one aspect...the moisture...not the entire storm).

 

The surge of warm moist air Tuesday may lead to a significant

freezing rain event. The CIPs analogs are showing the percent chance

for freezing rain for at least 3 hours is between 40 and 50 percent

between I-94 and I-96 Tuesday.There is also a 60 to 70 percent

chance of at least 4" of snow over our western row of continues

during the lake effect phase the storm. Beyond all of that we would

expect winds of 20 to 30 mph with gusts over 40 mph on Wednesday as

the cold air comes back in. This will mean blowing and drifting snow

as temperatures fall from near freezing at midnight Tuesday night to

the lower 20s by Wednesday afternoon, making roads increasingly

slippery during the day.

 

The track of the storm is crucial. The farther north it tracks on

Tuesday, the less the threat of freezing rain and more of a threat

for thunderstorms affecting far southern Michigan. Lake effect snow

is nearly certain Wednesday - likely over 4 inches in our western

counties so that will mean considerable blowing and drifting.

 

The storm departs Thursday but lake effect will likely continue

through the day ending Thursday evening. Quiet weather is expected

Friday.

 

&&

[Tom]

"00z GFS...insisting north camp...."

 

@ Tom - looked back at the clipper thread. GFS's first adjustment south was inside of 100 hrs but it was low on snow amounts. Then it bounced around on SN amnts until maybe 60 hrs out when it had an accurate portrayal. Between 3 & 2 days out it had caught on. With the Fujiwara scenario and all the waves in play and moving parts, I could envision a late game rally for this storm tbh. 6z GEFS showed those HP's getting into the 1030's. Wouldn't take a ton to make this much more interesting at our latitude.

When you see the 12z EPS, you will lose any hope of this tracking south.  Everything seems to be indicating a Northwoods special.

 

http://www.tropicaltidbits.com/analysis/models/ecmwf-ens/2017020312/ecmwf-ens_T850_mslp_us_5.png

 

 

http://www.tropicaltidbits.com/analysis/models/ecmwf-ens/2017020312/ecmwf-ens_T850_mslp_us_6.png

[Tom]

18z GFS bombs out from a 996mb storm in the Plains down to a 972 mb beast just north of DTX...