Dec 11-13 MW/Lakes/OV Snow Event?

[TheWeatherPimp]

Granted based off the GFS, but here's the FIM

[Organizing Low]

i dont know what the Euro is seeing, but it must be seeing something becasue it has cut the storm towards detroit multiple runs now so its unlikely to be a fluke outlier. to me, it seems just like a stronger faster phase, and the lack of any sort of important blocking to the north at first glance.

however of note, is that the thermal profiles in terms of thicknesses and 850s arent all that different for the OV and eastern lakes, and probably portions of the MW back throu chicago/WI (but i havent checked closely enough), compared to the GFS and GEM. its the surface location and occlusion that is quite different it seems.

in addition, what the Euro does with the storm AFTER it reaches then lakes, in terms of a secondary and tilt of the trough as it heads east and speed of such... those aspects have varied substantially in consecutive runs. therefore, the euro is not even sold on itself, as any model shouldnt be at this range.

now whether the euro is right, hard to say its wrong, but more likely a blend of the models is going to be correct as i do not think the phase will be that strong based on how these things tend to play out.... and a suspect occlusion.

im still not even in my own personal window for assessing a storms existence, we still have another 24 hours to go for that, even though all models are signalling.

if it still there then and strongly signalled, i think we are looking at

likely a MAJOR winter storm towards the lower lakes with weak redevelopment (too much energy in the MW for strong) and then the system and shifts east over the lower lakes/northeast with bagginess.

i do think that JB loves to hype, but i could very much see this as being a very intense storm for the MW that is undermodeled.

as for the eastern OV and eastern lakes, i think the lack of blocking, cold air, and occlusive processes will dampen its effects, thought it will still be a major storm with not quite the ferocity it has further west.

[WxMidwest]

From Gil Sebenste at NIU:

Saturday and Sunday...well, the Polar and subtropical jet streams will

phase and produce a big low pressure system as they do. But when and where

this exactly happens is the big unknown, and that directly affects the

track of the low, and its intensity while it affects us. There's little

doubt it will be a major system...not the monster we saw a month ago, but

very intense nonetheless. And it will drop down Arctic air into our area

for the first time early next week. That we know. What we don't know is

the track, how much we'll get, and in what form. The GFS is out to lunch,

because we see it phasing the jet streams at the wrong time and sending

the low down into Tennessee. It's wrong, and climatologically it's way

far south. Then there's the European model, which tracks it right over

DeKalb and I-88 into Chicago on Saturday. That brings us first maybe a

little snow, then freezing rain, then rain, then snow with a flash freeze

on Saturday. Who to believe? Neither, right now. This thing is out in the

Pacific, in a low data area. Methinks the European is somewhat too far

north, and the GFS model is way too far south, while the Canadian

Canadian model taking it through central Illinois might be the best call,

and climatologically, it's close. But again, until Thursday, this thing

is in no-man's land, but be prepared for something ugly, spelled U-G-L-Y

this weekend. Sunday should just be awful, with very cold air moving in

on 40 MPH wind gusts, the GFS and European say it could go as high as 50

MPH in gusts. Blowing and drifting snow...nasty. Sunday, plan on spending

it at home or only with local travel...and if it isn't as nasty, count

your blessings. Look for highs in the lower and maybe middle 30s on

Saturday, and then free-falling on Sunday into the single digits with 40

MPH wind gusts from the north. Lake effect snow in the Chicago area into

northwest Indiana could really be big with this one, if you have travel

plans around the Great Lakes this weekend.

I believe Gil S. on these matters, it makes sense. DT was on the radio show, saying the models won't be viable till Wednesday night at the earliest. Especially with the Pacific Coast sampling yet to come.

[Jim Martin]

Looking like the storm center could pass right over central Ohio this weekend.

[Chicago WX]

Appreciate the thoughts OL. Don't be a stranger.

[B-Rent]

LOL at IND's AFD: LONG TERM /FRIDAY THROUGH TUESDAY/

DID NOT DEVIATE SIGNIFICANTLY FROM HPC GUIDANCE...AS ENORMOUS SPREAD AND MODEL INCONSISTENCY IN THE EXTENDED LEADS TO A LOW CONFIDENCE FORECAST. POTENTIAL EXISTS FOR ACCUMULATING SNOWFALL...OR MOSTLY RAIN POINT OF GENERAL AGREEMENT IS A RETURN TO MUCH COLDER TEMPS EARLY NEXT WEEK. STRONG SURFACE PRESSURE GRADIENT MAY RESULT IN QUITE WINDY CONDITIONS TO GO ALONG WITH THE COLD TEMPS SUNDAY AND MONDAY.

Sometimes I wonder if politicians staff our office.

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[OceanStWx]

Does a track from So. Ill to Detroit work for you. (unscrupulous rhetorical weenie post)

My thoughts this morning were somewhere just north of STL to south of DTW. For now...

Obligatory comment about how the first system will affect baroclinicity and the u/a isn't being sampled yet.

[TheWeatherPimp]

With the winds this thing may have back on the back side of the low, could get awful interesting for whatever locations pick up more then a couple inches of snow.

[TheWeatherPimp]

From IWX:

TEMPS MODERATE INTO THE MID 30S AHEAD OF NEXT STRONG SYSTEM FOR THE

WEEKEND. STILL MANY TIMING/TRACK ISSUES WITH BOTH THE MID/UPPER

FEATURES AND THE SFC/850 LOW BETWEEN THE MODELS. OVERALL.. A

TIGHTER CLUSTER HAS EMERGED WRT SFC LOW WITH THE 12Z ECMWF SHIFTING

SOMEWHAT SOUTH BUT STILL MOVING THE LOW INTO LOWER MICHIGAN WHILE

THE GFS/GEM RETURN TO AN OHIO RIVER/SOUTHERN INDIANA TRACK. BIG

IMPLICATIONS WITH PTYPE/AMOUNTS/BEGIN AND END TIMES BASED ON THIS

WIDESPREAD GUIDANCE AND WHILE WARY OF EWD BIAS THERES BEEN NO

SHIFT IN THE 12Z CYCLE TO MAKE ANY MAJOR CHANGES TO THE GRIDS WITH

SUCH VARIANCE REMAINING BETWEEN SOLNS. AS SUCH WILL STICK WITH AN

ONSET OF MULTIPLE PTYPE WORDING TRANSITIONING TO ALL SNOW WITH THE

SAME TIMING.

BEHIND THIS SYSTEM BRUTALLY COLD AIRMASS STILL PROGGED TO INVADE THE

REGION FOR EARLY NEXT WEEK. POPS IN GOOD SHAPE AS LAKE EFFECT WOULD

RETURN AND WANE BEYOND MONDAY GIVEN PRESENT MODEL OUTLOOK FOR WINDS

DIRECTION...WHICH IS NEEDLESS TO SAY A BIG HEDGE 7 DAYS OUT. MEX

GUIDANCE SHOWING HIGHS IN THE TEENS MONDAY AND IF SOUTHERN SOLUTIONS

PREVAIL FOR WEEKEND SYSTEM AND FRESH SNOW COVER ADDS TO WHAT IS

ALREADY ON THE GROUND...THAT COULD BE OPTIMISTIC.

[Ajdos]

ANYWAYS DTX MIGHT BE BUYING THE EURO I GUESS.. MY ZONE FORECAST

Friday Night: Cloudy, with a low around 24.

Saturday: A chance of rain and snow. Mostly cloudy, with a high near 36.

Saturday Night: Rain, possibly mixed with snow. Cloudy, with a low around 33.

Sunday: A chance of snow. Cloudy, with a high near 33.

Sunday Night: A chance of snow showers. Mostly cloudy and blustery, with a low around 10.

Monday: Partly sunny and blustery, with a high near 17.

[illinois]

I know every time there is a storm that is close but looks north of here I always say to myself perhaps there will be a big shift once this thing gets onshore. But i can't remember a time when the storm get onshore that there was a huge change. Is this a really valid argument?

[OceanStWx]

I know every time there is a storm that is close but looks north of here I always say to myself perhaps there will be a big shift once this thing gets onshore. But i can't remember a time when the storm get onshore that there was a huge change. Is this a really valid argument?

Depends on your definition of huge change. The last clipper was looking like a slam dunk advisory that came into the u/a network and became a concern for warning criteria (which verified in more than one county). Operationally and in public perception that was a pretty big change for our CWA.

[A-L-E-K]

I know every time there is a storm that is close but looks north of here I always say to myself perhaps there will be a big shift once this thing gets onshore. But i can't remember a time when the storm get onshore that there was a huge change. Is this a really valid argument?

No doubt and shifts both ways. I'm sure some of the others can explain the strengths/weaknesses of the upper air sampling net work better.

[JoMo]

I know every time there is a storm that is close but looks north of here I always say to myself perhaps there will be a big shift once this thing gets onshore. But i can't remember a time when the storm get onshore that there was a huge change. Is this a really valid argument?

I think it does matter if there is no consensus between all the models. It will also depend on how and where this storm develops. The Euro wouldn't mature the storm until it reaches Chicago, while the GFS would mature it over Kansas/Missouri.

When the storm is sampled, there will be more of a consensus and the track will be narrowed down.

[Hoosier]

I know every time there is a storm that is close but looks north of here I always say to myself perhaps there will be a big shift once this thing gets onshore. But i can't remember a time when the storm get onshore that there was a huge change. Is this a really valid argument?

It happens, but even though this isn't in the RAOB network, it's not like there is no sampling going on. We know that a significant snowstorm is likely somewhere in the Midwest...will it shift around? Sure. But if you're in Alabama, well, that much shifting is not likely.

[Indystorm]

Heads I get buried with system snow here at Elkhart...tails I get buried by the LES that follows...any takers?

[hawkeye_wx]

Grand Rapids disco explains why they like the Euro

WE CONTINUE TO FEATURE A RATHER AMPLIFIED UPPER LEVEL WAVE PATTERN

ACROSS THE ENTIRE NORTHERN HEMISPHERE...WHICH IS TYPICAL FOR A

MODERATE TO STRONG LA NINA PATTERN. IT IS FOR THAT REASON I LIKE

THE ECMWF`S MORE AMPLIFIED AND PHASED SOLUTION FOR THE WEEKEND

STORM. AT 12Z TUESDAY THERE WAS A CLOSED UPPER LOW OFF THE WEST

COAST WITH A UPSTREAM RIDGE WEST OF THE DATELINE. MEANWHILE THERE AS

A STRONG SYSTEM COMING OFF THE KAMCHATKA PENINSULA HEADING TOWARD

THE BERING SEA. IT IS THAT SYSTEM THAT CLIMBS OVER THE RIDGE OVER

THE WESTERN NORTH PACIFIC OCEAN...WHICH THEN SHEARS OUT THE UPPER

LOW OFF THE WEST COAST THAT RESULTS IN OUR SYSTEM FOR THE WEEKEND.

BY SATURDAY EVENING THERE IS A 140 KNOT JET DIGGING INTO BASE OF THE

TROUGH OVER CENTRAL UNITED STATES. UPSTREAM OF THAT IS A 150 KNOT

JET CLIMBING THE RIDGE JUST OFF THE WEST COAST BY THAN.

IT IS THAT SECOND SPEED MAX THIS IS THE KEY TO ME TO WHAT WILL

HAPPEN. THAT WILL RETROGRADE THE UPPER TROUGH WHICH BY SUNDAY

AFTERNOON SHOULD BE OVER THE WESTERN GREAT LAKES. THAT RETROGRESSION

BY THE UPSTREAM SHORTWAVE WILL JUST WHAT IS NEEDED TO SLOW THE

PROCESS ENOUGH TO ALLOW FOR BETTER PHASING AND MORE NORTHERN TRACK

OF THE SURFACE LOW. ACTUALLY WITH THE OVERALL PATTERN THE ECMWF AND

GFS ARE IN VERY GOOD AGREEMENT. THE ISSUE IS WITH THE DETAILS OF THE

PHASING IN THE SUNDAY TIME FRAME. IT SHOULD BE POINTED OUT THAT THE

ECMWF HAS BETTER CONTINUITY... AS THE 00Z AND 12Z RUNS ARE VERY

SIMILAR FOR THE SUNDAY EVENT... NOT SO FOR THE GFS.

THE BOTTOM LINE TO ALL OF THIS IS THE SURFACE LOW FROM THE SYSTEM

WILL LIKELY TRACK OVER SOUTHERN LOWER MICHIGAN DURING THE DAY TIME

HOURS OF SUNDAY.

[illinois]

No doubt and shifts both ways. I'm sure some of the others can explain the strengths/weaknesses of the upper air sampling net work better.

That is why boards like this are so great. Thanks both of you for your input.

I see your argument about the strength question and how crucial it is to know where your at to figure out where you are going to go. I just know the weenie in me says well this thing isn't sampled yet that's why I'm not getting snow.

[Organizing Low]

Appreciate the thoughts OL. Don't be a stranger.

yeah, u know my location means i am always getting stuck in between the MW/Lakes threats and the EC threats and thats always difficult for me to put my posts in the right spot.

im leaning towards MW on this one.

i hope this works out for many of you.

[OceanStWx]

Grand Rapids disco explains why they like the Euro

GRR covers some points well. The overall upper air pattern is very similar among most of the models. And they are focusing on the major upper air features (jet, h5 highs/lows). These are the features that are driving the storm, and what the models do with these over the next couple of days will tell a large part of the evolution of the system.

[JoMo]

Did anyone post the GGEM ensembles?

[Chicago Storm]

Did anyone post the GGEM ensembles?

No, but now someone did...

[wxman_ind]

Sometimes I wonder if politicians staff our office.

Sent from my Droid using Tapatalk

Yes please vote for me when I run for Emperor. Just kidding of course. I didn't work today, but come on, do you expect us to pretend we're all knowing or be up front and say that due to the uncertainties, it can be either way. I prefer to be up-front myself.

[prinsburg_wx]

Did anyone post the GGEM ensembles?

and for individual members GGEM ENSEMBLES

[snowstormcanuck]

Would have posted the HPC final extended disco but they're not saying much. Pretty much used the EURO ensemble mean as a compromise.

[The_Global_Warmer]

so the euro and it's ensembles are at odds?

[JoMo]

and for individual members GGEM ENSEMBLES

I see, lots of spread until 120 or so. GEM 7 is my fav ensemble.

[snowstormcanuck]

so the euro and it's ensembles are at odds?

EURO ensemble mean is more reminiscent of the CMC, maybe even a little south of that.

[The_Global_Warmer]

EURO ensemble mean is more reminiscent of the CMC, maybe even a little south of that.

Lock it in, hell lock in the GEM.

I can take a ton of rain for a half foot of snow.

at least this is exciting

[Indystorm]

Yes please vote for me when I run for Emperor. Just kidding of course. I didn't work today, but come on, do you expect us to pretend we're all knowing or be up front and say that due to the uncertainties, it can be either way. I prefer to be up-front myself.

I prefer stating the ambiguities as well. Makes for an interesting learning experience.