December 15-17 Snow Potential

[Hoosier]

7 minutes ago, Chicago Storm said:

You ask, you shall receive...

Didn't expect to see that in this thread.

[Chicago Storm]

2 hours ago, Stebo said:

Part of the reason why it is weaker is that it is leaving vorticity back in the southwest. No model is doing that and it is a known Euro bias. With a weaker ejection and trailing the vorticity in the southwest, the vort max is easier to shear out instead of coming out as a shortwave.

I wouldn't go that route and discount it yet.

The storm system that has been moving across the country early/mid this week featured the same issue... The GFS was more amped, and was not leaving behind any part of the wave...Which lead to it showing a decent snowstorm across MO/IA/WI/IL/IN/MI on several runs. On the other hand, the Euro latched on to the idea of leaving energy behind, and it took the GFS quite a while to catch up to that idea. In the end, the Euro was right. One cherry picked example, but a recent one.

[Stebo]

1 minute ago, Chicago Storm said:

I wouldn't go that route and discount it yet.

The storm system that has been moving across the country early/mid this week featured some of the same issue... The GFS was more amped, and was not leaving behind any part of the wave...Which lead to it showing a decent snowstorm across MO/IA/WI/IL/IN/MI on several runs. On the other hand, the Euro latched on to the idea of leaving energy behind, and it took the GFS quite a while to catch up. In the end, the Euro was right. One cherry picked example, but a recent one.

The Euro could very well be right, but in your example it wasn't this close in that it was doing it, we are at day 4-4.5 right now.

[Snowstorms]

9 minutes ago, Chicago Storm said:

I wouldn't go that route and discount it yet.

The storm system that has been moving across the country early/mid this week featured some of the same issue... The GFS was more amped, and was not leaving behind any part of the wave...Which lead to it showing a decent snowstorm across MO/IA/WI/IL/IN/MI on several runs. On the other hand, the Euro latched on to the idea of leaving energy behind, and it took the GFS quite a while to catch up. In the end, the Euro was right. One cherry picked example, but a recent one.

Can't disagree with this. 

One thing I want to mention is the UKIE. I been evaluating its performance and its picked up on some key things throughout season. The storm this weekend for example, the UKIE was the first to pick up the storm riding up the Apps whereas the other model suite had it up the coast. Now both the CMC and Euro have a storm going up the Apps whereas the GFS still remains more towards the coast. 

GFS has been atrocious in some cases, but it does have some support from UKIE and CMC right now. 

[Hoosier]

A large amount of 12z EPS members are north of the op Euro.  Like 70-80%

[Stebo]

18 minutes ago, Hoosier said:

A large amount of 12z EPS members are north of the op Euro.  Like 70-80%

All but 5 track a low along the river or north. It is a very substantial shift north/stronger compared to previous runs.

[Hoosier]

17 minutes ago, Stebo said:

All but 5 track a low along the river or north. It is a very substantial shift north/stronger compared to previous runs.

That's even more striking then.  All but 5 is around 90%.  I was going off the general location of the snow band on each ensemble member.  Either way, op is definitely toward the southern end of the range. 

[WestMichigan]

16 minutes ago, Stebo said:

All but 5 track a low along the river or north. It is a very substantial shift north/stronger compared to previous runs.

There area a couple of duds in there but many of them are a decent to very nice hit across the southern 1/3 of Michigan.  Would be nice to see that happen.

[Moosey2323]

DTX AFD

Quote

Uncertainty pertaining to winter storm potential impacting Southeast
Michigan late Monday and early Tuesday:

Entrance region to 170 knot upper level jet axis will undergo change
early next week as entrance region slides east of the Rockies and
both secondary Pacific momentum pushes through subgeostrophic region
of mean trof and subtropical jet merges into the jet axis over
Mexico/Texas. The main forecast question of this package centers on
the potential for mid latitude cyclone development and accumulating
snow over Southeast Michigan Monday/Tuesday. Stonybrook Ensemble
Sensitivity analysis of the 12.00Z GEFS suggests greatest modes of
variation are due to the uncertainty (positional and magnitude) of
the surface anticyclone over the Great Lakes. The ECMWF has been
extremely consistent in being dry with the 12.00Z EPS solutions
overwhelmingly dry with just 2/50 solutions suggesting snow
accumulations. The GEFS and d(prog)/dt of operational GFS is the
opposite with an overwhelming signal for cold deformation snow over
the cwa. The CMC sensitivity analsyis strongly supports a slider
solution of the low pressure system squeezing northeast through the
Tennessee River Valley. Will forgo the GEFS output at this vantage
point given undispersion of members shown in the WWE cluster phase
space. What is of higher than normal predictability is that if
precipitation were to occur, it would fall in the form of snow. The
bottom line is the Day 5 (Monday/Tuesday) timeframe remains a period
of interest for an accumulating snow event, however, the smart money
strongly favors a suppressed southern solution to the mid latitude
cyclone, In other words, a dry solution is preferred for Southeast
Michigan.

 

[Frog Town]

I was just gonna post that DTX Discussion.  I thought it was an in-depth analysis vs. GRR's one or two sentences, LOL.  

[DAFF]

The bottom line is the Day 5 (Monday/Tuesday) timeframe remains a period
of interest for an accumulating snow event, however, the smart money
strongly favors a suppressed southern solution to the mid latitude
cyclone, In other words, a dry solution is preferred for Southeast
Michigan.

 

 Euro train, has left the station... 

 

 

[AWMT30]

Yeah wow DTX is just riding the EURO like no other. Funny to see GRR after this mornings AFD back away so quickly after calling for a potential "Power House" storm this morning. 

[DAFF]

 

[Hoosier]

4 minutes ago, AWMT30 said:

Yeah wow DTX is just riding the EURO like no other. Funny to see GRR after this mornings AFD back away so quickly after calling for a potential "Power House" storm this morning. 

It is a red flag when so many EPS members are farther north, in addition to the other operational models.  It is a bit of a guessing game right now of course but I would be inclined to lean toward the blended solution, which would be north of the op Euro.

[AWMT30]

12 minutes ago, Hoosier said:

It is a red flag when so many EPS members are farther north, in addition to the other operational models.  It is a bit of a guessing game right now of course but I would be inclined to lean toward the blended solution, which would be north of the op Euro.

100% agree with you my dude. 

[Jim Martin]

18z GFS coming in with storm center near Louisville, Kentucky at 96 hours out.

[Stebo]

12 minutes ago, Hoosier said:

It is a red flag when so many EPS members are farther north, in addition to the other operational models.  It is a bit of a guessing game right now of course but I would be inclined to lean toward the blended solution, which would be north of the op Euro.

I disagree with that DTX AFD 100% and furthermore he is basing his forecast on 00z model suite, everything since then has trended north in the EPS and even GEFS to some degree.

[Hoosier]

18z GFS back north.  Ha

[Stebo]

1 minute ago, Jim Martin said:

18z GFS coming in with storm center near Louisville, Kentucky at 96 hours out.

It is north of that, its between Indy and the River.

[Thundersnow12]

There was more ridging earlier on in the run which allowed the wave to amplify more later on. 

Path of the wave alone is a good tell coupled with the good moisture advection should alone be good for at least a swath of advisory level snows somewhere. 

[A-L-E-K]

Would be the best mid range score for the gfs in a long time.

[RCNYILWX]

Would be the best mid range score for the gfs in a long time.

Give the GFS credit for being stubborn on this. I'd be happy to be wrong with my post yesterday trashing the GFS. Definitely a north jump on the 12z EPS for sfc low track vs 06z run, but interestingly the north trend didn't really correspond to beefing up the cold sector QPF. Only about a handful of members approach the more significant QPF/snow amounts this far north like on the GFS. About 20% get the snow swath up into the Chicago metro.

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[Stebo]

4 minutes ago, RCNYILWX said:

Give the GFS credit for being stubborn on this. I'd be happy to be wrong with my post yesterday trashing the GFS. Definitely a north jump on the 12z EPS for sfc low track vs 06z run, but interestingly the north trend didn't really correspond to beefing up the cold sector QPF. Only about a handful of members approach the more significant QPF/snow amounts this far north like on the GFS. About 20% get the snow swath up into the Chicago metro.

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I still think the Euro is grossly underdoing the cold sector precip with this one, no matter what the path ends up.

[Thundersnow12]

10 minutes ago, RCNYILWX said:

Give the GFS credit for being stubborn on this. I'd be happy to be wrong with my post yesterday trashing the GFS. Definitely a north jump on the 12z EPS for sfc low track vs 06z run, but interestingly the north trend didn't really correspond to beefing up the cold sector QPF. Only about a handful of members approach the more significant QPF/snow amounts this far north like on the GFS. About 20% get the snow swath up into the Chicago metro.

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Prepping the ole white flag nicely 

[chuckster2012]

44 minutes ago, Stebo said:

It is north of that, its between Indy and the River.

Over me...sigh...

[Gino27]

7 minutes ago, Stebo said:

I still think the Euro is grossly underdoing the cold sector precip with this one, no matter what the path ends up.

That's why there's a lot of buzz around Ohio right now. If the storm ends up sticking to the southern track and the precip fills in nicely, this could be a good one.

[A-L-E-K]

14 minutes ago, RCNYILWX said:

Give the GFS credit for being stubborn on this. I'd be happy to be wrong with my post yesterday trashing the GFS. Definitely a north jump on the 12z EPS for sfc low track vs 06z run, but interestingly the north trend didn't really correspond to beefing up the cold sector QPF. Only about a handful of members approach the more significant QPF/snow amounts this far north like on the GFS. About 20% get the snow swath up into the Chicago metro.

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consistency points for sure i guess, they're only worth something if it's right tho

[Cary67]

26 minutes ago, RCNYILWX said:

Give the GFS credit for being stubborn on this. I'd be happy to be wrong with my post yesterday trashing the GFS. Definitely a north jump on the 12z EPS for sfc low track vs 06z run, but interestingly the north trend didn't really correspond to beefing up the cold sector QPF. Only about a handful of members approach the more significant QPF/snow amounts this far north like on the GFS. About 20% get the snow swath up into the Chicago metro.

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When it bites the dust it will be a spectacular bust

[LansingWeather]

1 hour ago, Frog Town said:

I was just gonna post that DTX Discussion.  I thought it was an in-depth analysis vs. GRR's one or two sentences, LOL.  

Yeah GRR's AFD's have been complete crud for the last few months. They use to be so detailed and now they are a few sentences. A shame...

[Hoosier]

43 minutes ago, RCNYILWX said:

Give the GFS credit for being stubborn on this. I'd be happy to be wrong with my post yesterday trashing the GFS. Definitely a north jump on the 12z EPS for sfc low track vs 06z run, but interestingly the north trend didn't really correspond to beefing up the cold sector QPF. Only about a handful of members approach the more significant QPF/snow amounts this far north like on the GFS. About 20% get the snow swath up into the Chicago metro.

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To add to that, about 50-60% get the accumulating snow into the I-80 corridor of LOT, especially as you get toward Indiana since the band is generally wsw-ene.