December Mid/Long Range Discussion

[CAPE]

Seeing a bit more retrogression of the PAC trough towards the Aleutians at the end of the GEFS run. Allows an EPO ridge to build poleward.

[nj2va]

7 minutes ago, stormy said:

Cold air aloft is very marginal at best with the 850 and the 540 line:

Using an ensemble at 330 hours to look at 850mb temps?  Not sure I would look that hard at this stage.  I don't think ensembles would key in on things like that at this point.

[Ji]

39 minutes ago, psuhoffman said:

That's because snow is an anomaly here and at our elevation and latitude it takes way more factors to be in our favor than not.  Kinda like a golf swing...takes multiple things working in unison to get it right...any one little thing can F it all up.   

i dont remember 09-10 that well except for the 3 blizzards but what happened between Christmas and late January. Why didnt we get snow..was it more southern tracks? It wasnt warm from my recollection. Did the STJ dry up?

[WEATHER53]

3 hours ago, brooklynwx99 said:

to be honest, I think that some of the source region stuff is a bit overrated. yes, we would prefer Canada to be cold, but that is usually not the case in El Ninos, even the prolific ones. for example, look at Feb 2010! there was +10-15C air right over SE Canada. made no difference. same with Feb 1987, Canada is torched

An overreaction occurs when around Hudson is +10 to 15 with failure to realize that air mass is still 20 to 25F

[Maestrobjwa]

3 hours ago, brooklynwx99 said:

to be honest, I think that some of the source region stuff is a bit overrated. yes, we would prefer Canada to be cold, but that is usually not the case in El Ninos, even the prolific ones. for example, look at Feb 2010! there was +10-15C air right over SE Canada. made no difference. same with Feb 1987, Canada is torched

Yeah I remember that year the Winter Olympics were in Canada and they were having a snow shortage, lol (remember laughing at that irony while we were buried deep here!) So yeah it was definitely warm! Wait so what was the mechanism that made the cold for those storms?

[brooklynwx99]

2 minutes ago, Maestrobjwa said:

Yeah I remember that year the Winter Olympics were in Canada and they were having a snow shortage, lol (remember laughing at that irony while we were buried deep here!) So yeah it was definitely warm! Wait so what was the mechanism that made the cold for those storms?

+10 air coming out of northern Canada is still cold enough for our intents and purposes

[Scarlet Pimpernel]

15 minutes ago, Ji said:

i dont remember 09-10 that well except for the 3 blizzards but what happened between Christmas and late January. Why didnt we get snow..was it more southern tracks? It wasnt warm from my recollection. Did the STJ dry up?

I recall a clipper type system early in January.  Yeah it wasn't overly warm but I believe a bit above normal overall for that last part of December and then again after the early Jan. clipper.  Then it turned cold late January and we got that "surprise" moderate snow event on the 30th.

[stormy]

18 minutes ago, nj2va said:

Using an ensemble at 330 hours to look at 850mb temps?  Not sure I would look that hard at this stage.  I don't think ensembles would key in on things like that at this point.

I'm not looking that "hard" as the parameters will likely be completely different tomorrow.  But in reality, the model is arguing against itself by painting snow at +3C.

[SnowenOutThere]

Lots of talk about the 27-29th, if we manage to get a good storm track cold air will most likely be a pretty large issue (excluding the transient high idea which is timing we just won't know till later) because good, deep cold isn't really anywhere near us. A pretty good representation of the issue is with the snow depth map of North America, for those wondering, yes ... its worse than 2015. That said, even if it doesn't snow on us that storm would probably help lay down some good snowcover to our north, setting us up for later as the pattern becomes more favorable. 

 

[psuhoffman]

30 minutes ago, Ji said:

i dont remember 09-10 that well except for the 3 blizzards but what happened between Christmas and late January. Why didnt we get snow..was it more southern tracks? It wasnt warm from my recollection. Did the STJ dry up?

There was an arctic shot in late December but we only got a coating of snow with it.  The first 2 weeks of January were very cold but dry.  There was a 1-3" clipper that was it.  IAD had 11 straight days with a high below 40 degrees early in the month.  From the 14th to the 28th was mild as we got a bit too much PAC.  Similar to now.  Then things reverted to the pattern of Dec/Early Jan and it was away we go.  The not so good 2 week Jan pattern is below.  But it was really only 2 weeks that whole winter where the pattern was not so good.  

[TSSN+]

7 minutes ago, SnowenOutThere said:

Lots of talk about the 27-29th, if we manage to get a good storm track cold air will most likely be a pretty large issue (excluding the transient high idea which is timing we just won't know till later) because good, deep cold isn't really anywhere near us. A pretty good representation of the issue is with the snow depth map of North America, for those wondering, yes ... its worse than 2015. That said, even if it doesn't snow on us that storm would probably help lay down some good snowcover to our north, setting us up for later as the pattern becomes more favorable. 

 

Again, we don’t need deep cold. Just need cold enough. 

[brooklynwx99]

the EPS amps the trailing wave well. gets BN heights overhead from the initial wave. this could work

great ridge over C Canada… should promote surface HP in a good spot too

[Chris78]

43 minutes ago, nj2va said:

Using an ensemble at 330 hours to look at 850mb temps?  Not sure I would look that hard at this stage.  I don't think ensembles would key in on things like that at this point.

Exactly. West tracks and other variables will skew the mean.

Big picture is all I'm concerned with from a mean 15 days out

[psuhoffman]

Some of y’all are funny. A few days ago when guidance looked like crap some wanted to push back. Now things look legitimately good and now it’s time to Deb?  

[NorthArlington101]

EURO control has a Christmas Eve Eve miracle

[CAPE]

1 hour ago, stormy said:

I'm not looking that "hard" as the parameters will likely be completely different tomorrow.  But in reality, the model is arguing against itself by painting snow at +3C.

You do realize that is the mean of 30 individual members... no, probably not.

[Ralph Wiggum]

42 minutes ago, NorthArlington101 said:

EURO control has a Christmas Eve Eve miracle

That little discrete wave has been showing up for a few days. Maybe some mood flakes +. 

[Ji]

49 minutes ago, NorthArlington101 said:

EURO control has a Christmas Eve Eve miracle

the euro control has more miracles than Jesus

[Benjamn3]

8 minutes ago, Ralph Wiggum said:

That little discrete wave has been showing up for a few days. Maybe some mood flakes +. 

Hell just give me seasonal temps so I can have a fire in the evening. 

[Blizzard of 93]

The 12z Ensembles continue to have a good look with a workable pattern developing over the last few days of the month.

It’s nice to see a general agreement between the EPS, GEFS & GEPS.

[Blizzard of 93]

 

Cold enough air for snow in late December is getting into place on the EPS & GEPS by the end of the month as well.

•  

[Blizzard of 93]

The improved look on the EPS actually begins to get underway by 12/27.

[WxUSAF]

1 hour ago, psuhoffman said:

Some of y’all are funny. A few days ago when guidance looked like crap some wanted to push back. Now things look legitimately good and now it’s time to Deb?  

Debs in disarray

[WxUSAF]

21 minutes ago, Ji said:

the euro control has more miracles than Jesus

I legit lol’d

[nj2va]

11 minutes ago, Blizzard of 93 said:

 

The improved look on the EPS actually begins to get underway by 12/27.

Wow, so basically this "can kicking its time to punt all of January" is turning out to be like 48 hours of "can kicking."  I hope the debs can handle it.

[osfan24]

4 minutes ago, nj2va said:

Wow, so basically this "can kicking its time to punt all of January" is turning out to be like 48 hours of "can kicking."  I hope the debs can handle it.

Your confidence is something still two weeks away is more than mine, especially after what I've seen. I certainly wouldn't be planning parades and victory laps yet. I would term myself as very cautiously optimistic but skeptical. Hopefully, it''s actually real this time.

[paulythegun]

2 hours ago, stormy said:

I'm not looking that "hard" as the parameters will likely be completely different tomorrow.  But in reality, the model is arguing against itself by painting snow at +3C.

If a model has 15 members out of 50 with a coastal storm with a nice track 300 hours out and 35 members with random stuff (like cutters), then the MEAN temperature is going to be worse than useless. It's going to be misleading! even if the temps were colder, it wouldn't mean much of anything because that could just relate to the timing of the cutter and associated cold front passage. think about 50 separate storms and how they average out on an ensemble map. it's like if someone said, "Well, the ensemble only has a 1000mb mean low pressure reading off the coast 300 hours out, that's not a very strong coastal storm, it's saying it's going to be a weak storm." No it's not! that's the average across a spatial domain!

[WesternFringe]

28 minutes ago, paulythegun said:

If a model has 15 members out of 50 with a coastal storm with a nice track 300 hours out and 35 members with random stuff (like cutters), then the MEAN temperature is going to be worse than useless. It's going to be misleading! even if the temps were colder, it wouldn't mean much of anything because that could just relate to the timing of the cutter and associated cold front passage. think about 50 separate storms and how they average out on an ensemble map. it's like if someone said, "Well, the ensemble only has a 1000mb mean low pressure reading off the coast 300 hours out, that's not a very strong coastal storm, it's saying it's going to be a weak storm." No it's not! that's the average across a spatial domain!

All the debs who doubt the ensembles overall 500 depictions 10-14 days out are often the same folks that think models’ projected temps must be 100% accurate from 10-30 days out.  

[WxUSAF]

5 minutes ago, WesternFringe said:

All the debs who doubt the ensembles overall 500 depictions 10-14 days out are the same folks that think models’ projected temps must be 100% accurate from 10-30 days out.  

Odd how that works

[BristowWx]

41 minutes ago, osfan24 said:

Your confidence is something still two weeks away is more than mine, especially after what I've seen. I certainly wouldn't be planning parades and victory laps yet. I would term myself as very cautiously optimistic but skeptical. Hopefully, it''s actually real this time.

It’s hard to be overly optimistic when the 540 line at 174 is no where in the US.  Even Maine.  It’s the op sure but that doesn’t foster much confidence.