brooklynwx99

6 minutes ago, 40/70 Benchmark said:

If all else is equal, but it allows for other factors to overwhelm...just as weaker ENSO does. That shouldn't be prohibitive to an intensifying PV and the development of a PT.

true. I think that Pacific trough is transient as the momentum from the poleward jet extension pushes into AK. then, as the MJO continues progressing, it wouldn't be surprising to see another equatorward extension... that period will become clearer over the next week or so

I think we warm up for a week from like the 10-17th... what happens afterwards is more dubious

2 minutes ago, 40/70 Benchmark said:

BC version has it entering the COD on Xmas eve.

if looking at RMM, the left of the COD is usually a cold signal as well

Just now, Terpeast said:

It looks like this is our first window (I'm on the very very southern edge of it so not expecting much). After this first window, the PNA looks to go pretty deeply negative then rise back to neutral-ish by mid-month. Then we should get another window sometime after that.

yeah, the poleward extension should make things rougher for a week or so, then it should become more favorable again after the 15th as the MJO orbits

even then, the TPV being nearby and a cold source region won't make it impossible to get lucky

this is a pretty obvious colder shift. SE ridge is squashed, potentially opening up a risk for accumulating snow for the Northeast mid-week. can thank the more robust -EPO for that

the trend towards more of a wave break in the Pacific might make the first week of the month interesting... more of a -EPO, which displaces more cold air south. combine that with some lingering vorticity in the SW, and overrunning opportunities may present themselves

5 minutes ago, Stormchaserchuck1 said:

I mean if that MJO forecast verifies, it will be a weird Pacific H5 for what the MJO is. Something to watch to see if that happens: MJO amped in 7-8 and a -PNA/+AO pattern

I would argue that the models are underdoing the Pacific jet and + heights near the WC and AK given that kind of tropical forcing

unless the MJO can never get into 8, which I'm sure I'll be told

16 minutes ago, LakePaste25 said:

For december, one would definitely want to be north of I-80. Even here, probably still dealing with rain from time to time. 

 

the TPV elongating like that into SE Canada should present opportunities for overrunning

the lack of a prolonged SPV disruption lessens the risk of blocking this month... maybe late, but who knows this far out

overall, looks pretty meh for the Northeast into mid-late month. the -WPO and TPV in Canada should continue to present snowfall risks, especially into New England, but large storms look unlikely as long as the NAO remains positive and the PNA negative

should see the PNA rise later on in the month as the MJO continues to progress 

6 minutes ago, 40/70 Benchmark said:

Another interesting tidbit about the modern climate that @Stormchaserchuck1has pointed out is the tendency for -NAO intervals to coincide with -PNA.....which is important considering there should be some -NAO episodes early on. I think there was also a graphic he posted concerning the negative correlation for the following December after a strongly +PNA (last year)....not to mention the GLAAM being significantly more negative than last year. This dove tailed nicely into my expectation for a rapid recovery of the PV and lead into a January reflection event triggering a mid season +TNH pattern.

you usually get the wave breaking needed for -NAO when you get a huge cutter... you usually need -PNA to accomplish this

24 minutes ago, bluewave said:

 

This is the actual 500mb pattern last winter on the 11 days which .20 or more of precipitation fell from Philly to Boston. Very fast extended Pacific Jet along with a Southeast ridge linking up with the Greenland block with a warm storm track through the Great Lakes.

So the NYC average temperature last winter during the days with the heavier precipitation was 41° which was too warm to reach anywhere near average seasonal snowfall. 

Long range models consistently missed this pattern beyond 1 week out. Has nothing to due with luck or Monday morning quarterbacking. The storm track is a function of the pattern. 

I still think it’s possible to change things up a bit. But I am not going to make that forecast based on a week 2 or 3 model forecast. It has to show up in the short term in order to be believable.

11 day 500 mb composite DJF 24-25 when .20 of precipitation fell from Philly to Boston

 

 

honest question, is it possible for models in the 1-2 week range to show a pattern that you will actually get excited about? 

sure, we can play Monday morning QB and say "nooooo those patterns were actually bad because they didn't produce snow!" but that's disingenuous 

not to harp on last year, but models actually did a good job showing the amount of high latitude blocking that developed. to say that a good pattern never developed is just incorrect

11 minutes ago, SnoSki14 said:

You always post the same day 15+ ensembles that show a supposedly amazing pattern that never comes to fruition 

explain to me how the pattern from last year never developed. i want receipts

1 minute ago, bluewave said:

The one constant every December since 2011 from Philly to NYC Metro has been at least one 55°+ warm up even when the long range models were cold between December 17th to 25th.

you are just full of surprises

11 minutes ago, SnoSki14 said:

It's just pure hopium at this point. I don't see anything to be positive about. SE ridge looks pretty dominant and cold dumps west with troughing 

So cold/dry to warm/wet and vice versa will be the theme. Same storm tracks we've been seeing for years now

can you post some ensembles to back up your point? or just anything, really

this is a pretty obvious P8 signal. there is very little, if any forcing showing up on the EPS over the Maritime Continent

1 hour ago, CoastalWx said:

Get it to 50mb before we whack it to wind reversals over the moon.

the PV closer to us has been perturbed already. seems like this should couple pretty well

26 minutes ago, snowman19 said:

Huh. So I guess they’re actually not showing “extreme cold” like I just read on twitter. Man oh man, you have to be really careful who you follow there 

honest question, why are you even on twitter? I avoid twitter like the plague

there are enough knowledgeable people here

the weeklies should not run every day. so stupid

can pretty easily see the N ATL trough feeding back on the Scandi ridge, which then increases heights in the NAO region... this elongates and presses the TPV south

3 minutes ago, GaWx said:

12Z ensemble means at H5 just after the cold shot at the end of Nov:

GEFS:

 

EPS: more amplified including much stronger SE ridge than GEFS:

 

We’ll see which verifies more closely. Lately, cold has had the edge.

the EPS is just a day or two slower. it gets to the same point with a -NAO developing thanks to Scandi ridging (which is typical of SSW events)

really liking the progression on all the ensembles as we head into the first week of Dec

initial equatorward jet extension -> T-day trough establishes cold along with building -EPO/-WPO

trough moves into the N ATL and increases Scandi ridging -> second trough dumps cold into the West and Canada

second jet extension pushes cold east -> N ATL trough strengthens and starts pushing Scandi ridging into the NAO region

really liking the progression on all the ensembles as we head into the first week of Dec

initial equatorward jet extension -> T-day trough establishes cold along with building -EPO/-WPO

trough moves into the N ATL and increases Scandi ridging -> second trough dumps cold into the West and Canada

second jet extension pushes cold east -> N ATL trough strengthens and starts pushing Scandi ridging into the NAO region

really liking the progression on all the ensembles as we head into the first week of Dec

initial equatorward jet extension -> T-day trough establishes cold along with building -EPO/-WPO

trough moves into the N ATL and increases Scandi ridging -> second trough dumps cold into the West and Canada

second jet extension pushes cold east -> N ATL trough strengthens and starts pushing Scandi ridging into the NAO region

like this is just a fail. the stronger Pacific jet actually helps in Ninas most of the time, not hurts