psuhoffman

This H5 equals these temps lol

It's worth noting...the snowfall does NOT align with the H5 look at all...frankly the pattern to the snowfall mean matches a +NAO look more with the greatest +Snowfall anomalies from the upper midwest through Ontario and Quebec. Those are places that usually are warm (for them) and dry in a west based NAO blocking pattern. That said...I will take the H5 look over anything else 100 times out of 100 on a long range prog. Guidance is way more likely to get the large scale longwave pattern correct then any of the synoptic and meso scale details that dictate snowfall. But again...doesn't mean its not worth pointing out the oddity. Let's hope its just an oddity.

Before anyone jumps off a bridge I do NOT take snowfall maps at range seriously....just was posting that for a LOL more then anything else. Of course...come March if we had a west based NAO block all winter and DC doesn't get ANY snow...we can bump this post.

Euro Weekly control manages to have this 30 day H5 look...and not give DC even 1" of snow! LOL I only looked because despite a "weenie" H5 look the snow mean was pretty blah...about 6" in DC and only 10" up here...thats actually below climo snowfall for that 46 day period. So I looked at the control for a clue...I guess if there are runs that manage not to give us ANY freaking snow with that look...lol

The last couple times a SSW obliterated the SPV when the TPV was already weak the ensuing blocking regime lasted quite a while. Even in 2018 when the SSW coupled it set off a -NAO for the next 2 months. Although that was much later so not a great comp. Still I doubt the TPV would recover quickly from this.

All 3 ensembles look the same and pretty good by day 15.

I’m not overly hopeful but wxusaf had a great point the other day. It’s always good when we can see the other side of a bad pattern before it even sets in. And I’ll add it’s always good when we are tracking, even low level threats, during the bad pattern. When I’ve gone back and read threads from good years like 2014 & 2015...there were dead periods and complaining (that should embarrass us looking back) even in those years. I’m not saying this is going to be a good year. But there are signs the base state isn’t totally awful this year.

I’ve noticed the para is a euro clone a lot.

A great look on one side should only require a mediocre in the other.

That's not even cold to boot Ok have it your way

All you do is show 384 hour maps lol That’s not true...sometimes it’s 500 hours

Omg cold anomalies...!!! Lol

They are very unpredictable AND they don’t always couple with the TPV. But when they do it definitely has an effect on the AO. But it’s hard to use something we have such little predictability of usefully for a forecast.

Lot of moving parts. I do think there may be something to this theory. It’s not just Cohen saying it. But it’s also odd that I can remember 4 times recently that a SSW occurred and right before the pattern got suddenly derailed by a huge ridge in the east that originated from the tropical pacific. What just happened this week is eerily similar to what happened in January 2019. What happens after depends though. I’ve read trop coupling is more likely in years with a weak TPV to start so that’s on our side. The last time we had a SSW that coupled in 2018 it initially hurt the progression in Feb (we wasted a strong cold MJO phase wave but then it set up a pretty awesome pattern in March. If we get a similar progression only 5-6 weeks earlier this time...I could live with that! Btw I feel like the end of the 18z gefs needs angel choir music or something. Went all GEPS. Been trending this way for a while but good to see the progression staying locked in time and not getting kicked YET.

I was just ribbing him

There is no way to say conclusively because there are so many variables and no way to isolate them. But there has been a correlation between the pre cursor heat flux to a SSW and a warm eastern US.

It better couple with the trop this time. I’m reading hints the heat flux leading to this SSW might have derailed the pattern progression guidance was seeing a week ago similar to what happened in Jan 2019. I don’t know enough to say but that would be the $&@&

No it lost it on 18z run

Where do I sign?

GEPS was never really on board with the great look in late Dec early Jan but now...

From there is we can get the western trough to split and the vortex to pull back allowing that energy out west to slide under the block that can go somewhere good. If the whole trough keeps digging west....ehh

Yea that’s workable. The pac was ok for most of Dec...and we had a legit threat or two...had that held into mid winter with a -AO we were looking good. Unfortunately the pac looks to have settled into a more Nina base state now.

We need that vortex to back off some. Ideally if it backs off into the WPO it redirects that Nina ridge into the pna domain and western Canada. Absent that it’s even better if it just goes away. That’s not perfect but if...big if..we have a -AO/NAO we have overcome that pac ridge before. But we’ve never overcome both a pac ridge AND AK vortex. That’s just too much for any other factor to fix.

Where do you get the para for non 0z runs?

Funny you say that...teaching is my actual profession...just not weather. I teach Constitutional Law, Economics, and Government. If I ever did go back and finish my Meteorology degree my dream job would be teaching a meteorology course. I wouldn’t mind working on a pacific patterns discussion. What exactly are you looking for? What works wrt snow chances? One issue is I’m not sure what historical analogs still work. I’ve noticed a few times recently a look that in the 50s-90s produced a colder snowy outcome not work wrt temps in recent years. If you narrow the examples to only recent years you get more relevant examples but you get too small a set of snowstorms to draw much significance wrt how likely a pattern is to replicate that result.