December 2016 Observations and Model Discussion for the Pacific Northwest

[HighlandExperience]

Does anyone view the models on their phone, are the sites mobile friendly?

 

The WRF and most of the stuff on tropical tidbits comes up fine on the phone depending on what you use. 

[snow_wizard]

The ECMWF does hint at a Maritime Continent MJO wave a bit down the road. It may not take long for the Alaska block to re-establish itself if that happens (assuming the block goes away at all).

 

If the 0z ECMWF ensemble verifies Tim and Andrew will probably have lots of snow during week two. It's kind of frustrating that we fight to get moisture when it's cold enough and then we get lots of moisture and it's not quite cold enough. It kind of ticks me off when those two complain.

[Deweydog]

A week or two would be delightful. The 00z GFS the night before last (my favorite run in years), showed something like that.

A week or two is probably a more realistic dream. Cold, persistent suppressed jet setups are pretty rare.

[MossMan]

The WRF and most of the stuff on tropical tidbits comes up fine on the phone depending on what you use.

Thanks, I will give it a try!

[Goducks09]

How come nobody is talking about the PDX snowstorm next Thurs-Fri???  Have we become so cynical that we take everything we see on the models with a grain of salt?

[Deweydog]

Canadian looks more enjoyable. Green lights some kind of event for Thursday and then gives a period of chilly offshore flow after a brief switch to onshore flow.

[Phil]

The ECMWF does hint at a Maritime Continent MJO wave a bit down the road. It may not take long for the Alaska block to re-establish itself if that happens (assuming the block goes away at all).

 

If the 0z ECMWF ensemble verifies Tim and Andrew will probably have lots of snow during week two. It's kind of frustrating that we fight to get moisture when it's cold enough and then we get lots of moisture and it's not quite cold enough. It kind of ticks me off when those two complain.

A maritime continent MJO wave (120E forcing) will act to prevent a GOA block in a +QBO December. You want that forcing around 150E, or "phase 6" on the diagrams you look at.

 

Right now, maritime forcing --> +EPO.

[Jesse]

A week or two is probably a more realistic dream. Cold, persistent suppressed jet setups are pretty rare.

 

They didn't used to be as rare. But I suppose they have always been somewhat rare. It's all relative.

[Deweydog]

How come nobody is talking about the PDX snowstorm next Thurs-Fri??? Have we become so cynical that we take everything we see on the models with a grain of salt?

Looks interesting. It'll be another teeth-gnasher, but has better dynamics.

 

Problem is the models are in flux. One particular run doesn't tell us much.

[Phil]

Hadley Cell expansion since the late 1970s has lead to an overall strengthening and poleward shift in the NPAC jet. There are a number of peer reviewed studies on this..

[Goducks09]

Looks interesting. It'll be another teeth-gnasher, but has better dynamics.

 

Problem is the models are in flux. One particular run doesn't tell us much.

 

True, but I think this feature has shown up somewhat consistently now (I might just be grasping at straws now...) But it is encouraging and within believable range.  We'll see.

[Jesse]

Hadley Cell expansion since the late 1970s has lead to an overall strengthening and poleward shift in the NPAC jet. There are a number of peer reviewed studies on this..

I think this is called anthropogenic global warming in some circles.

[snow_wizard]

No doubt the Canadian looks a lot like last night's GFS. Thursday does have potential.

[snow_wizard]

A maritime continent MJO wave (120E forcing) will act to prevent a GOA block in a +QBO December. You want that forcing around 150E, or "phase 6" on the diagrams you look at.

 

Right now, maritime forcing --> +EPO.

The GFS had been projecting a wave in 8, but now it's changed to 7. Maybe 6 could be doable.

[Phil]

I think this is called anthropogenic global warming in some circles.

No, this is something separate from anthropogenic climate change theory. Even the most extreme attributions can only explain 5-10% of the cell expansion..and in reality it's probably much less.

[MossMan]

No doubt the Canadian looks a lot like last night's GFS. Thursday does have potential.

What about Mondays modified Arctic front?

[Phil]

The GFS had been projecting a wave in 8, but now it's changed to 7. Maybe 6 could be doable.

The GFS has had that WHEM bias all year in the longer range.

[Deweydog]

True, but I think this feature has shown up somewhat consistently now (I might just be grasping at straws now...) But it is encouraging and within believable range. We'll see.

Sure. It's trackable and at worst it'll be a close call. Depending on how trends settle it could end up being a wetter/warmer system or colder/drier to non-existent. Fun times and another something to geek out about.

[MossMan]

The GFS has had that WHEM bias all year in the longer range.

Wasn't that an 80's band?

[TT-SEA]

Seahawks - Rams game in the snow on Thursday night??

[Phil]

For Jesse. Actually an interesting read w/ regards to the weak/broad cell config in the 1880s vs the strong/broad cell config of today.

 

http://www.clim-past.net/8/1169/2012/cp-8-1169-2012.pdf

[MossMan]

Seahawks - Rams game in the snow on Thursday night??

Snow for them two weeks in a row!!

[westcoastexpat]

Yeah...you could be waiting for 4 years for a decent snowfall like people around here have.

 

I can't believe people were down on last nights 0z run. Now everything is more suppressed when the really cold air arrives later in the week. Not that it matters what people want.

 

This area hasn't been amazing either.  There are all the 4"+ snowfalls I have logged for my family's home in metro Vancouver:

 

December 9-10, 2016: 7.5"

December 5, 2016: 4"

February 24, 2014: 9.5"

December 20, 2013: 4"

December 19, 2012: 7"

February 26-27, 2011: 6"

January 12, 2011: 6"

November 25, 2010: 6"

January 3-5, 2009: 4"

December 26, 2008: 10"

December 24, 2008: 12"

December 21, 2008: 10"

December 14, 2008: 6"

 

Maybe other folks in the region can fill in any holes, but I'm pretty sure I have them all covered.

[Deweydog]

WRF is essentially snowless for Thursday.

[TT-SEA]

WRF is essentially snowless for Thursday.

 

 

Ignore it in this situation... operational models show precip much farther north.    I believe this is a bias of the WRF in these set-ups.

[Deweydog]

Ignore it in this situation... operational models show precip much farther north. I believe this is a bias of the WRF in these set-ups.

I agree.

[BLI snowman]

Thursday at least has 1/1/04 potential if that low tracks that far south, just gotta find that impossible medium between a well-developed storm and a weaker area of mid-level WAA. An underachiever looks most likely.

[Brennan]

No, this is something separate from anthropogenic climate change theory. Even the most extreme attributions can only explain 5-10% of the cell expansion..and in reality it's probably much less.

50-75 years ago the current lows hanging off the coast of Vancouver Island might have been hanging off the coast of NW oregon spraying copious amounts of snow on the PNW... instead its 40* rain and all the snow is confined to SW BC... this is how our climate has changed and why we don't get the snow/cold we use to. has shifter north a few hundred miles.

[chopper 918]

Seahawks - Rams game in the snow on Thursday night??

 

Yes please!  I'll be there with my son for his first NFL game.

[bainbridgekid]

The cold air does look slower to arrive now, but the 4km WRF tries to keep precip going into Monday night now for King County. Still appears to be little question the cold blast a little in the week is still on, and thee is still no consensus on how much moisture there migh be with that Arctic front.

 

Pretty interesting to note the ECMWF ensemble is cold at least to some to degree for the next two weeks. It appears we transition to a cold moist pattern. The control model shows the block staying put for the entire period.

Models seem to almost always overestimate how quickly cold air will move in. 

 

It isn't as bad as their bias for pushing cold air out too quickly, but it is definitely significant and seems like something that shouldn't be unfixable.

[bainbridgekid]

Ignore it in this situation... operational models show precip much farther north.    I believe this is a bias of the WRF in these set-ups.

I definitely agree.

 

Been quite a few times (11/22/10 comes to mind recently) when the operational insisted precip would extend much further North of a low than the WRF and ended up being right.

[Arctic Front]

You all just need to chant my name, and I will spread low land snow to all of western washington!

[MossMan]

Models seem to almost always overestimate how quickly cold air will move in.

 

It isn't as bad as their bias for pushing cold air out too quickly, but it is definitely significant and seems like something that shouldn't be unfixable.

So is Monday's modified Arctic front a non event now? Even for my area?

[TT-SEA]

OK...  here is what strong wind and 36 degrees all night does to snow cover.

 

Yesterday morning:

 

 

 

Now:

 

 

 

 

Amazing that it did not even get close to 40 and yet the damage was done.   

[MossMan]

You all just need to chant my name, and I will spread low land snow to all of western washington!

Been doing that every morning for two weeks...with limited effect.

[Prairiedog]

They didn't used to be as rare. But I suppose they have always been somewhat rare. It's all relative.

Snow and cold never came easy for the Willamette Valley, albeit maybe a little more common.  If you look at the ave snowfall charts going back to 1900 Portland never averaged much, what 5" annually maybe?  Now it's closer to 2 I think.  Temps never were much colder either although 1 degree here can mean everything in marginal snowfall events.  People always say,Wow, we used to ALWAYS have cold and snow. Um, no we didn't.  Our childhood memories of a snow event here and there makes it seem like it happened every year.  It didn't.  I think what I remember (having lived here all my life) is that perhaps events lasted a little longer.  It wasn't always just a 12 hr or 24 hr event.  And I'm not even sure my memories of that are accurate.  It has NEVER been easy to get arctic air and snow down here.  It sure can happen but it's not common or easy.  That's MHO anyway. So when people here are so convinced we're gonna see a foot of snow and prolonged cold in the 10 day I chuckle.  It's fun to talk about but its hyperbole.  We all want it and we all hope for it but it's not in our climo DNA.  For those epic events the long range show unless it's inside 2-3 days, I hold my enthusiasm (not easy to do) because 9 times out of 10 I'm left disappointed. 

[Jesse]

OK... here is what strong wind and 36 degrees all night does to snow cover.

 

Yesterday morning:

 

 

 

Now:

 

 

 

 

Amazing that it did not even get close to 40 and yet the damage was done.

You poor thing.

[luminen]

34F and still raining here. Just have a half inch of slush now. 

[TT-SEA]

You poor thing.

 

It is sad for a snow lover to score so big and then have 36-degree wind ruin it.  

[Arctic Front]

Been doing that every morning for two weeks...with limited effect.

Looking back in my database, your location did quite well, even had a surprise snowfall. Your chants have worked