December Weather In the PNW

[Gradient Keeper]

00z ECMWF - If this run is similar or close to the GFS I'd be a bit encouraged and definitely more optimistic.

 

Day 3

[stuffradio]

The ECMWF has the MJO go all through Phase 8 until the 26th... warm PNW.

 

[Gradient Keeper]

Day 4 - Aleutian ridge looks healthy. Cut-off much further south over southern Baja

http://maps1.pivotalweather.com/maps/models/ecmwf/2017121400/096/500h_anom.na.png

[Brian_in_Leavenworth]

The ECMWF has the MJO go all through Phase 8 until the 26th... warm PNW.

 

ECMF_phase_51m_small.gif

Phase 7 is actually associated with cool PNW temps, as well as cool temps across the Northern Plains. Phase 8 is warm though

[snow_wizard]

The WRF spits out a little bit of snow and 925mb of -5 for the Puget Sound lowlands toward the middle of next week.

[Gradient Keeper]

Day 4 flat ridge over us flattened more

[snow_wizard]

Get rid of political parties, ridges right over the Pacific Northwest, and religion and the world would be a much better place in my opinion.

35 degrees currently.

 

The only time Western ridges are allowed in winter is when there is snow on the ground!

[stuffradio]

Phase 7 is actually associated with cool PNW temps, as well as cool temps across the Northern Plains. Phase 8 is warm though

I was referring to the Phase 8 part.

[snow_wizard]

Day 4 flat ridge over us flattened more

 

That's going somewhere good IMO.

[MossMan]

The only time Western ridges are allowed in winter is when there is snow on the ground!

I agree!

[Front Ranger]

That's going somewhere good IMO.

 

I think so, too. Aleutian ridge a little stronger and further west than GFS.

[Gradient Keeper]

Day 5

[Brian_in_Leavenworth]

I was referring to the Phase 8 part.

 

Ok, understood. Hopefully we can get to phase 1 and 2 soon.

[Gradient Keeper]

Day 6 - Not bad IF the block builds here

http://maps1.pivotalweather.com/maps/models/ecmwf/2017121400/144/500h_anom.na.png

[Gradient Keeper]

[Gradient Keeper]

Block is 9mb stronger than 00z last night

[snow_wizard]

I think so, too. Aleutian ridge a little stronger and further west than GFS.

 

I always look for those well defined stair steps.

[snow_wizard]

Day 6 - Not bad IF the block builds here

 

The persistence of the Kona / near Kona low in the models has been interesting.

[Gradient Keeper]

Day 7 not bad. Block may reorganize around 145-150 W

http://maps1.pivotalweather.com/maps/models/ecmwf/2017121400/168/500h_anom.na.png

[Gradient Keeper]

[Frontal Snowsquall]

Day 7 not bad. Block may reorganize around 145-150 W

http://maps1.pivotalweather.com/maps/models/ecmwf/2017121400/168/500h_anom.na.png

I like where this is headed...

[Gradient Keeper]

Reorganized exactly where I thought!

 

Day 8

http://maps1.pivotalweather.com/maps/models/ecmwf/2017121400/192/500h_anom.na.png

[bainbridgekid]

Not bad

 

[snow_wizard]

MUCH better ECMWF run tonight.  Looks like we're on the upswing again.

[Front Ranger]

MUCH better ECMWF run tonight.  Looks like we're on the upswing again.

 

Yep. Better than the GFS.

[Gradient Keeper]

Day 9 BANG!

http://maps1.pivotalweather.com/maps/models/ecmwf/2017121400/216/500h_anom.na.png

[jcmcgaffey]

Of course after 10 days of clear night skies, high clouds come in just in time for the geminid meteor shower...

[snow_wizard]

The Canadian ensemble looks better tonight also. The control model shows a really good cold wave.

[Gradient Keeper]

[Jesse]

If only we could defy gravity and stay there.

 

Sort of a poor analogy, even though it might look clever from a distance. Unlike the periodic motion of a swing or pendulum, model verification has a set endpoint. Feasibly something can continue to trend well, or poorly, until verification, which isn't nearly as outlandish as a swing continually moving upward, or failing to move downward.

[Frontal Snowsquall]

Day 9 BANG!

http://maps1.pivotalweather.com/maps/models/ecmwf/2017121400/216/500h_anom.na.png

Arctic blast incoming!

[snow_wizard]

Really good Fraser outflow at day 9 on the Euro.

 

This could end up being a really cold month for places that have done well with the fake cold.

[Front Ranger]

I think this is the coldest run yet in the semi-believable range within 10 days.

 

[VancouverIslandSouth]

Really good Fraser outflow at day 9 on the Euro.

 

This could end up being a really cold month for places that have done well with the fake cold.

 

Still looks a bit too close to the coast for "good" Fraser outflow, but it would produce some outflow.

[Phil]

FWIW, this is the perfect pattern to tap into the ECMWF’s cutoff low/SW-drag bias.

[Gradient Keeper]

Two words: Kamchatka Bomb. Massive driver of downstream Amplification and blocking near 150 W. Book it. It sets up around day 6-7. This is about to lock in ladies and gentlemen.

[BLI snowman]

-12C at 850mb at hour 240 for Portland.

 

Going to go out on a limb and guess that that's probably colder than what will actually verify.

[bainbridgekid]

Sort of a poor analogy, even though it might look clever from a distance. Unlike the periodic motion of a swing or pendulum, model verification has a set endpoint. Feasibly something can continue to trend well, or poorly, until verification, which isn't nearly as outlandish as a swing continually moving upward, or failing to move downward.

Definitely.

 

I forget where I saw it, but I read a study recently that there is no evidence of "trends" in the models.

 

Sometimes they get warmer with time, sometimes they get colder, and other times they bounce back and forth. But there isn't a statistically significant relationship between the direction one run goes to the next. (ie. The 18z being warmer than the 12z doesn't make the 00z any more likely to be warmer than the 18z.) The same thing was true for strengths of low pressure systems.

[umadbro]

-12C at 850mb at hour 240 for Portland.

 

Going to go out on a limb and guess that that's probably colder than what will actually verify.

Bold strategy

[Jesse]

FWIW, this is the perfect pattern to tap into the ECMWF’s cutoff low/SW-drag bias.

 

Not buying it huh?