December Weather In the PNW

[MR.SNOWMIZER]

That's excellent. Thanks for putting the animated GIF together.

 

 

It sure looks like it. Oh, for what it's worth 00z CMCE Ensembles were REALLY good.

 

Prediction: 12z runs tomorrow are going to make you need to change your shorts(or pants). All models will come into a good to very good agreement Days 3-7.

Why change them?

[Jesse]

The GFS and Euro are actually pretty similar.

They are definitely both weather models from regions of the world where mostly white people live.

[Brian_in_Leavenworth]

Some areas the low level cold air just didn't seem to mix out. Speaking of which, the cold pool that refused to die is still firmly intact over eastern Washington. Day 14 and counting

 

http://www.spc.noaa.gov/exper/mesoanalysis/s11/925mb/925mb_sf.gif?1513494095492

 

By Tuesday those temps unfortunately warm into the 40's.  Especially since a very wet system is coming, it will be rain for all of us except for the mountains.  It will cool down, only after most of the moisture is gone.  At least that is the current forecast.

[ShawniganLake]

I know its out there, but what are your thoughts about day 10 on the Euro? Maybe undercutting, but maybe another ridge trying to form in the alluetians? Just looked like a very short blast.

Yea, I was wondering if the next week to 10 days is going to be the show. Or if we see a more broad full scale retrogression towards New Years. Phil?

[SilverFallsAndrew]

They are definitely both weather models from regions of the world where mostly white people live.

 

Why does it seem like it is overwhelmingly white men who are obsessed with weather?

[Gradient Keeper]

Yea, I was wondering if the next week to 10 days is going to be the show. Or if we see a more broad full scale retrogression towards New Years. Phil?

I'm wondering this also. Many of the previous Ensemble runs favor prolonged potential, recent EPS has wavered. Tonight's 00z CMCE would suggest the cold pattern may persist well beyond day 10. It seems reasonable too that the westerlies could undercut the block around day 9 to 10.

[James Jones]

00z Euro looks great. I'll take dry cold over no cold any day.

[Frontal Snowsquall]

I know its out there, but what are your thoughts about day 10 on the Euro? Maybe undercutting, but maybe another ridge trying to form in the alluetians? Just looked like a very short blast.

Phil mentioned the Arctic blast would come around January 1 plus or minus 3 days so December 28 to January 4. From there we would have 3 solid weeks to score if I'm not mistaken. What we are seeing around Christmas time is just the appetizer.

[Gradient Keeper]

Phil mentioned the Arctic blast would come around January 1 plus or minus 3 days so December 28 to January 4. From there we would have 3 solid weeks to score if I'm not mistaken. What we are seeing around Christmas time is just the appetizer.

If this is just the appetizer I'm going to definitely need new shorts and tranquilizers. Milk and bread too..

[Brian_in_Leavenworth]

Phil mentioned the Arctic blast would come around January 1 plus or minus 3 days so December 28 to January 4. From there we would have 3 solid weeks to score if I'm not mistaken. What we are seeing around Christmas time is just the appetizer.

That could be.  Wish he would offer his take.  

[ShawniganLake]

Phil mentioned the Arctic blast would come around January 1 plus or minus 3 days so December 28 to January 4. From there we would have 3 solid weeks to score if I'm not mistaken. What we are seeing around Christmas time is just the appetizer.

Assuming Phil is right. Yes.

[Brian_in_Leavenworth]

I'm wondering this also. Many of the previous Ensemble runs favor prolonged potential, recent EPS has wavered. Tonight's 00z CMCE would suggest the cold pattern may persist well beyond day 10. It seems reasonable too that the westerlies could undercut the block around day 9 to 10.

Undercutting could lead to some snow for some people, depending on where any storms go.  Although at face value, apparently the Euro did not show any storms here.

[ShawniganLake]

I'm wondering this also. Many of the previous Ensemble runs favor prolonged potential, recent EPS has wavered. Tonight's 00z CMCE would suggest the cold pattern may persist well beyond day 10. It seems reasonable too that the westerlies could undercut the block around day 9 to 10.

The operationals all look pretty void of westerly break through potential at day10. FWIW

[Brian_in_Leavenworth]

The operationals all look pretty void of westerly break through potential at day10. FWIW

The Euro hints at it.  Block way to the north, a little rain comes in to the Oregon/Ca border.  Nothing definite, but not much to block storms that might want to come in.

[Frontal Snowsquall]

That could be. Wish he would offer his take.

Yeah me too but he's been pretty adamant about it. If he sees something wrong he usually post something.

[Frontal Snowsquall]

Assuming Phil is right. Yes.

I think he will be.

[Brian_in_Leavenworth]

Yeah me too but he's been pretty adamant about it. If he sees something wrong he usually post something.

That's true, he is not shy about delivering bad news or admitting his forecast was wrong.

[Gradient Keeper]

This was a fun night of model riding with you all. Whatever happens, happens. I root for cold and snow. If it's meant to be, then it's meant to be. If not, oh well.

[SilverFallsAndrew]

[SilverFallsAndrew]

This was a fun night of model riding with you all. Whatever happens, happens. I root for cold and snow. If it's meant to be, then it's meant to be. If not, oh well.

 

EPS??????

[AbbyJr]

Lots of positive signs on the models today/tonight. Excited to see what we can score.  ​ 

[Gradient Keeper]

EPS??????

Significantly improved from 12z run. Seems to literally be trending to the nutty CMC/GEM.

[Brian_in_Leavenworth]

Significantly improved from 12z run. Seems to literally be trending to the nutty CMC/GEM.

Looks to be similar so far to the operational.  Anomalies are not as extreme, but you expect that with an ensemble mean.

[Gradient Keeper]

Looks to be similar so far to the operational.  Anomalies are not as extreme, but you expect that with an ensemble mean.

Compare to 12z EPS. Big move towards cold!

[Brian_in_Leavenworth]

Ridge looks healthier at day 10 on EPS, on the operational, it looked like it was being squashed a bit and pushed east by another ridge approaching from the NW, and maybe merging?  On the EPS, there is no 2nd ridge shown, and is still around Alaska.

[Gradient Keeper]

6z NAM is running!

[MikeInEverett]

06z looks pretty much the same as 00z through hour 114.

[MikeInEverett]

Block is a bit more west on this run but nothing to write home about

[MikeInEverett]

Definitely more potential than 00z so far.

[MikeInEverett]

Amplifying in sweet spot

[Gradient Keeper]

6z GFS Day 10

 

WTF the AFLAC duck is attacking Alaska and most of Canada!

http://maps1.pivotalweather.com/maps/models/gfs/2017121706/240/500h_anom.na.png

[Gradient Keeper]

I've NEVER seen a 500mb progression like this before! Seriously what the HELL!

 

What an insane blast this leads to!

 

http://maps1.pivotalweather.com/maps/models/gfs/2017121706/300/500h_anom.na.png

 

 

[TigerWoodsLibido]

I've NEVER seen a 500mb progression like this before! Seriously what the HELL!

 

What an insane blast this leads to!

 

http://maps1.pivotalweather.com/maps/models/gfs/2017121706/300/500h_anom.na.png

 

 

Low coming onshore close to the sweet spot!

[Gradient Keeper]

Day 16 just went full retard. Yep, I'm sure it has a 0.3434839% chance of happening.

 

 

http://maps1.pivotalweather.com/maps/models/gfs/2017121706/384/500h_anom.na.png

 

 

[ShawniganLake]

Low coming onshore close to the sweet spot!

wheres the sweet spot?

[TigerWoodsLibido]

wheres the sweet spot?

Lining the coast for some strong Fraser outflow then dropping down off the Oregon coast and coming inland south of Eugene. Would be close to a regional event going into an airmass that could produce single-digit temps.

[MikeInEverett]

That block would be staying for a while if that were to verify. Holy cow!

[TigerWoodsLibido]

Day 16 just went full retard. Yep, I'm sure it has a 0.3434839% chance of happening.

 

 

http://maps1.pivotalweather.com/maps/models/gfs/2017121706/384/500h_anom.na.png

 

 

Incredible

[MikeInEverett]

The 06z has made staying up the last few nights totally worth it.

[Gradient Keeper]

The 06z has made staying up the last few nights totally worth it.

As you said in the "believable" range days 4-9 6z was improved over 00z. Nothing crazy, but decent backdoor cold for several days leading to a massive cold pool and intense east winds. Day 4-7 were close to being significantly colder if the energy west of the block wasn't so strong.