December 2020 Weather Observations for the PNW

[wxmet]

There’s always next winter.

[SilverFallsAndrew]

Phil is like the pied piper of the weather forum. 

[Winterdog]

1 minute ago, SilverFallsAndrew said:

Phil is like the pied piper of the weather forum. 

We are weather rats?

[Phil]

1 minute ago, SilverFallsAndrew said:

Phil is like the pied piper of the weather forum. 

[Gradient Keeper]

Day 5

[bainbridgekid]

Meanwhile Texas and Mexico get a foot of snow in the next 24 hours . . .

 

[MossMan]

8 minutes ago, Phil said:

Not sure if anyone linked this but for those seeking Dr. Ventrice’s video here it is.

For those seeking instant gratification, start watching at ~ 34 minutes in. I really do like his analysis here including the EOFs to differentiate wave structures and their long term evolution.

FWIW his projection for PNW ~ 40mins in fits very well w/ the timeline we’ve all discussed.

 

 

Watched the entire video a bit ago...Fantastic stuff! 

[SilverFallsAndrew]

8 minutes ago, Acer said:

We are weather rats?

Or the children. 

[Gradient Keeper]

Day 6

[MossMan]

Well we could all head to Leavenworth to get our snow fix...5yrs ago today we did just that! 

[Phil]

Man Andrew is in a very dark place today.

I’m surprised considering the next 10 days are essentially his favorite weather pattern.

[Gradient Keeper]

00z GEFS Day 10-16 GIF

500mb Height Anomaly, 200mb Jet. Positive anomalies popping up across the Pacific with the NPAC, WPAC jet retracting and dying. It looks like the models are starting to pick up on the major NPAC pattern change. Here we go!!!!

 

 

[Deweydog]

Things are going to get worse before they get better.

[Requiem]

Looks like a breezy EURO run at the very least!

[Gradient Keeper]

Day 7

[SouthHillFrosty]

baby steps....baby steps...

[Gradient Keeper]

Day 8

[Gradient Keeper]

Day 9'er

[Phil]

00z Euro also more amped with the WAFz/SSW and Eurasian Arctic ridging.

[AbbyJr]

39 minutes ago, Phil said:

Not sure if anyone linked this but for those seeking Dr. Ventrice’s video here it is.

For those seeking instant gratification, start watching at ~ 34 minutes in. I really do like his analysis here including the EOFs to differentiate wave structures and their long term evolution.

FWIW his projection for PNW ~ 40mins in fits very well w/ the timeline we’ve all discussed.

 

 

Thanks for posting.

I haven't watched it all yet. I'm at around 42 minutes into it. Its an awesome video and very interesting.

He provides evidence that Siberian SSW favour the PNW much more so then North Atlantic ones.

I feel even more confident in my prediction for a cold and snowy pattern in the PNW mid or late January.

Seems highly unlikely things don't work out based on the SSW combined with a -ENSO/+QBO state.

Not to mention, the atmosphere is already behaving as it should leading up to a Siberian SSW with the active yet and Alaskan trough.

Exciting times ahead for PNW winter lovers. 

[Gradient Keeper]

00z ECMWF 10 Day Rainfall, Snowfall totals

[Gradient Keeper]

29 minutes ago, DJ Droppin said:

00z GEFS Day 10-16 GIF

500mb Height Anomaly, 200mb Jet. Positive anomalies popping up across the Pacific with the NPAC, WPAC jet retracting and dying. It looks like the models are starting to pick up on the major NPAC pattern change. Here we go!!!!

 

 

@Phil what are your thoughts based on Day 10-16 progression?

[GHweatherChris]

And, next again.

[Phil]

11 minutes ago, DJ Droppin said:

@Phil what are your thoughts based on Day 10-16 progression?

Signal for height rises over the NPAC is legit. Jet retracts mid-Jan and EPO flips.

Models should trend higher with heights over AK/NE-Pacific with time, though I’m sure there’ll be some waffling around as usual.

[Gradient Keeper]

2 minutes ago, Phil said:

Signal for height rises over the NPAC is legit. Jet retracts mid-Jan and EPO flips.

Models should trend higher with heights over AK/NE-Pacific with time, though I’m sure there’ll be some waffling around as usual.

Yup. Thanks.

[snow_wizard]

2 hours ago, AbbyJr said:

The temperature anomolies are not very cold for the PNW though. I assume the 500mb pattern is good but the arctic air has not come down south yet? (Based on the time of the run)

If the 500mb stuff is there the cold will come.

[snow_wizard]

25 minutes ago, Phil said:

Signal for height rises over the NPAC is legit. Jet retracts mid-Jan and EPO flips.

Models should trend higher with heights over AK/NE-Pacific with time, though I’m sure there’ll be some waffling around as usual.

I was extremely pleased with the GFS operational and GEFS tonight.  Very clear signal for good things to come.

[snow_wizard]

33 minutes ago, GHweatherChris said:

And, next again.

The things we want to see happen to lead to a good pattern for us happen on tonight's runs.  Good enough for now.

[snow_wizard]

56 minutes ago, Phil said:

00z Euro also more amped with the WAFz/SSW and Eurasian Arctic ridging.

I've been seeing the WAFz talked about some lately.  I must admit I'm not sure what that is.

[Phil]

5 minutes ago, snow_wizard said:

I've been seeing the WAFz talked about some lately.  I must admit I'm not sure what that is.

Upward (z-component) of wave activity flux(es). IE: Fluxes into the stratosphere, which can disrupt the vortex.

FYI: Zonal component is denoted by “u” and meridional by “v”. 

[snow_wizard]

5 minutes ago, Phil said:

Upward (z-component) of wave activity flux(es). IE: Fluxes into the stratosphere, which can disrupt the vortex.

FYI: Zonal component is denoted by “u” and meridional by “v”. 

 

I knew about the U, but not the others.  Thanks!

[GHweatherChris]

21 minutes ago, snow_wizard said:

The things we want to see happen to lead to a good pattern for us happen on tonight's runs.  Good enough for now.

Nothing will be good enough until a 00z run shows a substantial amount of snow for my backyard starting before the run ends.

[snow_wizard]

The EPS has the same idea as the GFS and GEFS except it's just a little bit slower.  Brief ridge sets up over us as above normal heights bridge between the mid and high latitudes and then the Pacific Jet retracts quickly.  This all dovetails with what the ECMWF weeklies showed a couple of days ago and what the extended GFS ensemble has been showing.  Intriguingly the 0z EPS speeds up the process as compared to the 12z.  Looks promising.  

[snow_wizard]

All of this business of people giving up on winter in late December is just absurd, but to each his own I guess.

[snow_wizard]

The SSW is progressing nicely BTW.  Pretty good considering the naysayers who kept saying it was never getting any closer!

[GHweatherChris]

1 hour ago, snow_wizard said:

All of this business of people giving up on winter in late December is just absurd, but to each his own I guess.

Their

[TigerWoodsLibido]

Nothing exciting in the believable range. Hinging hopes on an SSW is going to leave one disappointed. Accept it and move onto 21-22. If we go beyond Jan 14 or so it will be the longest EUG has ever gone without a sub-freezing high, the climate here will continue to get more boring for the rest of our lives. It is what it is.

Most vivid weather memories are the Labor Day fires and our coldest temp so far was in late October. What a disaster.

[Meatyorologist]

06z GFS Init.

Off we go. Let's get some eye candy tonight!

[Meatyorologist]

06z GFS Day 1

(Past 4 runs)

[Meatyorologist]

06z GFS Day 2

(Past 4 runs)