January Weather In the PNW

[Phil]

I was looking at the daily numbers for the periods the cold events actually happened. Not monthly numbers.

We that’s not very helpful IMO. The atmospheric dynamics responsible for these events are playing out several weeks before the Arctic blasts in question.

[Gradient Keeper]

Day 9

http://maps1.pivotalweather.com/maps/models/ecmwf/2018010900/216/500h_anom.na.png

[Gradient Keeper]

Euro is considerably deeper, further south than GFS with the approaching trough at day 7.

Yup, and Ridge over Aleutians Day 8-9 more amplified. This run just might bring Jim back to the Forum

[Phil]

Check out the 850mb temp map on day 8.

 

What a joke.

I see a + 63*F anomaly in Alaska. Yikes.

 

Way too much Southwest flow. The 24hr-averaged 2m temperature anomalies are well above average.

[Gradient Keeper]

Day 10

http://maps1.pivotalweather.com/maps/models/ecmwf/2018010900/240/500h_anom.na.png

 

[SilverFallsAndrew]

So have the Patriots... but you cheer for them every year anyways.

 

That is mostly due to Tom Brady's handsome looks.

[Front Ranger]

I’ve been saying all winter that +NAO would teleconnect to +PNA on the low frequency, because that’s what history says happens in warm pool dominated winters. So far that has held true, even more-so than I thought it would.

 

If the PNA does go negative, I’ll bet you dollars to donuts that the NAO will, as well.

 

 

I’d put it this way. In any year, a +NAO (especially a west-based +NAO coupled to the stratosphere) is detrimental to Arctic chances in the PNW.

 

However, it can be overcome more easily in some years relative to other years. Rare to get a “perfect” pattern, so that’s never necessary, but progressive patterns lacking amplification are usually the culprit for failure west of the Cascades, and it’s easier to slow the streamflow when you have blocks both upstream and downstream.

 

 

We that’s not very helpful IMO. The atmospheric dynamics responsible for these events are playing out several weeks before the Arctic blasts in question.

 

Look at what you said above. Sure sounds like you're talking about +NAO/-NAO occurring during the actual patterns in question.

[Phil]

Look at what you said above. Sure sounds like you're talking about +NAO/-NAO occurring during the actual patterns in question.

Huh? How so? I’m speaking broadly about the state of the boreal winter NAO and how it may affect the NPAC wavetrain (and by consequence, Arctic opportunities in the PNW).

[Front Ranger]

Day 10

http://maps1.pivotalweather.com/maps/models/ecmwf/2018010900/240/500h_anom.na.png

 

 

 

The good news is that models are generally wanting to start kicking the Aleutian low out by day 8 and moving in a ridge in that area. The Euro also starts moving a big chunk of cold air westward across Canada at the end, as the blocking configuration becomes more favorable to the north.

[Front Ranger]

Huh? How so? I’m speaking broadly about the state of the boreal winter NAO and how it may affect the NPAC wavetrain (and by consequence, Arctic opportunities in the PNW).

 

You said "if the PNA goes negative, I bet the NAO will too". Or did you mean the NAO would too, but several weeks later?

[Phil]

The connection to the tropics is pretty fantastic in regards to this pattern swing. I might even have to start a thread about it.

 

We’ll have the intraseasonal/MJO forcing in La Niña mode for another ~ 3 weeks, so this window is limited to some extent. Still, there’s some potential if blocking is sufficient going forward (never a given).

[Front Ranger]

The connection to the tropics is pretty fantastic in regards to this pattern swing. I might even have to start a thread about it.

 

We’ll have the intraseasonal/MJO forcing in La Niña mode for another ~ 3 weeks, so there’s some potential during this period if blocking is sufficient.

 

So you've no longer written off January? 

[Bryant]

 

Looks exactly like you'd expect with the pattern at that point. Below normal 850s for much of OR/northern CA, warmer to the north.

Tim is just being Tim

[Phil]

You said "if the PNA goes negative, I bet the NAO will too". Or did you mean the NAO would too, but several weeks later?

I’m referring to mean NAO/PNA states on a multiweek resolution. It’s not (necessarily) an immediate/short term resonance since it takes some time wavetrain changes to communicate spatially.

[Phil]

So you've no longer written off January?

I never wrote off January. Just the 8-10 days with the extended jet/+PNA.

 

It’s threading the needle, though. Race against the clock before tropical forcing leaves its Niña state again at the end of the month.

[Front Ranger]

I’m referring to mean NAO/PNA states on a multiweek resolution. It’s not (necessarily) an immediate/short term resonance since it takes some time wavetrain changes to communicate spatially.

 

Ok. I guess as long as we agree that +NAO occurring does not prevent the PNW from getting cold while it is occurring. 

[Phil]

Ok. I guess as long as we agree that +NAO occurring does not prevent the PNW from getting cold while it is occurring.

It doesn’t prevent the PNW from getting cold, period.

 

It just makes it more difficult to score Arctic blasts, especially in -QBO/Niña and +QBO/Niño. That doesn’t mean it’s impossible.

[Front Ranger]

Well, I have given up on an Arctic blast this month in the PNW. I haven’t given up on February yet. There’s some potential there, IMO, but it’s threading the needle.

 

 

I never wrote off January. Just the 8-10 days with the extended jet/+PNA.

 

It’s threading the needle, though. Race against the clock before tropical forcing leaves its Niña state again at the end of the month.

 

Ok, Phil. You say a lot of things...hard to keep track of, but not impossible.

[Phil]

Ok, Phil. You say a lot of things...hard to keep track of, but not impossible.

I have given up on an Arctic blast this month. I haven’t given up on lowland snowfall, or “written off” the month.

 

I clarified that later on, FWIW.

[Phil]

Though in hindsight, I can definitely see how that could be confusing. Jesse’s “Phil contradicts himself” comment makes more sense now.

 

I’ll try to add edits to my posts (or quote them) going forward, instead of making new posts later that could get mixed up in the thick of things.

[ShawniganLake]

Day 11-15

 

 

Day 15

 

[SilverFallsAndrew]

Night shift!

[SilverFallsAndrew]

Best GFS run in a while. 

[SilverFallsAndrew]

And the ensembles are way worse...

[crf450ish]

33* and rain ontop of 10” of snow at my house. Glorious.

[Farmboy]

33* and rain ontop of 10” of snow at my house. Glorious.

You have little to complain about.

[Deweydog]

Drippy out there!

[SilverFallsAndrew]

In weather related news the GFS pumps more cold into the Eastern 2/3rds in the long range, while meandering split/cutoff lows pump mild SW flow into the PNW. Nina nightmares!

[SilverFallsAndrew]

Drippy out there!

 

0.78" of rain overnight!

[ShawniganLake]

I’m just going to pretend the 12Z GFS didn’t happen.

[Deweydog]

In weather related news the GFS pumps more cold into the Eastern 2/3rds in the long range, while meandering split/cutoff lows pump mild SW flow into the PNW. Nina nightmares!

Phil called it.

[MossMan]

Some bright news in a otherwise dark day both outside and in the modeling world...PNA still looks fantastic with the dip happening just after MLK Day!

[Jesse]

I’m just going to pretend the 12Z GFS didn’t happen.

I think that’s what everyone else was doing.

[van city]

I’m just going to pretend the 12Z GFS didn’t happen.

Lol. Who knows what will happen.

 

[MR.SNOWMIZER]

Good amounts of mountain snow on the 12z. I will take that.

[SilverFallsAndrew]

So basically we get 5-7 days of average to slightly below average temps and a normal amount of mountain snow. Then it is back to the show while the epic eastern winter continues...GREAT...Hoping this was an outlier, but the 06z Ensembles made me sick to my stomach. 

[Deweydog]

We're f*cked.

[MR.SNOWMIZER]

We're f*cked.

Not a dry one though so it wont be to bad.  

[Geos]

Some bright news in a otherwise dark day both outside and in the modeling world...PNA still looks fantastic with the dip happening just after MLK Day!

 

Yeah that looks good. Lets get that PNA down!

It's been consistent with the 17th time frame. 

[Jesse]

12z ensembles weren’t terrible.