May 2026 Weather In The PNW

[Port Angeles Foothiller]

1 hour ago, TT-SEA said:

Hmmmm... one day barely reaching 70 and then barely reaching 60 per the ECMWF AIFS.

Post the new run.

[TT-SEA]

1 hour ago, SeattleSmokeLayerFan said:

This Saturday is rock bottom.. and it could run warmer than shown like it usually does. Clouds look to break up in the afternoon and leave us with popcorn thunderstorm like showers.

That's Day 7. After that it warms back up to the 70s and continues to climb from there.

FWIW... this is exactly what the ECMWF is showing.   I really didn't expect it to stick to its guns and it still might cave but glad to see the 00Z run held.

[TT-SEA]

Just now, Port Angeles Foothiller said:

Post the new run.

00Z ECMWF AIFS is the same as its previous runs... highs barely reaching 60 during the middle of next week.   

[Port Angeles Foothiller]

17 minutes ago, TT-SEA said:

ECMWF still looks the best scenario by far for next week.    Hope its still the king! 

 

[Port Angeles Foothiller]

1 minute ago, TT-SEA said:

00Z ECMWF AIFS is the same as its previous runs... highs barely reaching 60 during the middle of next week.   

Day 10 + look to be trending to the warm cluster. 

[TT-SEA]

1 minute ago, Port Angeles Foothiller said:

Day 10 + look to be trending to the warm cluster. 

Yes... ECMWF AIFS turns warm by about day 12.   ECMWF just skips the troughing reload next week and warms up 4 or 5 days earlier.  

[SeattleSmokeLayerFan]

9 minutes ago, Port Angeles Foothiller said:

Day 10 + look to be trending to the warm cluster. 

This is what I pointed out earlier with the information loss in taking the average of individual members/operational runs in the long range. The ensemble average is usually regressed to the mean after D10... But as we get closer we should see it trend towards the correct cluster, which has been dominantly warm.

[Meatyorologist]

I'm thinking we get both these next two troughs, then dive into extended heat. Much like tracking an arctic blast in the winter, the Euro is jumping the gun early on a pattern change. These kinds of meta-trends across model runs are the exact kind of thing AI counterparts resolve well. And, lo and behold, on the AI Euro we get a cohesive rainstorm with heights below normal after this next trough.

[Phil]

3 hours ago, TT-SEA said:

Yes... ECMWF AIFS turns warm by about day 12.   ECMWF just skips the troughing reload next week and warms up 4 or 5 days earlier.  

Someone fill me in on why we’re debating D12 right now?

The intraseasonal tropical forcing progression and its known influence on wavetrains/hemispheric scale patterns is more valuable than any deterministic model run (or even physics based ensemble run, IMO, which is why the AI ensemble mean is so good in the LR).

[Phil]

3 hours ago, Meatyorologist said:

I'm thinking we get both these next two troughs, then dive into extended heat. Much like tracking an arctic blast in the winter, the Euro is jumping the gun early on a pattern change. These kinds of meta-trends across model runs are the exact kind of thing AI counterparts resolve well. And, lo and behold, on the AI Euro we get a cohesive rainstorm with heights below normal after this next trough.

This isn’t 2015. It won’t be cool/troughy forever but there’s enough westerly momentum being deposited into the middle latitudes to keep things changeable/quasi-progressive for awhile.

End result is probably a mediocre positive temp departure with frequent ups and downs.

[Doom Buster]

Final departures and rankings for May.

BLI: +1.4, 12th warmest

SEA: +.9, 13th warmest

OLM: +1.6, 19th warmest

PDX: +2.2, 9th warmest

SLE: +1.9, 14th warmest

EUG: +1.5, 19th warmest

[Phishy Wx]

transitional wx is transitional

[Phishy Wx]

what's the preferred winter LOG at this early point so far?  Anyone on to something yet?

[StormchaserChuck1]

12 hours ago, Phil said:

The PDO is essentially useless unless you detrend the SSTAs. Otherwise it’s biased artificially negative. 

I don't agree with that, we had a really big +PDO spike 2014-16. PDO is a 50/50 index. 

[StormchaserChuck1]

20 minutes ago, Phishy Wx said:

what's the preferred winter LOG at this early point so far?  Anyone on to something yet?

I would say 23-24, matches the east-based Nino and -PDO. Maybe 72-73 as number 2. Dec 2015 matches the QBO. 

[BLI snowman]

27 minutes ago, StormchaserChuck1 said:

I would say 23-24, matches the east-based Nino and -PDO. Maybe 72-73 as number 2. Dec 2015 matches the QBO. 

Unfortunately the amount of climate change we've seen since 1972 renders it pretty useless as an analog. Dramatically different time. 

An outcome as cold as 2015-16 would probably be a pretty favorable one for the CONUS this year, all things considered. 

[Phishy Wx]

72-73 was a huge turd anyway.  23-24 and 15-16 were below normal in snow, but not excessively.  15-16 featured the snowiest December in Spokane since 08-09 and the snowiest since then

[StormchaserChuck1]

3 hours ago, BLI snowman said:

Unfortunately the amount of climate change we've seen since 1972 renders it pretty useless as an analog. Dramatically different time. 

An outcome as cold as 2015-16 would probably be a pretty favorable one for the CONUS this year, all things considered. 

Yeah, even 1997 is kind of far back now

[BLI snowman]

14 minutes ago, StormchaserChuck1 said:

Yeah, even 1997 is kind of far back now

Yeah, I genuinely don't think a summer like that would be possible today unfortunately.

And winter 1997-98 was a slightly colder version of 2015-16 nationally. The shoulder months of November 1997 and March 1998 actually had some chilly weather nationally which I doubt we'll see to the same extent this coming year.

Even mega Niño years like that are a reminder of how much warmer a baseline we are working with now several decades later. 

[StormchaserChuck1]

A big problem is Strong El Nino's are not spinning up a massive North Pacific low like they used to. Whether we are in a -ENSO/-PDO decadal state, or maybe the jet stream is just lifting north in general, the same thing is happening with this El Nino so far. May is usually a decently correlated month:

And it's been all -PNA

[Phil]

4 hours ago, StormchaserChuck1 said:

I would say 23-24, matches the east-based Nino and -PDO. Maybe 72-73 as number 2. Dec 2015 matches the QBO. 

100% disagree. That event developed entirely differently (EPAC conduit), had opposite QBO, and opposite PMM/AMM dipoles.

Couldn't think of a worse Niño analogy, actually.

[Phil]

5 hours ago, Phishy Wx said:

what's the preferred winter LOG at this early point so far?  Anyone on to something yet?

Some variably-weighted pool of 1957/58, 1982/83, 1991/92, 2002/03, and 2015/16.

I’m starting to like 1957/58 more, but the placement in the solar cycle gives me some pause for the QBO method I employ.

[Phil]

28 minutes ago, StormchaserChuck1 said:

A big problem is Strong El Nino's are not spinning up a massive North Pacific low like they used to. Whether we are in a -ENSO/-PDO decadal state, or maybe the jet stream is just lifting north in general, the same thing is happening with this El Nino so far. May is usually a decently correlated month:

And it's been all -PNA

That’s a myth. 2015/16 had as potent an Aleutian Low as any Niño in the modern era (save 97/98).

 

[Phil]

The actual problem is strong/super Niños have been relatively rare thus far in the 21st century, so our brains revert to recency bias. We’ve only had 2 truly powerful Niños in the last 26+ years, and one of them (2023/24) developed via a conduit not observed since the 1970s, which rendered the global state unfavorable for a potent Aleutian Low

Unlike 2023/24, the mean state will actually be favorable for a strong Aleutian Low this winter, similar to 2015/16 and most of the super Niños during the second half of the 21st century.

[Omegaraptor]

27 minutes ago, Phil said:

Some variably-weighted pool of 1957/58, 1982/83, 1991/92, 2002/03, and 2015/16.

I’m starting to like 1957/58 more, but the placement in the solar cycle gives me some pause for the QBO method I employ.

Torchiest anomalies will probably be after February 1st this time, from the looks of it. Hard to get a more hostile analog pool for late season cold and snow than this.

Background state will probably be hot garbage but it's not impossible that things line up right for a week or so at some point Dec 10 - January 20. This season's mountain snowpack was once in a generation level awful, I can't imagine there's a strong chance next season will be quite as bad. If it is, good luck to the ecosystem, lol.

[Phishy Wx]

2 hours ago, Phil said:

Some variably-weighted pool of 1957/58, 1982/83, 1991/92, 2002/03, and 2015/16.

I’m starting to like 1957/58 more, but the placement in the solar cycle gives me some pause for the QBO method I employ.

D**n thats a plate of turds.  woof

[Doom Buster]

On 5/31/2026 at 9:45 AM, BLI snowman said:

Also looks like a very good chance that we see 90 down here on Tuesday. Tomorrow will probably fall just short. 

 

If 6 degrees is just short, great call!

[BLI snowman]

32 minutes ago, Doom Buster said:

If 6 degrees is just short, great call!

Brrrr! Cold times 2026! We keep spending most our lives living in a Flatiron Paradise!

[StormchaserChuck1]

3 hours ago, Phil said:

That’s a myth. 2015/16 had as potent an Aleutian Low as any Niño in the modern era (save 97/98).

Big difference between +PDO Strong Nino's and -PDO Strong Nino's. That's what you call "statistical relevance". Even 18-19 was completely -PNA. 

[Phil]

12 hours ago, StormchaserChuck1 said:

Big difference between +PDO Strong Nino's and -PDO Strong Nino's. That's what you call "statistical relevance". Even 18-19 was completely -PNA. 

Firstly that is a goalpost shift from “Niños don’t produce Aleutian Lows anymore”.

Secondly, the “PDO” has zero effect on the atmosphere so that is irrelevant. It is really the IPWP-PMM dipole you are looking at for that correlation, it leads ENSO substantially and affects low frequency atmospheric circulation enough to modify NPAC SSTAs before the ENSO response, giving the illusion of PDO as a leading forcing when in fact it is an echo of external/tropical forcing.

I don’t care how many times people try to argue that PDO correlation, it is an illusion borne out by poor statistics, spatial analysis, and one dimensional thinking.  

[Phil]

Hear me now, quote me later. This winter will indeed have a strong Aleutian Low (barring some wildly unlikely collapse of the Niño), and those relying on PDO weighted analog pools will come to believe the correlation somehow got “broken”, when in reality it was never there to begin with.

[Doom Buster]

12 hours ago, BLI snowman said:

Brrrr! Cold times 2026! We keep spending most our lives living in a Flatiron Paradise!

False Dilemma (Either/Or)

• What it is: Presenting a complex situation as having only two alternatives, when in fact there are many other options.

[TigerWoodsLibido]

1 hour ago, Phil said:

Hear me now, quote me later. This winter will indeed have a strong Aleutian Low (barring some wildly unlikely collapse of the Niño), and those relying on PDO weighted analog pools will come to believe the correlation somehow got “broken”, when in reality it was never there to begin with.

Good ol uncle AL with us all “winter”

[StormchaserChuck1]

6 hours ago, Phil said:

Firstly that is a goalpost shift from “Niños don’t produce Aleutian Lows anymore”.

Secondly, the “PDO” has zero effect on the atmosphere so that is irrelevant. It is really the IPWP-PMM dipole you are looking at for that correlation, it leads ENSO substantially and affects low frequency atmospheric circulation enough to modify NPAC SSTAs before the ENSO response, giving the illusion of PDO as a leading forcing when in fact it is an echo of external/tropical forcing.

I don’t care how many times people try to argue that PDO correlation, it is an illusion borne out by poor statistics, spatial analysis, and one dimensional thinking.  

Larger scale things probably influence the PDO. PDO actually has higher correlation over the US than ENSO, and that's over 80 years of data. PMM is a SSTA variable too, and you use that a lot. Just like other Pacific SSTA's. It's easy to describe things that way. I agree that water is heavier than air and surface water anomalies pretty much have no primary impact. 

I wasn't really tracking 2015, so I overlooked that big Aleutian Low. You're right, but since 2016 we've never seen an El Nino with big Aleutian low, this is the 3rd event. I know it's early but May typically has 0.5-0.7 correlation numbers in the North Pacific, which didn't happen this May. It's looking like we won't see a 1997 and 2015 type North pacific low this El Nino (I could be wrong it's early), and that rings "PDO" too me. That was my train of thought. 

[StormchaserChuck1]

6 hours ago, Phil said:

Hear me now, quote me later. This winter will indeed have a strong Aleutian Low (barring some wildly unlikely collapse of the Niño), and those relying on PDO weighted analog pools will come to believe the correlation somehow got “broken”, when in reality it was never there to begin with.

Average for Super Nino is -120dm mean (DJF)!

Average for Strong Nino is -80dm mean (DJF)

Over or under? 

I'll say it won't be that strong of a N. Pacific low. Actually I'd be surprised if we deviate very far from neutral. 

[Doom Buster]

On 5/16/2026 at 3:52 PM, ShawniganLake said:

Yes. With hail. ~0.4” so far.  

 

On 5/25/2026 at 11:49 PM, ShawniganLake said:

A few downpours moved through from the south later in the day.  0.23” here today.  

I knew I remembered it! Significantly better than Victoria.

[ShawniganLake]

4 minutes ago, Doom Buster said:

 

I knew I remembered it! Significantly better than Victoria.

You didn’t have to dig it up. I answered in the other thread. We were one of the wettest spots with 35% of normal precip. 0.71” I believe.  Shawnigan lake is a wetter climate than most of Victoria.  

[Doom Buster]

Just now, ShawniganLake said:

You didn’t have to dig it up. I answered in the other thread. We were one of the wettest spots with 35% of normal precip. 0.71” I believe 

It didn't take long, I was just checking to make sure I remembered correctly. Found those posts before your answer.