May 2016 Observation and Model Discussion for the Pacific Northwest

[snow_wizard]

We were down in Bend yesterday. Rolled into town around 5pm for some Deschutes Brewery after an early hike on the McKenzie River, and apparently we missed one hell of a thunderstorm earlier.

 

Here is a picture from facebook of the hail south of Bend along highway 97, near Lava Butte. I guess it was close to marble sized, and several inches accumulated.

 

Lava Butte Hail.jpg

 

The colder air is really putting up a battle now to become dominant.  After such a long reign of warmth it's not too surprising to see some major fireworks going on.

 

Very impressive pic BTW!

[snow_wizard]

12z EURO looks great. Definitely a nice, troughy run of things the next 7-10 days.

 

I think out nightmare is nearly over!  Yee hawww!!!

 

Nice to see the ridging just off the coast and the trough right over us.  More cool and less wet than a trough a bit further west.

[Phil]

The 12z EPS goes right back into a ridge pattern day 10-15, depicting a discontinuous retrogression signal. Lots of people (as well as the modeling itself) are rushing what will be multi-month pattern transition, as opposed to a simple coin flip.

 

While this'll is probably nothing more than a transient trough post-RWB/EPO, it does mark the beginning of a tendency (offshore height rises/-PNA) that'll gradually and systematically become more frequent over the next 8-10 weeks, finally locking in sometime in mid/late July.

 

 

[snow_wizard]

The 12z EPS goes right back into a ridge pattern day 10-15, depicting a discontinuous retrogression signal. Lots of people (as well as the modeling itself) are rushing what will be multi-month pattern transition, as opposed to a simple coin flip.

 

 

Certainly possible, but it's sure nice to see the cool interludes now.  The 12z operational ECMWF certainly makes that ensemble look dubious though.

[Jesse]

I think out nightmare is nearly over!  Yee hawww!!!

 

Nice to see the ridging just off the coast and the trough right over us.  More cool and less wet than a trough a bit further west.

 

Yup, I really like the details of the upcoming pattern. There seems to be a gradual shift back to troughs actually being capable of giving us sustained NW flow as opposed to the constant SWrly stuff of the last few years. A strengthening high offshore definitely helps this along.

[Phil]

Certainly possible, but it's sure nice to see the cool interludes now. The 12z operational ECMWF certainly makes that ensemble look dubious though.

Anything is possible, though I'd just keep in mind the fact that both humans and modeling tend to rush subseasonal/seasonal pattern changes, for a slew of reasons. I've seen it play out enough times that I (usually) hedge later than the general consensus, by design.

 

The d10-d15 EPS members almost unanimously revert to warm/dry as the jet under the anticyclonic break retracts. Again, temporary, but the back/forth will continue as the large scale deck reshuffles.

[Jesse]

Anything is possible, though I'd just keep in mind the fact that both humans and modeling tend to rush subseasonal/seasonal pattern changes, for a slew of reasons. I've seen it play out enough times that I (usually) hedge later than the general consensus, by design.

 

Totally understandable. I definitely don't think we are out of the woods as far as sustained periods of warmth and ridging goes just yet. I do think that it is quite possible that cool interludes such as the upcoming one become more numerous and more sustained as the months go on, though. It sounds like that is what you are thinking too.

[Phil]

Back in late March/early April, many forecasters were predicting a continuation of the general Niño/+AAM base. Now the opposite is true, with strong/super Niña predictions being thrown around here and there.

 

Very easy to get sucked up in shorter term swings in guidance. I've been guilty of that myself, many times already, in my young life.

[Jesse]

12z Euro ensembles seem to keep us in a pretty troughy pattern through day 10, for whatever that's worth.

[Phil]

Totally understandable. I definitely don't think we are out of the woods as far as sustained periods of warmth and ridging goes just yet. I do think that it is quite possible that cool interludes such as the upcoming one become more numerous and more sustained as the months go on, though. It sounds like that is what you are thinking too.

Oh, I definitely agree with you here. I also anticipate these tendencies will gradually become more frequent over the next 8-10 weeks as we transition away from the Niño/+AAM base, and eventually will become the dominant background pattern sometime in mid/late July, +/- 2 weeks.

 

I just wouldn't expect a sudden flip or anything like that. Very rare to see background forcing change abruptly like that, with most of the rare exceptions occurring during/after mid/late winter SSW events, which can disrupt the upper level equator-pole mass flux/thermal balance conduits, igniting MJO/destructive propagatory forcing capable of destroying a low frequency ENSO/background state, very quickly.

 

This actually occurred in January 2013, and marked the beginning of a prolonged/significant swing in the NPAC/IO-WPAC circulations, leading to a multiyear +AAM/+PDO/+ENSO. Generally, abrupt shifts in background forcing indicate a major shake-up in the works.

[Phil]

The major SSW/MJO in January of 2007 also marked a prolonged transition into the -AAM/-ENSO/-PDO observed thereafter.

 

For what it's worth, research has found that these events involving the rapid destruction of a background regime resonate/correlate well with the solar cycle (always occurring near maximum/minimum), so they might be predictable. Some good papers exist on all this, however our mechanistic reasoning is very hypothetical as of now, given our limited understanding on the nature of interdecadal/multidecadal climate change.

[Jesse]

Looks like PDX could score another sub-60 high.

[Front Ranger]

Remember all that warmest May on record talk a few days ago?

[Deweydog]

Remember all that warmest May on record talk a few days ago?

 

Probably was related to the fact it was really warm.

 

We'll have to look into it.  

[Front Ranger]

Probably was related to the fact it was really warm.

 

We'll have to look into it.

Months that start off warm don't always end warm. Just ask Tim.

[Jesse]

Remember all that warmest May on record talk a few days ago?

 

PDX is still a degree warmer than their warmest May on record, as of today.

 

Let's not get ahead of ourselves.

[James Jones]

Months that start off warm don't always end warm. Just ask Tim.

Crazy for anybody to think that a record warm month might have been possible considering how cold the last 2-3 years have been. We should have known better.

 

But yes, this is a nice crash with some much needed rain.

[Deweydog]

Months that start off warm don't always end warm. Just ask Tim.

 

We'll have to look into this too.  We're gonna be busy!

[SilverFallsAndrew]

NWS Pendleton has a local storm report of 1.00" quarter size hail with depths up to 6.00" inches on roads in Dale in Umatilla County yesterday!

I love the area up around Dale. They get a lot of big t-storms up there. I went up there in the summer of 2012 and they had just had a big run of T-storms. All that is really there is a ramshackle country store. The guy who owns it is very friendly.

[SilverFallsAndrew]

I noticed Salem and Portland are running about 25% above average on precip for the water year. Eugene is about 2" below average. 

[Front Ranger]

PDX is still a degree warmer than their warmest May on record, as of today.

 

Let's not get ahead of ourselves.

 

I think that goes both ways. 

[Front Ranger]

Crazy for anybody to think that a record warm month might have been possible considering how cold the last 2-3 years have been. We should have known better.

 

But yes, this is a nice crash with some much needed rain.

 

Not crazy, but it's always too early to be assuming a record month is likely 7-10 days in. 

 

That's like assuming the Seahawks will go to the Super Bowl if they start out this upcoming season 5-0, blowing everyone out. Sure, they've been to the Super Bowl a lot recently, but a lot can still happen after 5-0.

 

Same thing with a month that starts out really warm or cold.

[TT-SEA]

Its been raining or drizzling here nonstop since yesterday morning.

 

Absolutely sopping wet out there and any grass areas that were looking dry now look lush green.

 

The family that bought the lot next to us have been clearing trees for a house pad and they have permission to continue burning now after a few days of being told to stop. Zero chance of a problem in these conditions.

[Jesse]

Not crazy, but it's always too early to be assuming a record month is likely 7-10 days in.

 

That's like assuming the Seahawks will go to the Super Bowl if they start out this upcoming season 5-0, blowing everyone out. Sure, they've been to the Super Bowl a lot recently, but a lot can still happen after 5-0.

 

Same thing with a month that starts out really warm or cold.

Given the way things have gone lately, and how ridiculously warm the first few weeks of May were, it was by no means a silly call.

[Front Ranger]

500mb heights are above normal over us for every frame of the 00z GFS, and this run isn't an outlier. Looking like this month could contend for a record warm May in a lot of places.

 

Feels silly to say that on the 3rd of the month, but record warmth has been so easy to come by recently that I can't help but think it's a good possibility.

 

 

This month is certainly an easy call in that regard. Probably July, August, and October as well, since that's an annual thing now.

 

 

Who said I wasn't? Just commenting on the models. Notable that we are likely to see another record warm month

 

 

Given the way things have gone lately, and how ridiculously warm the first few weeks of May were, it was by no means a silly call.

 

People, yourself included, were making that call during the first week of the month.

 

Too early. Doesn't matter how easy record months seem to come these days (especially at UHI-aided stations), that's always too early.

[Jesse]

People, yourself included, were making that call during the first week of the month.

 

Too early. Doesn't matter how easy record months seem to come these days (especially at UHI-aided stations), that's always too early.

I don't see the issue. I said it was looking likely. Here we are mid-month and we are still over a degree above the warmest May on record at PDX. Warmest spring on record so far too.

 

The troughy pattern could easily last only another week or so with the month ending on a warm note. Definitely not outside the realm of possibility. In which case it could be argued that you are discounting these calls and making an issue out of nothing too early.

[James Jones]

People, yourself included, were making that call during the first week of the month.

 

Too early. Doesn't matter how easy record months seem to come these days (especially at UHI-aided stations), that's always too early.

It happens. This is a forum full of weather weenies who like to discuss the weather, and it looked like another record warm month could have been on tap, so we talked about it. People goof once in a while. I seem to remember you calling for an average summer last year, for example.

[SilverFallsAndrew]

Raining for about 36 hours straight here. Not much on radar at the moment, but the heaviest rain of the weekend is falling...

[TT-SEA]

Raining for about 36 hours straight here. Not much on radar at the moment, but the heaviest rain of the weekend is falling...

 

 

Exact same thing here.   

[BLI snowman]

I don't see the issue. I said it was looking likely. Here we are mid-month and we are still over a degree above the warmest May on record at PDX. Warmest spring on record so far too.

 

The troughy pattern could easily last only another week or so with the month ending on a warm note. Definitely not outside the realm of possibility. In which case it could be argued that you are discounting these calls and making an issue out of nothing too early.

Yeah, unless I'm suddenly crazy, the monthly record could still very well be in play if the month ends on another hot note. We are still well on pace to set it right now and it will take some more than a couple of slightly cold days before we are really out of the running.

[Front Ranger]

I don't see the issue. I said it was looking likely. Here we are mid-month and we are still over a degree above the warmest May on record at PDX. Warmest spring on record so far too.

 

The troughy pattern could easily last only another week or so with the month ending on a warm note. Definitely not outside the realm of possibility. In which case it could be argued that you are discounting these calls and making an issue out of nothing too early.

It just seemed a bit ironic for you to say "let's not get ahead of ourselves".

 

Not a big deal.

[Front Ranger]

Yeah, unless I'm suddenly crazy, the monthly record could still very well be in play if the month ends on another hot note. We are still well on pace to set it right now and it will take some more than a couple of slightly cold days before we are really out of the running.

Sure, it could still happen at PDX or SEA. Not likely, but possible. As we all know, record* months happen at those two stations much easier.

 

Highly unlikely just about everywhere else.

[Jesse]

It just seemed a bit ironic for you to say "let's not get ahead of ourselves".

No more ironic than you prematurely chastising some for their forecasts a few weeks ago, when in fact this month would have to pull off some pretty impressive cold acrobatics in the next couple weeks to even drop out of the top 3 warmest on record. And even that is far from a sure thing. The last week of the month could still easily go warm. We tend to pay big for these relatively brief flirtations with near to slightly below average lately.

[Front Ranger]

[Deweydog]

FINALLY drying out.

[Anti Marine Layer]

So I can kind of understand why some people in the Pac NW like troughing and coolness throughout the summer. It is such a common thing for most of the year that their bodies are not accustomed to heat, even in the upper 80s. In Phoenix, OTOH, a 90 degree summer day is a treat from heaven when it's normally 110 degrees outside.

 

Same reason I don't like the May Gray/June Gloom. We are so accustomed to sunshine here that to that one straight week with little or no sunshine is hard to take. Californians are some of the most spoiled people in the world - sun worshipers. Not all of us however. 

 

I actually like rain sometimes. It's fun to watch and it usually cleans out the smog behind it and makes the normally brown hills green. In June though, it can be overcast for days with nothing but a few drops of drizzle and the hills stay brown and the air remains polluted. The rest of the country is enjoying pools and beaches, and we're like "When is summer coming?"Then all of a sudden in July it gets hot, and it's still smoggy.

[Jesse]

[Front Ranger]

I hear backpedaling!

I hear the unfortunate sounds of premature speculation.

[Front Ranger]

So I can kind of understand why some people in the Pac NW like troughing and coolness throughout the summer. It is such a common thing for most of the year that their bodies are not accustomed to heat, even in the upper 80s. In Phoenix, OTOH, a 90 degree summer day is a treat from heaven when it's normally 110 degrees outside.

 

Same reason I don't like the May Gray/June Gloom. We are so accustomed to sunshine here that to that one straight week with little or no sunshine is hard to take. Californians are some of the most spoiled people in the world - sun worshipers. Not all of us however.

 

I actually like rain sometimes. It's fun to watch and it usually cleans out the smog behind it and makes the normally brown hills green. In June though, it can be overcast for days with nothing but a few drops of drizzle and the hills stay brown and the air remains polluted. The rest of the country is enjoying pools and beaches, and we're like "When is summer coming?"Then all of a sudden in July it gets hot, and it's still smoggy.

I just don't understand people who only want one kind of weather all of the time. Give me variety, seasons, change, etc.

 

But...people are different.

[Jesse]

I hear the unfortunate sounds of premature speculation.