September 2017 PNW Discussion Thread

[Phil]

It's no coincidence that the recent stretch of warm years in the PNW corresponded to a dead Atlantic and +NAM background state. The Atlantic is highly coupled to the Indian Ocean, which plays directly on the longitude/intensity of the WPAC/IPWP convection and the entire tropical wavenumber.

 

The Pacific doesn't rule the roost. The roost rules the Pacific.

[wx_statman]

Shades of 2014.

 

That one was pretty impressive.

[Deweydog]

Shades of 2014.

Ur so mean to him.

[Front Ranger]

 

In what respect? If only Pacific forcing mattered, then what explains the sharp pattern differences between years with very similar ENSO/PDO? The Pacific is one piece in an puzzle of interconnected yet non-linear moving parts.

 

Take 2007/08 and 2010/11, for example. Very similar Pacific states, very different fall/winter circulations Same with 2008/09 and 2011/12.

 

Not saying the Atlantic circulation doesn't play a role in North American weather, it's just much smaller than the Pacific. Especially for the West.

[BLI snowman]

Ur so mean to him.

 

We'll always have November 13.

[Front Ranger]

First "Arctic outbreak" pattern of the season underway. Currently 42 with north winds at Cut Bank, with Fraser outflow at BLI. 

 

PDX might even end up below normal today!

[Front Ranger]

The Pacific doesn't rule the roost. The roost rules the Pacific.

 

Rooster > Roost > Pacific > Atlantic > Irma > Phil

[Phil]

Not saying the Atlantic circulation doesn't play a role in North American weather, it's just much smaller than the Pacific. Especially for the West.

It's more about what the Atlantic reflects about the state of the Indian Ocean and EHEM wavetrain, which is a huge deal for western North America. The immediate effect(s) of the tropical cyclones is less important in the long run.

[Phil]

Rooster > Roost > Pacific > Atlantic > Irma > Phil > Flatiron

FYP.

[stuffradio]

It's no coincidence that the recent stretch of warm years in the PNW corresponded to a dead Atlantic and +NAM background state. The Atlantic is highly coupled to the Indian Ocean, which plays directly on the longitude/intensity of the WPAC/IPWP convection and the entire tropical wavenumber.

 

The Pacific doesn't rule the roost. The roost rules the Pacific.

The chicken doesn't hatch the egg, the egg hatches the chicken.

[Chewbacca Defense]

First "Arctic outbreak" pattern of the season underway. Currently 42 with north winds at Cut Bank, with Fraser outflow at BLI. 

Heh, I didn't really think about it that way, but yeah, we do have a pretty good breeze coming out of the N-NE today here in Bellingham.  Just looked at the the observations at KBLI and it has gotten quite gusty over the past few hours.  Looks like there was a gust to 30 at 11:53am, gust to 23 at my house around the same time.

 

Of course the big difference between this outflow and one in January is it has warmed up quite a bit since the winds kicked up (up to 77).  

[stuffradio]

We'll always have November 13.

You may be on to something with you mentioning November. Ben Noll on Twitter today tweeted that the Nino 3.4 has observed its coldest anomaly since late November 2016.

[stuffradio]

Here's another thing about a cold end to September.

 

[Front Ranger]

The chicken doesn't hatch the egg, the egg hatches the chicken.

 

But which came first???

[wx_statman]

Heh, I didn't really think about it that way, but yeah, we do have a pretty good breeze coming out of the N-NE today here in Bellingham.  Just looked at the the observations at KBLI and it has gotten quite gusty over the past few hours.  Looks like there was a gust to 30 at 11:53am, gust to 23 at my house around the same time.

 

Of course the big difference between this outflow and one in January is it has warmed up quite a bit since the winds kicked up (up to 77).  

 

It's definitely more of a warm downslope situation today. 

[Deweydog]

That's a strong-a** jet by Wednesday. Tim may be in mid-season form in less than a week.

[Phil]

Yeah, that's one hell of a trough on the 18z GFS.

[TT-SEA]

That's a strong-a** jet by Wednesday. Tim may be in mid-season form in less than a week.

 

Right.   

 

Not a big deal... we need the rain.   And a strong jet stream is more enjoyable than meandering systems anyways.   

 

Also... the 12Z ECMWF looks like this on the next day.   

 

[Front Ranger]

 

People are commenting on the 18z GFS, so Tim starts posting Euro maps...again.

[Phil]

Blocking galore. Triple anticyclonic wavebreak.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/9FA0E3D5-62A6-47E5-ADE7-0B8F142DC4CD_zpsfujygfc2.png

[TT-SEA]

 

People are commenting on the 18z GFS, so Tim starts posting Euro maps...again.

 

I know.   The 18Z GFS is far superior to the ECMWF and EPS.   Sorry about that.    

[Phil]

Verbatim, future hurricane Lee is beefing up that eastern ridge while the Pacific wavetrain wants to push it out. Would be an interesting and highly unpredictable battle if it were to verify.

[wx_statman]

Verbatim, future hurricane Lee is beefing up that eastern ridge while the Pacific wavetrain wants to push it out. Would be an interesting and highly unpredictable battle if it were to verify.

 

I wonder if the 1926 Miami hurricane gave a tropical assist to the record-breaking cold wave in the Rockies/PNW that month. Something similar to what you're talking about, where it boosted a ridge in the eastern US and caused/enhanced an upstream buckle in the jet stream over western N. America? Just thinking out loud. 

[TT-SEA]

The goofy 18Z GFS is a little slower getting there than the ECMWF and EPS... but it does bring back ridging for the last part of the month as well.

[Jesse]

That's a strong-a** jet by Wednesday. Tim may be in mid-season form in less than a week.

He's already close and the rain hasn't even started yet.

[BLI snowman]

I wonder if the 1926 Miami hurricane gave a tropical assist to the record-breaking cold wave in the Rockies/PNW that month. Something similar to what you're talking about, where it boosted a ridge in the eastern US and caused/enhanced an upstream buckle in the jet stream over western N. America? Just thinking out loud. 

 

It's certainly happened on a number of occasions where strong hurricanes hitting the U.S. have coincided with extreme blocking elsewhere in the country. Of course we recently observed it with Harvey to an extent and the massive ridge over us, but off hand you also have Charley which coincided with the mid August 2004 Midwestern coldwave, Andrew and the late August 1992 airmass, and Kate which coincided with the 2nd arctic airmass in November 1985.

[TT-SEA]

He's already close and the rain hasn't even started yet.

You wish buddy!

[Deweydog]

He's already close and the rain hasn't even started yet.

From a distance, it may be a practically seamless transition from irritable Jesse to irritable Tim. A dynamic month indeed!

[TT-SEA]

From a distance, it may be a practically seamless transition from irritable Jesse to irritable Tim. A dynamic month indeed!

That is usually the case.

 

However... I suspect irritable Jesse is coming back pretty soon after troughing arrives.

 

I think the worst case scenario for the TIM index would be ridgy and hot for all of September. I was getting anxious earlier in the month. I love seeing a deep trough and then another ridge in the models. Hopefully sets the stage for a variable fall and winter.

[Jesse]

From a distance, it may be a practically seamless transition from irritable Jesse to irritable Tim. A dynamic month indeed!

False equivalence. But that's what you do. I shouldn't have opened the door.

[Jesse]

That is usually the case.

 

However... I suspect irritable Jesse is coming back pretty soon after troughing arrives.

 

I think the worst case scenario for the TIM index would be ridgy and hot for all of September. I was getting anxious earlier in the month. I love seeing a deep trough and then another ridge in the models. Hopefully sets the stage for a variable fall and winter.

Are you still going on about the ridge at day 14? Do I spend all summer posting about troughs at day 14? I think that would irritate you.

[Deweydog]

False equivalence. But that's what you do. I shouldn't have opened the door.

You opened the door 10 years ago. Tim opened his first, though.

[wx_statman]

It's certainly happened on a number of occasions where strong hurricanes hitting the U.S. have coincided with extreme blocking elsewhere in the country. Of course we recently observed it with Harvey to an extent and the massive ridge over us, but off hand you also have Charley which coincided with the mid August 2004 Midwestern coldwave, Andrew and the late August 1992 airmass, and Kate which coincided with the 2nd arctic airmass in November 1985.

Yeah, tropical systems look like a very interesting wild card for blocking patterns thousands of miles away. I'm also reminded of when those typhoon remnants barreled into Alaska in November 2014, triggering the jet stream buckle that led to a pretty epic coast to coast cold wave.

[Jesse]

You opened the door 10 years ago. Tim opened his first, though.

Considering how awful this summer has been I don't think I've been that bad. I think you are basing your opinion more off of old memories than how I actually am now. Human nature, I realize.

[wx_statman]

Considering how awful this summer has been I don't think I've been that bad. I think you are basing your opinion more off of old memories than how I actually am now. Human nature, I realize.

 

Watch your mouth, young man. July was beautiful. 

[stuffradio]

Watch your mouth, young man. July was beautiful. 

10-12 days in August were horrible, the rest of the summer was the opposite of awful.

[TT-SEA]

Are you still going on about the ridge at day 14? Do I spend all summer posting about troughs at day 14? I think that would irritate you.

 

 

I think ridge starts building back in around day 7.   

 

And I would not be bothered by trough posts... particularly if it was likely going to happen.    There was not much possibility of that this summer.  

[TT-SEA]

Watch your mouth, young man. July was beautiful. 

 

And June except for a couple days.  

 

And a good chunk of August.

 

And of course July was probably the most pleasant summer possible.    

[Anti Marine Layer]

Deep marine layer here today, but warm ocean temperatures are keeping things from being as cold as they would be in May and June, which actually have a higher sun angle than now.

 

Yes I complain about gloomy weather and people make fun of me that I should think of the situation in Texas and Florida, and I must admit I am a "spoiled brat" sometimes, but I've also seen PNW people complain about heat even when there are no fires to smoke up the air. So it's not only me.

 

Anyway looks like some nice rain up there next week, which will hopefully get all those fires under control.

[Jesse]

I think ridge starts building back in around day 7.

 

And I would not be bothered by trough posts... particularly if it was likely going to happen. There was not much possibility of that this summer.

It's a stretch to say anything 14 days out is "likely". The 18z ensembles don't look ridgy in the long range.