September 2017 PNW Discussion Thread

[seattleweatherguy]

Similar to the Euro seasonal, the JMA seasonal also has an insanely strong NPAC jet during November.

 

Check out these zonal wind anomalies.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/F73AC033-E6A7-4D83-96F2-C55B0F368136_zpsj8h6in5e.jpg

Zonal flow jet like that mean more potential for windstorms in Nov?

[luminen]

That map is messed up.    I doubt the Rocky Mountains were that far west during the last ice age just 15,000 years ago.  

 

 

Kinda OT, but it's crazy to imagine what the climate would have been been like during the last ice age. Sea ice pushing all the way down to Baja California is pretty hard to visualize.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/1939CD82-F9FD-472F-85B7-67337D49BA53_zpsmqiog4c3.jpg

 

I'm 99.9% sure that there'd be more winter sea ice south of Japan and in the Sea of Japan for sure. Today it reaches the Hokkaido coast already, not that far out in the ocean like in this map mind you, but this is pretty inaccurate.

[Phil]

I'm 99.9% sure that there'd be more winter sea ice south of Japan and in the Sea of Japan for sure. Today it reaches the Hokkaido coast already, not that far out in the ocean like in this map mind you, but this is pretty inaccurate.

I think the Sea of Japan (along with the Mediterranean Sea and others) was just left out. The ice coverage depicted here came from a NOAA page with a list of peer reviewed studies below the image, but admittedly, Northwest Pacific sea ice isn't something I've researched enough to hold any worthwhile opinion on.

[wx_statman]

Yeah it is over simplified. Your missing the Vashon Lobe/glacier that pushed all the way to Olympia!

And where is the Sierra Nevada icecap?

[Phil]

It's from the CLIMAP project, which is very coarse in resolution and somewhat outdated. Some of the smaller glaciers are missing.

 

The proxy-based models do paint an interesting picture, with portions of the Subtropical Pacific having SSTs warmer than today:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/933C5ED2-AA8D-4D6C-A0B7-A187653B1860_zps22bcbpp1.jpg

[Phil]

And where is the Sierra Nevada icecap?

I guess this map might be more accurate in terms of land ice coverage.

 

http://www.qpg.geog.cam.ac.uk/images/lgm/LGM_Nord_a.jpg

[wx_statman]

I guess this map might be more accurate in terms of land ice coverage.http://www.qpg.geog.cam.ac.uk/images/lgm/LGM_Nord_a.jpg

That's a cool map.

[Jesse]

New 80+ streak started at PDX today.

[Jesse]

It was at 10. You were late so we wrapped things up without you.

Short ceremony. In contrast to a VERY long 75+ streak. I don't think it did it justice.

[wx_statman]

Short ceremony. In contrast to a VERY long 75+ streak. I don't think it did it justice.

 

I agree. Kevin Martin was acting really weird so the rest of us decided to wrap things up early.

[Jesse]

I agree. Kevin Martin was acting really weird so the rest of us decided to wrap things up early.

You should have stuck around. I'm sure it would have been a blast!

[TT-SEA]

00Z GFS is stronger again with the troughing for the upcoming week and brings in a possible windstorm mid-week.  

 

[seattleweatherguy]

00Z GFS is stronger again with the troughing for the upcoming week and brings in a possible windstorm mid-week.

Wow a windstorm, don't our notable ones happen in neutral years vs la nina though?

[TT-SEA]

Wow a windstorm, don't our notable ones happen in neutral years vs la nina though?

 

 

Can happen any time.   No idea if this would be notable or just a windy system.

[Phil]

00Z GFS is stronger again with the troughing for the upcoming week and brings in a possible windstorm mid-week.

 

Jose is rolling his eye.

[wx_statman]

00Z GFS is stronger again with the troughing for the upcoming week and brings in a possible windstorm mid-week.  

 

 

Jose sitting right off New England is interesting too.

[seattleweatherguy]

Any way to correlate some how our notable windstorms vs just the avg 40 to 50 plus and see if there is a trend?

[TT-SEA]

Jose sitting right off New England is interesting too.

 

Nasty in Boston with a strong east wind and rain.  

[TT-SEA]

Despite a very active 4 days on the 00Z GFS during the work week... it still gets back to the ridging solution for next weekend that was shown on the 12Z runs.

 

[Phil]

The 00z clown range is hilarious. The strongest ridge over the entire Northern Hemisphere is (once again) right over the PNW, and the Greenland vortex wakes up again. After awhile you just have to lol at it.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/D6F3BCCF-58EC-4F48-92E3-C0B9A661AAA9_zpsnglfvmrm.png

[wx_statman]

The 00z clown range is hilarious. The strongest ridge over the entire Northern Hemisphere is (once again) right over the PNW, and the Greenland vortex wakes up again. After awhile you just have to lol at it.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/D6F3BCCF-58EC-4F48-92E3-C0B9A661AAA9_zpsnglfvmrm.png

 

1970 & 1988. Couple precedents in a developing Nina.

[luminen]

The 00z clown range is hilarious. The strongest ridge over the entire Northern Hemisphere is (once again) right over the PNW, and the Greenland vortex wakes up again. After awhile you just have to lol at it.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/D6F3BCCF-58EC-4F48-92E3-C0B9A661AAA9_zpsnglfvmrm.png

 

annoying but not necessarily a bad thing. As the light gets less, warmer weather is actually more welcome than during high summer.

[TT-SEA]

Looks like the smoke is back and will be here until the rain starts tomorrow afternoon per the smoke model.  

 

Also seems to be some agreement on a system Wednesday with heavy rain and some wind.    

[Jbolin]

Beautiful sunrise this morning looking east from our vantage point

[Jbolin]

And this was 20 minutes later

[crf450ish]

[SilverFallsAndrew]

Smoke returned this morning. This week looks solidly wet. Pretty good signal for some ridging at the end of the month.

[DareDuck]

Sunriver, OR was the cold spot in the Lower 48 yesterday at 27 degrees.

 

Hard to believe after all the record heat earlier in the summer.

I can't wait to move down that way when I buy my own place. The weather there is so much more interesting than Bend. Their summer temps are more pleasant too.

[VancouverIslandSouth]

Looks like the smoke is back and will be here until the rain starts tomorrow afternoon per the smoke model.  

 

Also seems to be some agreement on a system Wednesday with heavy rain and some wind.    

 

Not so much as a hint of smoke here, seems like more of an onshore flow if anything.

[Phil]

Tropical storm Lee has formed, with Maria ready to form within about 12hrs. Maria is the bigger US threat.

[Front Ranger]

Euro keeps the ridging fairly weak. In fact, 850s never get above normal for the Puget Sound region through day 10.

[Phil]

September 11th, 1971. Seven simultaneous tropical cyclones.

 

Imagine the freak-out from today's climate alarmists if this happened again.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/61668609-C35C-4B83-9407-00955A24BCFF_zpsnoqkq9su.jpg

[Phil]

Regarding the pattern progression, watch the tropical forcing on the 12z ECMWF. By D5, this is pure wavenumber-1/Indo-China forcing, with a modest off-equator WHEM component.

 

This strengthens the east-Asian jet, favoring the downstream Aleutian anticyclone/-PNA and western US trough.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/9F2707D0-CBAF-437E-8897-68A815F59D7D_zpsq9x5sbjv.png

By D10, however, we see wavenumber-2/WHEM forcing developing, likely intraseasonal, but it still has time to increase the WHEM poleward latent heat fluxes and build ridging in western and central North America, which destructively interferes with the Aleutian ridge and allows the East-Asian jet to extend into the NPAC.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/681C0C20-4C4D-4E07-BEF1-81EA81A219A4_zps7vwxdanf.png

[Phil]

To close out September and begin October, all of the modeling weakens the Indo-China forcing, which makes sense, however the manner of the future progression shows large model to model inconsistency.

 

Given what we've observed over the last month or so, I'd lean towards the modeling that propagates the WHEM into the IO sometime during the middle of October.

[Jesse]

To close out September and begin October, all of the modeling weakens the Indo-China forcing, which makes sense, however the manner of the future progression shows large model to model inconsistency.

 

Given what we've observed over the last month or so, I'd lean towards the modeling that propagates the WHEM into the IO sometime during the middle of October.

This would mean?

[Phil]

This would mean?

It's debatable, but likely a gradual progression into something resembling a +EPO/GOA vortex and Canadian ridging over the next 2-3 weeks. There are potential wildcards, though, so keep your eyes peeled!

[Jesse]

It's debatable, but likely a gradual progression into something resembling a +EPO/GOA vortex and Canadian ridging over the next 2-3 weeks. There are potential wildcards, though, so keep your eyes peeled!

Sounds like another torchy October in the making.

[Phil]

Regardless of these intraseasonal fluctuations, the pattern over Eurasia is absolutely classic for -ENSO years that develop the Siberian High early.

 

This is good news for Jesse et al, because all -QBO/Niña years that were slow to develop the Siberian High ended up being dead ratters in the PNW.

 

It doesn't get better than this:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/E0334638-5BA9-40B5-BF24-92F35B0DF0D7_zpsuk7kku8n.png

[Phil]

Sounds like another torchy October in the making.

It looks more zonal than anything, in my opinion. At least across North America.

 

Different story on the other side of the globe. Going to be an absolute icebox over there.

[Phil]

Tropical storm Maria is officially born, joining tropical storm Lee and hurricane Jose. Maria could be especially important to the future evolution of the eastern North-American ridge, and a potential landfall threat.