September 2017 PNW Discussion Thread

[Jesse]

Honestly we are pretty overdue for a winter with a lot of cool, wet WNW flow.

[wx_statman]

The POAMA seasonal forecast (nailed last winter) is quite disappointing, unless you live in Alaska or maybe Tim's elevation.

 

Strongest +EPO in history?

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/7ABEF5B3-85FA-4E9F-8F82-ED562563FB38_zpsba6yxzng.jpg

 

A raging +EPO is always a risk with La Nina's here. Our two greatest 30-day +EPO stretches during DJF came during 1974-75 & 1998-99.

[TT-SEA]

A raging +EPO is always a risk with La Nina's here. Our two greatest 30-day +EPO stretches during DJF came during 1974-75 & 1998-99.

 

 

And we are WAY overdue for a very wet winter.  

[Phil]

A raging +EPO is always a risk with La Nina's here. Our two greatest 30-day +EPO stretches during DJF came during 1974-75 & 1998-99.

Yeah, especially in Niña/-QBO. Both of those years were -QBO.

 

For reference, 2011/12, 2007/08, 2005/06, 2001/02, and 1998/99 were all recent -QBO/-ENSO winters.

 

Meanwhile, 2016/17, 2013/14, 2010/11, and 2008/09 were all recent +QBO/-ENSO years. The NPAC blocking is much easier to come by during +QBO/-ENSO combos.

[Jesse]

Had a moderate shower here that lasted about 20 minutes. The steady rain still appears to be mostly offshore, though.

 

Sitting at 62 after a low of 52.

[TT-SEA]

Had a shower here that lasted about 20 minutes. The steady rain still appears to be mostly offshore, though.

 

The first band is going to be pretty pathetic... obviously the ramp up in onshore flow and cold air aloft is when we will see the heavy downpours.   The system on Wednesday morning dumps well over an inch for everyone south of Olympia.

[Jesse]

The first band is going to be pretty pathetic... obviously the ramp up in onshore flow and cold air aloft is when we will see the heavy downpours.   The system on Wednesday morning dumps well over an inch for everyone south of Olympia.

 

Tonight's front looks good for .25-.5". Not a deluge by any means, but the biggest single day rain total we have seen in nearly three months, by far. Pathetic.

[wx_statman]

Yeah, especially in Niña/-QBO. Both of those years were -QBO.

 

For reference, 2011/12, 2007/08, 2005/06, 2001/02, and 1998/99 were all recent -QBO/-ENSO winters.

 

Meanwhile, 2016/17, 2013/14, 2010/11, and 2008/09 were all recent +QBO/-ENSO years. The NPAC blocking is much easier to come by during +QBO/-ENSO combos.

 

It's a miracle that were were able to score a major Arctic outbreak in December 1998. That entire winter was dominated by onshore flow except for a single week in December. And we made the most of it. 

 

Looking at that list of -ENSO/-QBO combos really makes Dec 1998 stand out. 

[Jesse]

It's a miracle that were were able to score a major Arctic outbreak in December 1998. That entire winter was dominated by onshore flow except for a single week in December. And we made the most of it. 

 

Looking at that list of -ENSO/-QBO combos really makes Dec 1998 stand out. 

 

Mid-February 2006 had a decent blocking episode too. Then of course we have the December 2005 chilly period, but there was no upper level cold involved there really.

 

But yeah, those other winters were pretty onshore flow dominated.

[Phil]

During +AMOs, the QBO connection to PNW La Niña climate is uncannily strong. The correlation almost never breaks, except in rare cases like 1999/00 (failed +QBO/Niña), but even that required a perfect storm of discombobulated forcings to occur.

[wx_statman]

Another thing to watch for this winter is record cold in the Arctic. The -ENSO/-QBO combo allows cold air to build, and build, and build up there with the raging jet not providing any outlet southward. Months like January 2012 (coldest month on record in Bettles, AK), January 1999 (Finland national record low + major Alaskan cold wave with -74F in Chandalar Lake), and January 1975 (one of the greatest cold waves in AK & Yukon) are some good examples. 

[Phil]

Mid-February 2006 had a decent blocking episode too. Then of course we have the December 2005 chilly period, but there was no upper level cold involved there really.

 

But yeah, those other winters were pretty onshore flow dominated.

Yeah, also the fact 2005/06 was barely a Niña helped the blockiness somewhat, given the additional convection outside the Indo-China domain.

[wx_statman]

Mid-February 2006 had a decent blocking episode too. Then of course we have the December 2005 chilly period, but there was no upper level cold involved there really.

 

But yeah, those other winters were pretty onshore flow dominated.

 

February 2006 was a real fluke as well, that's for sure. 

 

Nothing really compares to December 1998 though. We've yet to match the -17.5c 850's from that cold wave, and it happened during one of the greatest +EPO winters on record. 1998-99 holds the modern (since 1948) +EPO records for 30 and 60 day periods, both coming after New Years. PDX didn't see a sub-32 reading until Dec 19th either, making 1998-99 possibly the greatest one-hit wonder in the modern era. 

[Phil]

Another thing to watch for this winter is record cold in the Arctic. The -ENSO/-QBO combo allows cold air to build, and build, and build up there with the raging jet not providing any outlet southward. Months like January 2012 (coldest month on record in Bettles, AK), January 1999 (Finland national record low + major Alaskan cold wave with -74F in Chandalar Lake), and January 1975 (one of the greatest cold waves in AK & Yukon) are some good examples.

Good point. The high latitudes have already cooled by several degrees relative to last year. A new NH July record low temperature was recorded in Greenland this year, as a matter of fact.

 

The -QBO also naturally invigorates topical convection (globally speaking) through a reduction in static stability, which cools the planet through increased tropics winds -> evaporative transport and increased cloud cover, however the +NAM/+NAO directly counters this, increasing the static stability integral.

[Front Ranger]

Yeah, especially in Niña/-QBO. Both of those years were -QBO.

 

For reference, 2011/12, 2007/08, 2005/06, 2001/02, and 1998/99 were all recent -QBO/-ENSO winters.

 

Meanwhile, 2016/17, 2013/14, 2010/11, and 2008/09 were all recent +QBO/-ENSO years. The NPAC blocking is much easier to come by during +QBO/-ENSO combos.

 

The biggest hope for this winter is that a quieter sun will allow more high latitude blocking. 2007-08 is the only winter in that list that was comparable from a solar extent.

[TT-SEA]

Going to be in Stevenson at Skamania Lodge next weekend... looks like we will have great weather.

 

Jesse - any ideas for activities and/or hikes?

[TT-SEA]

Good signal for warmth in the mid and long range on the 12Z EPS.

 

[Jesse]

Going to be in Stevenson at Skamania Lodge next weekend... looks like we will have great weather.

 

Jesse - any ideas for activities and/or hikes?

You can figure it out.

[TT-SEA]

You can figure it out.

 

Thanks!   

[wx_statman]

The biggest hope for this winter is that a quieter sun will allow more high latitude blocking. 2007-08 is the only winter in that list that was comparable from a solar extent.

 

There's also a question of Modoki vs. east-based. I've seen the 2007-08 Nina classified as Modoki before, based on the fact that Nino 4 anamolies were colder than Nino 3 during the mature phase (Jan-Mar 2008). I'm not sure what exactly our current Nina will end up as. 

[Anti Marine Layer]

Overcast thickening up gradually here.

Rain almost into Olympia now.

 

http://climate.cod.edu/data/nexrad/LGX/N0Q/LGX.N0Q.20170917.1844.gif

Not looking too impressive. Portland seems to be getting the tail end of it.

[Jesse]

Thanks!

A lot of places will be closed by fire damage.

[Phil]

The biggest hope for this winter is that a quieter sun will allow more high latitude blocking. 2007-08 is the only winter in that list that was comparable from a solar extent.

Yeah, but it's interesting that year also featured a persistent +NAM/+EPO. The closer I look at this, the more I'm seeing a negative feedback loop.

 

The -QBO always increases tropical convective ventilation and overall energy loss to space, but during -ENSO, the T/W feedbacks along the zero-wind line will tend to sustain the lower level PV/+NAM, which directly counters this ventilation.

 

In Niña/-QBO years with more ventilation potential, like 2007/08 and 2011/12, you'll almost always see the NAM run extremely positive, almost like the system is trying to avoid runaway phase locking and temperature drops.

 

The exact opposite is true in +ENSO with relation to the QBO and tropical ventilation.

[TT-SEA]

A lot of places will be closed by fire damage.

 

Ahhh... good to know.   On the WA side as well?

[VancouverIslandSouth]

Tonight's front looks good for .25-.5". Not a deluge by any means, but the biggest single day rain total we have seen in nearly three months, by far. Pathetic.

 

Looks pretty pathetic around here, the next 4 days give us maybe 0.2" then it's back to sunny/dry. I noticed one of our neighbour's large cedar scrubs has died, the tree must have been 30 or 40 years old. It's been through a lot but this 3 brutally dry warm seasons in a row was too much for it.

[wx_statman]

That seems a little uncalled for.

 

A lot of the places I would have recommended are closed due to the fire

 

Eh, you're kind of on a roll today between here and the California thread. 

 

I know for sure the Oregon side is a no-go. The WA side barely had any fire though. I would think areas up north of Carson/Stevenson would be fine. 

[TT-SEA]

Looks pretty pathetic around here, the next 4 days give us maybe 0.2" then it's back to sunny/dry. I noticed one of our neighbour's large cedar scrubs has died, the tree must have been 30 or 40 years old. It's been through a lot but this 3 brutally dry warm seasons in a row was too much for it.

 

Too bad they did not give it some water... build a little well and fill it up once a week.    But I guess hoses don't work up there based on what you tell us.  

[Geos]

Rain started about 15 minutes ago. Light so far.

[Jesse]

Eh, you're kind of on a roll today between here and the California thread.

 

I know for sure the Oregon side is a no-go. The WA side barely had any fire though. I would think areas up north of Carson/Stevenson would be fine.

 

I've never called you any names, so I would appreciate being treated with the same respect.

[Geos]

Notable SSTA differences between 9/16 and 9/17.

 

- La Niña stronger/more east-based this year.

- High latitudes much colder this year, snow/ice extent greater.

- South Pacific PDO (or "QDO") has flipped negative.

- IOD has reversed sign.

- PDO is actually more positive (for now).

 

2017 (top) vs 2016 (bottom):

 

 

 

Wow huge difference in the north Pacific south of the Aleutians!

[TT-SEA]

Rain started about 15 minutes ago. Light so far.

 

Very light.   Don't expect too much today.  

[Phil]

Back in the 1950s -ENSO period, this negative feedback loop began to fail, thanks to a period of excessive cooling in the tropical EHEM and a westward shifted Walker Cell.

 

This allowed the system to spiral into a -NAM/-PNA background state, which further reinforced the tropical ventilation, which further sustains the -NAM/-PNA through poleward dumping of heat/mass. This process continued through the 1950s and 1960s, and it wasn't until the mid-1970s that the tropical EHEM/WHEM thermal/SSTA gradient tightened enough to terminate the regime.

[wx_statman]

Pardon me? I made a dumb joke and got barked at by happ, and then asked how this trough would affect their weather down there. Dickhole move.

 

I've never called you any names, so I would appreciate being treated with the same respect.

 

Someone asked you about the place where you used to live, and you told them to "figure it out."

 

That's pretty rude. 

[wx_statman]

Back in the 1950s -ENSO period, this negative feedback loop began to fail, thanks to a period of excessive cooling in the tropical EHEM and a westward shifted Walker Cell.

 

This allowed the system to spiral into a -NAM/-PNA background state, which further reinforced the tropical ventilation, which further sustains the -NAM/-PNA through poleward dumping of heat/mass. This process continued through the 1950s and 1960s, and it wasn't until the mid-1970s that the tropical EHEM/WHEM thermal/SSTA gradient tightened enough to terminate the regime.

 

Fascinating stuff. 

[Phil]

Wow huge difference in the north Pacific south of the Aleutians!

Yeah, but IMO, what's even crazier is how the NPAC completely reversed within about 2 months last year.

 

Mother Nature hates dis-equilibrium, but sometimes she overcorrects.

 

 

[Jesse]

Someone asked you about the place where you used to live, and you told them to "figure it out."

 

That's pretty rude.

Most places I like in that area require a drive on gravel roads and a hike. I'm not sure what exactly I could recommend that Tim would be into.

 

I know that Skamania Lodge has a zip line course.

[TT-SEA]

Most places I like in that area require a drive on gravel roads and a hike. I'm not sure what exactly I could recommend that Tim would be into.

 

I know that Skamania Lodge has a zip line course.

 

My boys have been talking about the zip line course.  

 

We don't mind some challenging hikes.   One of my sons will mock us unless its very difficult.  

[VancouverIslandSouth]

Too bad they did not give it some water... build a little well and fill it up once a week.    But I guess hoses don't work up there based on what you tell us.  

 

Shouldn't have been necessary for larger mature trees like this. Trees are dying or going into drought-induced hibernation all over the place around town this year, you see it in many of the street trees downtown as well.

[TT-SEA]

Shouldn't have been necessary for larger mature trees like this. Trees are dying or going into drought-induced hibernation all over the place around town this year, you see it in many of the street trees downtown as well.

 

No... but nature can be cruel.   If you want to save your trees then you might have to help them out.   It does not take much.   Takes you 5 minutes a week and they are happy.   Or just let them die.   

[Phil]

Oh, and check out the reversal in the Pacific since April. These palpitations of the system state have been pretty crazy.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/41754FD1-1C21-4261-8EF6-47629C353053_zpsqal4ikaz.png