September 2017 PNW Discussion Thread

[TT-SEA]

68/51 at SEA today... perfectly normal.    

 

Clouds are holding up temps at night. 

[Jesse]

68/51 at SEA today... perfectly normal.    

 

Clouds are holding up temps at night.

 

PDX was -6 today.

[wx_statman]

Sorry then. I really don't want any beef with you. I misunderstood the post. You were talking about other places going from highs in the low 50s to low 40s the next day and I thought maybe that's what you meant. It was an interesting event I hadn't heard about before, so I was trying to make sure I understood what you were saying.

 

All right, fair enough. Sorry if I was being kind of a d*ck. 

[ShawniganLake]

68/51 at SEA today... perfectly normal.

 

Clouds are holding up temps at night.

68/46 here today. That's roughly a -1F.

[Front Ranger]

68/51 at SEA today... perfectly normal.    

 

Clouds are holding up temps at night. 

 

No shocker here, but SEA has run warmer than just about anywhere else with this trough. Couldn't even manage one low in the 40s.

[stuffradio]

The 00Z ensembles have warmed slightly, but the main run and the control of the GFS both show similar amounts of rain, and the control actually has more than the main run at one point. There are still some members below 0C 850mb in the long range though.

 

[BLI snowman]

October 6-8, 1949 was interesting as well. Battle Ground had a 51 degree high on the 7th, followed by 32 on the 8th. There was measurable rain on both days although the overnight hours were dry. Cedar Lake at 1,560' was 45/37 with a trace of snow on the 6th. Nice little precursor to the much more impressive airmass 10 days later. 

 

 

Which also produced some very light snow apparently in NW WA with the arctic front on 10/17-10/18. Olga had a trace.

 

Getting cold like that in a non-Nino October is always a great sign.

[wx_statman]

Which also produced some very light snow apparently in NW WA with the arctic front on 10/17-10/18. Olga had a trace.

 

Getting cold like that in a non-Nino October is always a great sign.

 

Very impressive, but not surprising given that airmass. That was probably the earliest true Fraser blast at least in modern records.

 

Something similar happened on October 17, 1905. Arctic front through the Puget Sound with northerlies up to 47 mph, according to the monthly state climo report. Brinnon had a trace of snow along with a 46/28 day. 

[wx_statman]

FWIW, my vote for most impressive early season large snowstorm was the 22" that fell at Duckabush on the Hood Canal from November 10-12, 1911. 

[ShawniganLake]

FWIW, my vote for most impressive early season large snowstorm was the 22" that fell at Duckabush on the Hood Canal from November 10-12, 1911.

Oct 31-Nov 1, 1984. 8-20" along east Vancouver island. 18" at Campbell river. 20" at Nanaimo A.

[wx_statman]

Oct 31-Nov 1, 1984. 8-20" along east Vancouver island. 18" at Campbell river. 20" at Nanaimo A.

 

Nice. If we're including Canada then yeah 1984 probably takes the crown here. Hope received 30" between October 28 - November 2, with 19" on the 1st. 

[wx_statman]

I also like November 8-9, 1945 in the Fraser Valley. 18" at Chilliwack. 

[Kayla]

Nah. If the warm runs verify, you might be looking at three 85/50-ish days to close the month. That wouldn't be enough to push up the monthly average hardly at all, which will be below the record within a couple days.

 

Monthly departure for PDX is down to +2.6.

 

Yet still coming out of the cold trough with a +0.3 on the record.

 

It's all gonna come down to those positive departures Tuesday - Saturday! Still feeling pretty good about my "sensationalistic call". 

[Jesse]

Yet still coming out of the cold trough with a +0.3 on the record.

 

It's all gonna come down to those positive departures Tuesday - Saturday! Still feeling pretty good about my "sensationalistic call".

To be fair the next three days will only have highs on either side of 70, though. Which will continue to drag things down. We'll be below the record by tomorrow.

 

It will come down to whether we stay warm on the 29th/30th or get some sort of cooldown back into the low-mid 70s. Unexpectedly mild nights the rest of the way through could also destroy Flatiron's dreams.

[Kayla]

To be fair the next three days will only have highs on either side of 70, though. Which will continue to drag things down. We'll be below the record by tomorrow.

 

It will come down to whether we stay warm on the 29th/30th or get some sort of cooldown back into the low-mid 70s. Unexpectedly mild nights the rest of the way through could also destroy Flatiron's dreams.

 

Yeah no doubt the next 3 days will drop it below the record but the question is whether it's gonna be enough to overcome the positive departures on the last 4 days of the month to keep it just shy of the record.

 

As I've been saying for a while now, it's gonna be close!

[Jesse]

Yeah no doubt the next 3 days will drop it below the record but the question is whether it's gonna be enough to overcome the positive departures on the last 4 days of the month to keep it just shy of the record.

 

As I've been saying for a while now, it's gonna be close!

I think everyone's been saying that.

[Kayla]

I think everyone's been saying that.

 

Except Jared who has vigorously held steadfast with reasons why it will not happen all month! 

[Jesse]

Except Jared who has vigorously held steadfast with reasons why it will not happen all month!

#-pdosaiditwouldnthappen

[TT-SEA]

Clouds held up the temps around Seattle last night and now its sunny this morning. Only 55 at SEA for a low.

[Jesse]

Clouds held up the temps around Seattle last night and now its sunny this morning. Only 55 at SEA for a low.

I couldn't remember. Are you spending the weekend at Skamania Lodge or Sea-Tac?

[TT-SEA]

I couldn't remember. Are you spending the weekend at Skamania Lodge or Sea-Tac?

 

 

I am never at SEA even when I am home.   But I still track what is happening there.   The internet is pretty cool.  

[Jesse]

I am never at SEA even when I am home. But I still track what is happening there. The internet is pretty cool.

I figured we'd be getting more weather reports from Stevenson. How is it out there?

[TT-SEA]

I figured we'd be getting more weather reports from Stevenson. How is it out there?

 

Still cloudy.   Satellite shows it should clear up fairly soon though.  

[Phil]

I suspect we'll be seeing lots of patterns like this over the next several months. Classic Niña/-QBO, with the -PNA/+EPO.

 

#2007/08

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/27C2F08A-CC2B-4F1D-ABAE-ECA6135607B7_zpsrj9hwgoy.png

[TT-SEA]

I suspect we'll be seeing lots of patterns like this over the next several months. Classic Niña/-QBO, with the -PNA/+EPO.

 

#2007/08

 

 

 

Yeah... that is not a great pattern for lowland snow.   But a pattern that can bury Andrew and sometimes even my area in snow with cold onshore flow.

[Phil]

Yeah... that is not a great pattern for lowland snow. But a pattern that can bury Andrew and sometimes even my area in snow with cold onshore flow.

Also, as Demitri alluded to, the -PNA/Aleutian Ridge restricts heat transport into the Arctic, cooling most of the high latitudes over a period of several months.

 

So, if the Arctic is actually released at some point this winter, unlike 2007/08, then it could be interesting for someone. These Niña/-QBO winters don't always stay +EPO. We'd need to find a way to dislodge the polar vortex, though.

[TT-SEA]

Also, as Demitri alluded to, the -PNA/Aleutian Ridge restricts heat transport into the Arctic, cooling most of the high latitudes over a period of several months.

 

So, if the Arctic is actually released at some point this winter, unlike 2007/08, then it could be interesting for someone. These Niña/-QBO winters don't always stay +EPO. We'd need to find a way to dislodge the polar vortex, though.

 

Is there a planning meeting scheduled?   We need to develop the plan to dislodge the polar vortex.   Needs to be a team effort though!  

[Front Ranger]

Except Jared who has vigorously held steadfast with reasons why it will not happen all month!

Odds have been against it all month, and that continues.

[Phil]

Is there a planning meeting scheduled? We need to develop the plan to dislodge the polar vortex. Needs to be a team effort though!

It's already discussing terms of surrender with Mt. Agung and the WPAC Hadley Cell. No announcement date, as of yet.

[weatherfan2012]

Also, as Demitri alluded to, the -PNA/Aleutian Ridge restricts heat transport into the Arctic, cooling most of the high latitudes over a period of several months.

So, if the Arctic is actually released at some point this winter, unlike 2007/08, then it could be interesting for someone. These Niña/-QBO winters don't always stay +EPO. We'd need to find a way to dislodge the polar vortex, though.

in the long run this could be a good thing as it could set up coast to coast harsh winters over the next few years those let's hope to it not to much of a good thing those .if we have a big volcano eruption or two doing a very low grand solar minimum with cycles 25 and 26 that could be big trouble and is one of the ways glacier cycles in the ice age cycle could begin.one of the things and rightly so that Robert Filex is concerned about.

[Phil]

Depressing autumn for me, though, considering the history of failure here in Niña/-QBO winters.

 

These dogs usually dominate us with dry southerlies, intermixed with warm rain squalls, ice storms, and westerly ragers that coincide with trash night and pulverize our screens and shutters.

[Jesse]

Odds have been against it all month, and that continues.

12z GFS MOS has 55+ lows the rest of the month after tomorrow morning, with highs in the 80s the last four days of the month. That would definitely seal the deal.

[stuffradio]

in the long run this could be a good thing as it could set up coast to coast harsh winters over the next few years those let's hope to it not to much of a good thing those .if we have a big volcano eruption or two doing a very low grand solar minimum with cycles 25 and 26 that could be big trouble and is one of the ways glacier cycles in the ice age cycle could begin.one of the things and rightly so that Robert Filex is concerned about.

Mount Agung is no Yellowstone, so I don't think there is any need to worry about a glacial period.

 

The 12Z Operational drops 850 levels to just below 0C before hour 300!

[epiceast]

Mount Agung is no Yellowstone, so I don't think there is any need to worry about a glacial period.

 

The 12Z Operational drops 850 levels to just below 0C before hour 300!

 

Is it a Pinatubo though? Just trying to get some cold anomaly that we don't have to pay back for later with a warm anomaly!

[Phil]

in the long run this could be a good thing as it could set up coast to coast harsh winters over the next few years those let's hope to it not to much of a good thing those .if we have a big volcano eruption or two doing a very low grand solar minimum with cycles 25 and 26 that could be big trouble and is one of the ways glacier cycles in the ice age cycle could begin.one of the things and rightly so that Robert Filex is concerned about.

What's good (well, technically it's bad) in the long run is the drawdown of the NH meridional modes, and prospects of a grand solar minimum, which will alter climate through changes in large scale circulation and mass balance.

 

Glacial inception, however, requires an established seasonal bipolar seesaw, which we're pretty far away from achieving right now. In other words, the winter hemisphere experiences a permanently negative annular mode (polar high), while the summer hemisphere experiences a positive annular mode (polar low). This occurs as obliquity declines, increasing topical insolation at the expense of polar insolation, which gradually tightens the equator/pole thermal gradient in the atmosphere and oceans (warm tropics/cool poles), strengthening topical convection and wind speeds. This increases cloud albedo and thermo-mechanically ventilates heat from the tropical oceans, as higher wind speeds enhance evaporative cooling at the sea surface, which said latent heat is then subsequently released in the mid/upper troposphere in the vigorous convection, hence is more easily emitted to space.

 

This process also dumps a bunch of excess heat/mass into the polar domians, where the heat can be more effectively radiated thanks the lack of insolation/seasonal energy deficit, as well as the enhanced sinking/adiabatic warming produced by the heat/mass dumpage (negative annular mode), which inhibits polar cloud formation, further enhancing the radiative loss.

 

The winter hemisphere, away from the ITCZ, experiencess the negative annular mode because the tightened insolation gradient over that hemisphere produces a more spatially coupled, lower frequency wave system, through both thermodynamic and photochemical processes, which enhances the coupling and exchange(s) between the tropics, pole, and stratosphere. Meanwhile, the summer hemisphere, closer to the ITCZ, experiences the positive annular mode because the lessened insolation gradient, through the same processes, produces a less spatially coupled, higher frequency wave system, which breaks the direct equator/pole exchanges, such that the excess heat/mass ventilated from the tropics is dumped in the subtropics/mid-latitudes, rather than over the high latitudes.

 

In other words, picture a vertically-tall, but latitudinally-skinny convective cell network in the summer hemisphere, and a vertically-challenged, but latitudinally-broad convective cell network in the winter hemisphere. This isn't the truly correct way to describe it, but it serves our purposes here.

 

In regards to the current climate system state, while obliquity is technically low enough to produce the aforementioned seasonal bipolar seesaw (as evidenced by MIS19c), and the thermal gradient is tight by standards of the last 8,000yrs, the ocean/atmosphere system itself hasn't yet crossed the thermodynamic threshold that would allow for a descent into this state of operation. A prolonged grand solar minimum under our current orbital conditions could theoretically be enough to push the system over the threshold, however, as of today, we have yet to actually enter the grand minimum, and we need to see this positive trend in the annular modes reverse before we can even begin to talk about a bipolar seesaw and glacial inception. As of today, we remain in a system state composed of a positive planetary annular mode.

[weatherfan2012]

What's good (well, technically it's bad) in the long run is the drawdown of the NH meridional modes, and prospects of a grand solar minimum, which will alter climate through changes in large scale circulation and mass balance.

Glacial inception, however, requires an established seasonal bipolar seesaw, which we're pretty far away from achieving right now. In other words, the winter hemisphere experiences a permanently negative annular mode (polar high), while the summer hemisphere experiences a positive annular mode (polar low). This occurs as obliquity declines, increasing topical insolation at the expense of polar insolation, which gradually tightens the equator/pole thermal gradient in the atmosphere and oceans (warm tropics/cool poles), strengthening topical convection and wind speeds. This increases cloud albedo and thermo-mechanically ventilates heat from the tropical oceans, as higher wind speeds enhance evaporative cooling at the sea surface, which said latent heat is then subsequently released in the mid/upper troposphere in the vigorous convection, hence is more easily emitted to space.

This process also dumps a bunch of excess heat/mass into the polar domians, where the heat can be more effectively radiated thanks the lack of insolation/seasonal energy deficit, as well as the enhanced sinking/adiabatic warming produced by the heat/mass dumpage (negative annular mode), which inhibits polar cloud formation, further enhancing the radiative loss.

The winter hemisphere, away from the ITCZ, experiencess the negative annular mode because the tightened insolation gradient over that hemisphere produces a more spatially coupled, lower frequency wave system, through both thermodynamic and photochemical processes, which enhances the coupling and exchange(s) between the tropics, pole, and stratosphere. Meanwhile, the summer hemisphere, closer to the ITCZ, experiences the positive annular mode because the lessened insolation gradient, through the same processes, produces a less spatially coupled, higher frequency wave system, which breaks the direct equator/pole exchanges, such that the excess heat/mass ventilated from the tropics is dumped in the subtropics/mid-latitudes, rather than over the high latitudes.

In other words, picture a vertically-tall, but latitudinally-skinny convective cell network in the summer hemisphere, and a vertically-challenged, but latitudinally-broad convective cell network in the winter hemisphere. This isn't the truly correct way to describe it, but it serves our purposes here.

In regards to the current climate system state, while obliquity is technically low enough to produce the aforementioned seasonal bipolar seesaw (as evidenced by MIS19c), and the thermal gradient is tight by standards of the last 8,000yrs, the ocean/atmosphere system itself hasn't yet crossed the thermodynamic threshold that would allow for a descent into this state of operation. A prolonged grand solar minimum under our current orbital conditions could theoretically be enough to push the system over the threshold, however, as of today, we have yet to actually enter the grand minimum, and we need to see this positive trend in the annular modes reverse before we can even begin to talk about a bipolar seesaw and glacial inception. As of today, we remain in a system state composed of a positive planetary annular mode.

yeah interesting to add that Jim Bob that posts on Roberts blog has express a few times that he be leaves we sill have 3 more solar 160 year warm phases to contend with but each one cycle would be less warm then the one before it.so he targeting thousand years or so away yet interesting but another possable idea.

[Front Ranger]

12z GFS MOS has 55+ lows the rest of the month after tomorrow morning, with highs in the 80s the last four days of the month. That would definitely seal the deal.

 

Possible. Not likely.

 

85/57 days are very rare in late September.

[TT-SEA]

Bridge of the Gods... between WA and OR.    Gorgeous day!

 

[Front Ranger]

EPS and GFS ensembles both point towards troughing returning by the first week of October.

[TT-SEA]

EPS and GFS ensembles both point towards troughing returning by the first week of October.

I called it with my adjustment on Phil's forecast.