August 2017 PNW Discussion Thread

[Front Ranger]

Judging by the models I'm guessing this happens in about five days?

 

Yeah, I was curious too about how long the downstream feedbacks from the WPAC usually take to play out. Thought I've read 2-4 days, but can't remember for sure.

[TT-SEA]

When I reviewed low solar years in the late 19th and early 20th century locally, I was impressed by the seasonal extremes on both sides.

 

Lots of long, dry, warm summers and cold, snowy winters.    I was thinking it would have a been a great time to live here... maybe its happening again. 

[Jesse]

When I reviewed low solar years in the late 19th and early 20th century locally, I was impressed by the seasonal extremes on both sides.

 

Lots of long, dry, warm summers and cold, snowy winters. I was thinking it would have a been a great time to live here... maybe its happening again.

Lol.

[TT-SEA]

Lol.

 

Its true!  

 

1906-07 for example.    The summer of 1906 was awesome (by my standards which means the opposite of 1983 and 1993 type summers) and the winter of 1906-07 was also great.   Lots of snow and cold here... bottomed out with high of 18 and a low of 4 on 1/14/1907 with 18 inches of snow on the ground.  

 

The summer of 1908 was spectacular... and the winter of 1908-09 was cold and snowy.

 

The summer of 1909 was gorgeous... and 1909-10 was insanely cold and snowy here.

[Front Ranger]

When I reviewed low solar years in the late 19th and early 20th century locally, I was impressed by the seasonal extremes on both sides.

 

Lots of long, dry, warm summers and cold, snowy winters.    I was thinking it would have a been a great time to live here... maybe its happening again. 

 

It is pretty interesting that we're entering a period with lower level of solar activity than any point in the past century.

[TT-SEA]

It is pretty interesting that we're entering a period with lower level of solar activity than any point in the past century.

 

I can dream!  

 

Long, warm, dry summers and cold, snowy winters.   

[Kayla]

FWIW, playing around with autumn analogs, I keep getting a warm September, cold October, warm November type signal. Not exactly the most common progression, so I'm still tweaking things to see if it changes, but I find it interesting nonetheless.

 

AKA last year?

[Jesse]

AKA last year?

Last October was warm, and September was cool.

[Kayla]

Last October was warm, and September was cool.

 

Ahhh, right!

[Jesse]

Its true!

 

1906-07 for example. The summer of 1906 was awesome (by my standards which means the opposite of 1983 and 1993 type summers) and the winter of 1906-07 was also great. Lots of snow and cold here... bottomed out with high of 18 and a low of 4 on 1/14/1907 with 18 inches of snow on the ground.

 

The summer of 1908 was spectacular... and the winter of 1908-09 was cold and snowy.

 

The summer of 1909 was gorgeous... and 1909-10 was insanely cold and snowy here.

Would need to see more than one outlier-esque cold winter (which didn't even feature a true arctic outbreak in the end) to start even considering this could maybe possibly be a trend. The true trend over recent decades has been hotter summers and warmer, wetter winters. Consistent with a warming regional climate/ globe on the whole.

[Jesse]

They actually spiked to 99 just before 5pm which surpasses 8/31/1998.

Probably a rounding error. 98.

[Front Ranger]

Would need to see more than one outlier-esque cold winter (which didn't even feature a true arctic outbreak in the end) to start even considering this could maybe possibly be a trend. The true trend over recent decades has been hotter summers and warmer, wetter winters. Consistent with a warming regional climate/ globe on the whole.

 

There is plenty of evidence that lower solar activity is correlated with increased NH blocking, though. Most recently, 2008-11 was the lowest 4 year period of solar activity since the 1910s. It was also a very blocky period for the NH, and featured 4 major Arctic outbreaks in 3 winters for the PNW.

 

Point being, I do think lower solar activity is your best bet for enjoyable winter weather at this point. Summer...harder to say.

[Deweydog]

They actually spiked to 99 just before 5pm which surpasses 8/31/1998.

Nice call.

[Phil]

Would need to see more than one outlier-esque cold winter (which didn't even feature a true arctic outbreak in the end) to start even considering this could maybe possibly be a trend. The true trend over recent decades has been hotter summers and warmer, wetter winters. Consistent with a warming regional climate/ globe on the whole.

I'd argue it's a lot more complicated than simply warmer global temperatures. There are a number of factors that have pushed the system into a more +PNA/+NAM winter circulation in recent decades, and most of this would have occurred independent of any change(s) to the global temperature beforehand.

[TT-SEA]

Would need to see more than one outlier-esque cold winter (which didn't even feature a true arctic outbreak in the end) to start even considering this could maybe possibly be a trend. The true trend over recent decades has been hotter summers and warmer, wetter winters. Consistent with a warming regional climate/ globe on the whole.

 

Very true.  

 

I am sure its just wishful thinking on my part... after the extended period of cold and snowy here last December and January with so many sunny days with snow on the ground... followed by an incredible long, dry, sunny summer.   I am intentionally ignoring the mess that was spring in between.  

[Jesse]

Nice call.

They only hit 98. You were actually right!

 

#slowlyrecoveringfromshamefulaugusticeboxprediction

[Phil]

This isn't a result of warmer temperatures. It's a result of changes to zonal/meridional tropical Pacific SST gradients. The climate system is full of various responsive fluid resonances.

 

(Note the positive trend in the (J/F/M) PNA/NAO):

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/B19F7D94-266D-41A6-A881-384F2D46A082_zpsliwn3gpb.png

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/6A5917A9-4C67-4718-86EE-5331069068C7_zpsfkijfvnm.png

[Jesse]

There is plenty of evidence that lower solar activity is correlated with increased NH blocking, though. Most recently, 2008-11 was the lowest 4 year period of solar activity since the 1910s. It was also a very blocky period for the NH, and featured 4 major Arctic outbreaks in 3 winters for the PNW.

 

Point being, I do think lower solar activity is your best bet for enjoyable winter weather at this point. Summer...harder to say.

Enjoyable to who I guess is the question. 2008, 2010 and 2011 were some of the most enjoyable summers of recent years IMO.

[Deweydog]

They only hit 98. You were actually right!

 

#slowlyrecoveringfromshamefulaugusticeboxprediction

Bad call!

 

#septemberwillsaveme

[Kayla]

Nice call.

 

You should get a Nick Lachey tattoo!

[Front Ranger]

Enjoyable to who I guess is the question. 2008, 2010 and 2011 were some of the most enjoyable summers of recent years IMO.

 

Yeah, summer is obviously more debatable. 

 

But everyone here can appreciate more blocking and increased odds of cold, snowy winters.

[Front Ranger]

You should get a Nick Lachey tattoo!

 

Speaking of blasts from the past!

[Phil]

00z NAM drops another 20-35"+ of rain in SE Texas, in areas that have already received 30"+. Unbelievable.

[Phil]

I can't watch the Houston radar anymore. It's nauseating.

 

The US tropical cyclone rainfall record will easily be broken by morning, and another 10-20"+ will fall afterwards as moisture fluxes increase off the Gulf again.

[TT-SEA]

Yeah, summer is obviously more debatable. 

 

But everyone here can appreciate more blocking and increased odds of cold, snowy winters.

 

You must mean debatable on this forum.

 

I would argue that most people would like long, dry, sunny summers (with no extreme heat) and least amount of lowland snow possible.   

[Front Ranger]

You must mean debatable on this forum.

 

I would argue that most people would like long, dry, sunny summers (with no extreme heat) and least amount of lowland snow possible.   

 

This forum is all that matters for this forum.

[TT-SEA]

I can't watch the Houston radar anymore. It's nauseating.

 

The US tropical cyclone rainfall record will easily be broken by morning, and another 10-20"+ will fall afterwards as moisture fluxes increase off the Gulf again.

 

I am watching the drier air to the west which seems to be inching towards the Houston area... the center seems to be moving a little farther offshore as well.  

 

I think tomorrow will be a much better day with just light rain and a north wind.

[wx_statman]

Nice to see the 98 verify today, after yesterday's 95. Very impressive for 8/28 in its own right, regardless of what happens next week.

[Front Ranger]

I can't watch the Houston radar anymore. It's nauseating.

 

The US tropical cyclone rainfall record will easily be broken by morning, and another 10-20"+ will fall afterwards as moisture fluxes increase off the Gulf again.

 

Actually looks to be improving. Rain shield is now confined mainly to coastal areas. Worst case scenario would have the heavy rain much further inland, west and north of Houston.

[TT-SEA]

This forum is all that matters for this forum.

 

Gotcha... the 12 of us are all that matters.   I totally agree.    

[Front Ranger]

Nice to see the 98 verify today, after yesterday's 95. Very impressive for 8/28 in its own right, regardless of what happens next week.

 

Today was no 1967, though...

[Phil]

I am watching the drier air to the west which seems to be inching towards the Houston area... the center seems to be moving a little farther offshore as well.

 

I think tomorrow will be a much better day with just light rain and a north wind.

I guess that depends on what your definition of "better" is. With Harvey's center now back over the Gulf, I'd expect upward moisture fluxes to increase, albeit a bit farther S/E.

 

Given over 40" has already fallen, another 10-20" would be absolutely catastrophic. Even another 6" would worsen the situation exponentially.

[wx_statman]

Its true!  

 

1906-07 for example.    The summer of 1906 was awesome (by my standards which means the opposite of 1983 and 1993 type summers) and the winter of 1906-07 was also great.   Lots of snow and cold here... bottomed out with high of 18 and a low of 4 on 1/14/1907 with 18 inches of snow on the ground.  

 

The summer of 1908 was spectacular... and the winter of 1908-09 was cold and snowy.

 

The summer of 1909 was gorgeous... and 1909-10 was insanely cold and snowy here.

 

Summers were cooler in that era. Salem managed just 4 days at 90+ in 1909, 3 in 1910...

[wx_statman]

Today was no 1967, though...

 

A lot less hippies, for sure.

[Phil]

Total rainfall so far through 8/27. Many of the hardest hit areas are still getting dumped on, and this will only continue as center of convergence moves N/NE later tonight.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/B21BFFE8-EFA5-4F50-9E6A-638466426D92_zpsze3fjh38.png

[Front Ranger]

I guess that depends on what your definition of "better" is. With Harvey's center now back over the Gulf, I'd expect upward moisture fluxes to increase, albeit a bit farther S/E.

 

Given over 40" has already fallen, another 10-20" would be absolutely catastrophic. Even another 6" would worsen the situation exponentially.

 

All depends on how fast it fell and where. If Houston sees another 5-10" over the next 24 hours, but drainage areas west and north of the city see way less, it probably won't worsen the situation much at all.

[Phil]

All depends on how fast it fell and where. If Houston sees another 5-10" over the next 24 hours, but drainage areas west and north of the city see way less, it probably won't worsen the situation much at all.

Houston sits in a virtual bowl with an opening to the SE. Any rain that falls in and around the city (except for the SE corridor) will worsen the situation. Areas E/NE of the city also drain SW-ward, into the metro area and surroundings.

 

Areas to the S/SW also drain into the city.

[TT-SEA]

Total rainfall so far through 8/27. Many of the hardest hit areas are still getting dumped on, and this will only continue as center of convergence moves N/NE later tonight.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/B21BFFE8-EFA5-4F50-9E6A-638466426D92_zpsze3fjh38.png

 

Amazing how the center of the heaviest rain is right over the Houston metro area.    Record rainfall in a place for maximum impact.

[Front Ranger]

Houston sits in a virtual bowl with an opening to the SE. Any rain that falls in and around the city (except for the SE corridor) will worsen the situation. Areas E/NE of the city also drain SW-ward, into the metro area and surroundings.

 

From what I understand, the largest watersheds into the metro area are to the W/NW. Couple of large dams there that were close to having spillage. Rain to the NE is not good, but as long as it doesn't fall too fast, the drainage system they have in place will function at roughly the same level it's functioning now - at least that's what I've heard from those living in the area.

[Phil]

From what I understand, the largest watersheds into the metro area are from the N/NW. Couple of large dams there that were close to having spillage. Rain to the NE is not good, but as long as it doesn't fall too fast, the drainage system they have in place will function at roughly the same level it's functioning now - at least that's what I've heard from those living in the area.

I think that's a fair assessment, however, much of that water drains into reservoirs and rivers that are already at/near capacity after 40"+ of rainfall.

 

There are also at least two watershed tributaries to the S/SW of the city, draining N/NE-ward. So I'm not optimistic, but I would love to be proven wrong here. Especially with the center of convergence poised to move north again later tonight or tomorrow, I don't like the look of this situation over the next 24hrs.