August 2023 Weather in the PNW

[TT-SEA]

Just now, Deweydog said:

July 1 was sunny at the coast. I was there and it was divine.

Sorry, Sounders. If I could have bottled it and sent it your way I would!

We had to suffer through a 20% cloudy day but never actually saw a cloud.  

[Phil]

7 minutes ago, TT-SEA said:

And parts of the rust belt.   Pittsburgh averages 2,030 sunshine hours per year while Seattle averages 2,170.   

And that was my point yesterday.   We are one of the cloudiest places in the US... but most of Europe has less than sun than Seattle.   Our reputation stems from an our position in our own country... not across the world.  

FWIW the 1991-2020 average at KPIT is 2378hrs annually, or roughly 54% of possible sunshine hours.

KSEA annual average is 48% of possible sunshine hours. In other words, the sun is shining ~ 25% of the year in Seattle.

[TT-SEA]

2 minutes ago, Phil said:

FWIW the 1991-2020 average at KPIT is 2378hrs annually, or roughly 54% of possible sunshine hours.

KSEA annual average is 48% of possible sunshine hours.

I would venture to guess that Seattle's average is going up... since the marine layer has become less of a feature in the summer over the last decade.  

[AmunRAEL]

[Phil]

Just now, TT-SEA said:

I would venture to guess that Seattle average is going up as well... since the marine layer has become less of a feature in the summer over the last decade.  

I only have the 1991-2020 average. But KSEA does have the the highest cloud cover fraction of all major US cities.

Interestingly the Great Lakes region (including KPIT) has seen a decrease in the average annual cloud cover fraction, but that is all focused in the fall/winter months.

[TT-SEA]

12Z EPS... would like to see the 90s disappear.   It is pretty unusual for the EPS to show temps that anomalous in the far long range when it usually drifts to climo.   

[TigerWoodsLibido]

3 hours ago, Phishy Wx said:

early fall means death bow to winter most likely

Sometimes. Recency bias has definitely felt like a trend for sure. Going back to that 2002-03 October cold snap.

[TT-SEA]

1 minute ago, Phil said:

I only have the 1991-2020 average. But KSEA does have the the highest cloud cover fraction of all major US cities.

Interestingly the Great Lakes region (including KPIT) has seen a decrease in the average annual cloud cover fraction, but that is all focused in the fall/winter months.

Not sure... because up until last winter the rainy season has been getting wetter so it might offset the warmer/sunnier summers in the annual stats.  

But there is no doubt our summers have become warmer and sunnier.  

[TigerWoodsLibido]

19 minutes ago, Slushy Inch said:

What do you guys think about the talk about that ocean current possibly turning off and potentially resulting in some cooling? Especially in Europe.

Been intrigued by the gulf stream slowing down for a while. Wondering if it'll have an effect on buckling the PV more?

[Phil]

3 minutes ago, TT-SEA said:

12Z EPS... would like to see the 90s disappear.   It is pretty unusual for the EPS to show temps that anomalous in the far long range when it usually drifts to climo.   

Will likely be 2-3 days 90+ then crash.

LR ensemble means always have broad windows for the largest anomalies, whether warm or cold.

[TT-SEA]

8 minutes ago, ChristheElohim said:

I am going to go ahead and call this yet another cloudy Seattle day... because I bet I can see those clouds off in the distance if I look for them.   

[Deweydog]

1 minute ago, Phil said:

Will likely be 2-3 days 90+ then crash.

LR ensemble means always have broad windows for the largest anomalies, whether warm or cold.

It’s exceedingly rare for Seattle to see more than three 90+ degree days in a row.

[TT-SEA]

1 minute ago, Phil said:

Will likely be 2-3 days 90+ then crash.

LR ensemble means always have broad windows for the largest anomalies, whether warm or cold.

Only 2 days above 90 at SEA so far this year so that could more than double the total.     SEA averages 3 days at or above 90 per year.    I would love to finish the summer with 2 days and a peak of 91 where it currently stands.   Something special about an endlessly sunny, warm summer with almost no heat.  

[Phishy Wx]

52 minutes ago, Snownerd3000 said:

 

so GFS is garbage.  He already knew that

[TigerWoodsLibido]

BAM! 90F

[Phil]

1 minute ago, TT-SEA said:

Not sure... because up until last winter the rainy season has been getting wetter so it might offset the warmer/sunnier summers in the annual stats.  

But there is no doubt our summers have become warmer and sunnier.  

Well, they have trended warmer/sunnier for the last couple decades, at least. But that’s still a pretty short reference period (w/rt scale of “climate”). If we had solid pre-WWII data that average would be more reflective (previous +PMM/warm phase would be included).

[Phil]

9 minutes ago, Deweydog said:

It’s exceedingly rare for Seattle to see more than three 90+ degree days in a row.

What about upper 80s? I’ll leave the exact magnitudes up to you guys.

Point is, the duration is probably overdone to some degree, based on the nature of LR ensemble means.

[TT-SEA]

Just now, Phil said:

Well, they have trended warmer/sunnier for the last couple decades, at least. But that’s still a pretty short reference period (w/rt scale of “climate”). If we had solid pre-WWII data that average would be more reflective (previous +PMM/warm phase would be included).

Yeah... definitely a short reference period.   But it seems like its here to stay for awhile.   Triple Nina and every summer was warm and dry... now a developing Nino and its warm and dry.    Seems to be the default and likely related to overall global warming.    But who knows... that is above my pay grade.    I know it won't last forever.  

[Phil]

8 minutes ago, TT-SEA said:

Yeah... definitely a short reference period.   But it seems like it’s here to stay for awhile.   Triple Nina and every summer was warm and dry... now a developing Nino and it’s warm and dry.    Seems to be the default and likely related to overall global warming.    But who knows... that is above my pay grade.    I know it won't last forever.  

The interdecadal scale is dominated by internal variability at the regional level. See the Plains/SE US, where summers have trended cooler/wetter post-WWII.

Summers over the next 20 years could easily shift cooler/wetter in the PNW regardless of the degree of global climate warming. Comes down to changes in low frequency atmospheric circulation (which is surprisingly fickle…can remain stable for decades then boom, it reshuffles in the blink of an eye).

[Snownerd3000]

13 minutes ago, Phishy Wx said:

so GFS is garbage.  He already knew that

Wrong detail to focus on. I thought it was awesome to see a single gpu and ai competing with a super computer. The future is now.

[Front Ranger]

Euro looks ugly at the end. At least there's no model consensus yet for that sort of death ridge developing, but certainly looks plausible given pattern evolution.

[Cold Snap]

Had an 81/49 spread yesterday. Currently at an 82/50 spread so far today.

[BLI snowman]

1 hour ago, TT-SEA said:

How about a picture from 1 a.m. that day... mid level clouds drifted through in the early morning hours.   So it was technically cloudy for 20% of the day.    But yet it was totally sunny from dawn to dusk.    Stats don't tell the whole story.   

 

Little did those clouds know they would soon be among the most controversial in Seattle history.

[TT-SEA]

37 minutes ago, Phil said:

FWIW the 1991-2020 average at KPIT is 2378hrs annually, or roughly 54% of possible sunshine hours.

KSEA annual average is 48% of possible sunshine hours. In other words, the sun is shining ~ 25% of the year in Seattle.

This is wrong.   The sun is not shining just 25% of the year in Seattle.   It's just not accurate.   My guestimate is that the sun is shining 45-50% of the time in Seattle.  More specifically... probably around 75% in the summer and 25% in the winter and somewhere in between in the spring and fall. 

[Phil]

2 minutes ago, Front Ranger said:

Euro looks ugly at the end. At least there's no model consensus yet for that sort of death ridge developing, but certainly looks plausible given pattern evolution.

Interestingly the LP in VP200 is more phase-8 than phase-7, which usually suggests the opposite type of pattern (troughs at the coasts, ridge in the middle) compared to the EPS projection. Perhaps WPAC typhoons/DHR, CCKWs, etc are a factor here.

Still, wouldn’t be shocked if guidance made a significant move sometime in the next week. Precisely the type of situation where you’d expect that to happen.

[Phil]

6 minutes ago, TT-SEA said:

This is wrong.   The sun is not shining just 25% of the year in Seattle.   It's just not accurate.   My guestimate is that the sun is shining 45-50% of the time in Seattle.  More specifically... probably around 75% in the summer and 25% in the winter and somewhere in between in the spring and fall. 

A DAY IS 24 HOURS. Goodness gracious.

50% of the time would be 100% of possible sunshine hours.

[TT-SEA]

Just now, Phil said:

A DAY IS 24 HOURS.

Goodness gracious.

Sunshine is not possible at night! 

48% of possible sunshine hours means 48% of daylight hours.   That is a more meaningful way to look at it.   

I am well aware that we lose 50% of the year right off the bat because it's nighttime.   

[Phil]

Just now, TT-SEA said:

Sunshine is not possible at night! 

48% of possible sunshine hours means 48% of daylight hours.   That is a more meaningful way to look at it.   

I am well aware that we lose 50% of the year right off the bat because it's nighttime.   

Then what are your qualms with the maps? You said they were wrong about that.

[TT-SEA]

13 minutes ago, Phil said:

Then what are your qualms with the maps? You said they were wrong about that.

Its silly to include night in sunshine percentage.  You can't get higher than 50% then.  The base should be possible sunshine hours... that means when the sun is actually up.    

[AmunRAEL]

Warm waters

https://share.newsbreak.com/4l3v7eda

[AmunRAEL]

Averagely speaking isn't the warmest part of the day between 4-530pm in the summer? And 100-230pm during winter?

[TT-SEA]

@Phil the first map you posted literally said from sunrise to sunset.   And I said its not actually cloudy here 75% of the time.   It seems more like around 50%... and sky cover does not mean the sun is blocked out all the time.   Lo and behold... it turns out it is actually sunny in Seattle about 50% of the time during the day.   And 0% of the night... which seems pretty obvious.  

I have not changed my opinion at all in the last 3 pages of discussion.    I also think Seattle is graded against the rest of the country but would do much better when you look globally.  

[SilverFallsAndrew]

54 minutes ago, TigerWoodsLibido said:

Sometimes. Recency bias has definitely felt like a trend for sure. Going back to that 2002-03 October cold snap.

I don't think it's necessarily a "death blow" to winter. I think a big time cold snap in October probably would be though. 2002 did not feature an "early" fall. 

[Phil]

4 minutes ago, TT-SEA said:

@Phil the first map you posted literally said from sunrise to sunset.   And I said its not actually cloudy here 75% of the time.   It seems more like around 50%... and sky cover does not mean the sun is blocked out all the time.   Lo and behold... it turns out it is actually sunny in Seattle about 50% of the time during the day.   And 0% of the night... which seems pretty obvious.  

I have not changed my opinion at all in the last 3 pages of discussion.    I also think Seattle is graded against the rest of the country but would do much better when you look globally.  

That’s skycover fraction, dude.

That *actually* includes high/thin clouds like cirrus, unlike ASOS. Averages would be much lower if that was included in the climatological mean.

[TT-SEA]

1 minute ago, Phil said:

That’s skycover percentage, dude.  

That *actually* includes high/thin clouds like cirrus, unlike ASOS. 

Exactly.   That is my point.   

 

[Phil]

1 minute ago, TT-SEA said:

Exactly.   That is my point.   

 

Ok, but the averages you’re quoting (50% possible sunshine hrs) don’t include that. Many days that are largely “sunny” at the surface have high clouds over a good chunk of the sky.

[TT-SEA]

Just now, Phil said:

Ok, but the averages you’re quoting (50% possible sunshine hrs) don’t include that.

We can go round and round forever.   I said it felt like the sun is shining about 50% of the time in the Seattle area over the course of the year.  And our cloudy reputation is really earned in the winter months.   I still say the same thing.   No idea what your point is.   

[Phil]

Just now, TT-SEA said:

We can go round and round forever.   I said it felt like the sun is shining about 50% of the time in the Seattle area over the course of the year.  And our cloudy reputation is really earned in the winter months.   I still say the same thing.   No idea what your point is.   

That’s exactly how I feel about what you’re saying.

I initially referenced sky cover, you referenced sunshine hours at the surface. They’re different things. And I tried to point that out multiple times, lol.

[AmunRAEL]

As much I love airshows it's true it's not good for the air or overall environment including for humans esp the smoke they release 

https://www.theurbanist.org/2023/08/02/op-ed-its-time-for-seattle-to-cancel-the-blue-angels/

[ShawniganLake]

It’s pretty cloudy here right NOW.