July 2016 Observation and Model Discussion for the Pacific Northwest

[Phil]

9/95 was hot.

August of 1995 wasn't, though, despite all the factors you're claiming favor lowland warmth. Neither was 8/83. Why might that be?

 

The answer, again, lies in the specific nature of the pattern and streamflow aloft. If the recent July trough axis had been located merely 200 miles east with a more negative tilt, July would've averaged much cooler at the coast, relative to average, while inland areas would have run warmer.

[TT-SEA]

 

-4 at Seattle WFO, which is actually a better barometer of Seattle proper.

 

 

One of the few days this month with WFO SEA cooler than SEA.    Most days WFO SEA has been the same or a little warmer than SEA.

 

Yesterday there was a c-zone signature to the clouds with Seattle northward solidly cloudy all day while SEA got into some sunshine at times with SW winds.     Pretty much the only way it seems for WFO SEA to be colder than SEA.

[TT-SEA]

August of 1995 wasn't, though, despite all the factors you're claiming favor lowland warmth. Neither was 8/83. Why might that be?

 

The answer, again, lies in the specific nature of the pattern and streamflow aloft. If the recent July trough axis had been located merely 200 miles east with a more negative tilt, July would've averaged much cooler at the coast, relative to average, while inland areas would have run warmer.

 

 

July of 1995 was warm.   Are you just cherry picking the worst month from each analog year just to excite certain people and more importantly try to piss off other people?   

[Phil]

Very likely to continue in August in the Puget Sound region.

Okay, but again, that would require the pattern to essentially emulate that of July (general troughing is almost a foregone conclusion, in my opinion).

 

Given changes in the systematic drivers, cell climatology, and history in said progressions, what supports this idea? It could very well turn out correct, but I don't how anyone can predict something like that. It'd be mostly guesswork.

[TT-SEA]

Okay, but again, that would require the pattern to essentially emulate that of July (general troughing is almost a foregone conclusion, in my opinion).

 

Given changes in the systematic drivers, cell climatology, and history in said progressions, what supports this idea? It could very well turn out correct, but I don't how anyone can predict something like that. It'd be mostly guesswork.

 

 

Gut feeling... local history in years with significant troughing in June and the first half of June... still warm SSTAs offshore... etc.

 

Whatever.   

 

I know the Puget Sound region tendencies pretty well.  

[Phil]

July of 1995 was warm. Are you just cherry picking the worst month from each analog year just to excite certain people and more importantly try to piss off other people?

Are you paying attention? I'm using these months to make a point regarding the drivers of surface temperature anomalies. These months (a small example of many) ended up cooler than average in the lowlands despite warm SSTAs, urbanization, weaker Niña/-AAM backgrounds, etc.

 

The PNW lowlands average just as many cooler than average summers/summer months as they do warmer than average months, and the vast majority of these occur in La Niña summers. Thats why we call it an "average", a aggregated compilation of tendencies over an extended period of time.

[Front Ranger]

Really Jared??

 

Sorry, I missed it in the sea of SEA updates.

[Phil]

Gut feeling... local history in years with significant troughing in June and the first half of June... still warm SSTAs offshore... etc.

 

Whatever.

 

I know the Puget Sound region tendencies pretty well.

What years are you looking at? I thought you were relying on surface temperature departures to determine the nature of ridging/troughing? If both June and July average warm, are you considering those to be troughy months?

[Front Ranger]

One of the few days this month with WFO SEA cooler than SEA.    Most days WFO SEA has been the same or a little warmer than SEA.

 

Yesterday there was a c-zone signature to the clouds with Seattle northward solidly cloudy all day while SEA got into some sunshine at times with SW winds.     Pretty much the only way it seems for WFO SEA to be colder than SEA.

 

It's funny, even though SEA's longterm average is about 1.3 colder overall than WFO Seattle, WFO was colder in both 2013 and 2014. And cooler so far in 2016.

[TT-SEA]

Are you paying attention? I'm using these months to make a point regarding the drivers of surface temperature anomalies. These months (a small example of many) ended up cooler than average in the lowlands despite warm SSTAs, urbanization, weaker Niña/-AAM backgrounds, etc.

 

The PNW lowlands average just as many cooler than average summers/summer months as they do warmer than average months, and the vast majority of these occur in La Niña summers. Thats why we call it an "average", a aggregated compilation of tendencies over an extended period of time.

 

 

I think warmer than normal is more common in the last 15 years.    Maybe a combination of things.   Could be below normal in August here... we will see.    That would set up a warm September most likely.     

 

I think a below normal August this year would also need to be a wet August.    Could happen.

[Front Ranger]

Very likely to continue in August in the Puget Sound region.  

 

You are getting overconfident again.

[TT-SEA]

What years are you looking at? I thought you were relying on surface temperature departures to determine the nature of ridging/troughing? If both June and July average warm, are you considering those to be troughy months?

 

 

I usually don't look at the monthly departure.   That can be so misleading to gauging the overall timing and nature of a month.

 

I look at color-coded daily records.   Periods of cool/wet and warm/dry stand out very well.   Sometimes those periods cross between months and skews things one way or another.  

 

When I see long runs of cooler/damp weather in June and early July... usually I see long runs of warm/dry weather in late July and August.     The opposite is true when June is mostly warm and dry... August tends to be cooler/wetter.  

 

June might have been warm thanks to a few hot days... but looking at the daily records it would be clear to see that a large part of the month was actually troughy.  

[James Jones]

It's been a really long time since the region saw a legitimately cool August. 2000 was probably the last time, but even that was nothing impressive at all compared to many Augusts from the 1970s and earlier. 

 

I guess you could go with the "we're due" logic, but as we know weather doesn't really work that way.

[TT-SEA]

You are getting overconfident again.

 

 

See later posts.   Compromising.

[Phil]

I think warmer than normal is more common in the last 15 years. Maybe a combination of things. Could be below normal in August here... we will see. That would set up a warm September most likely.

 

I think a below normal August this year would also need to be a wet August. Could happen.

August should definitely feature more -EPO with stronger ridging to the N/W versus July. Probably somewhat less impressive troughing from a 500mb perspective, but should this pattern verify, regional streamflow should be more NWerly vs W/SWerly.

[TT-SEA]

August should definitely feature more -EPO with stronger ridging to the N/W versus July. Probably somewhat less impressive troughing from a 500mb perspective, but should this pattern verify, regional streamflow should be more NWerly vs W/SWerly.

 

 

That tends to be sunnier here... SW flow with an inversion is a recipe for cool weather in the summer.   That and a genuine rainy pattern.

[TT-SEA]

Sorry, I missed it in the sea of SEA updates.

 

 

I post everything SEA related.    

[Phil]

I usually don't look at the monthly departure. That can be so misleading to gauging the overall timing and nature of a month.

 

I look at color-coded daily records. Periods of cool/wet and warm/dry stand out very well. Sometimes those periods cross between months and skews things one way or another.

 

When I see long runs of cooler/damp weather in June and early July... usually I see long runs of warm/dry weather in late July and August. The opposite is true when June is mostly warm and dry... August tends to be cooler/wetter.

 

June might have been warm thanks to a few hot days... but looking at the daily records it would be clear to see that a large part of the month was actually troughy.

Okay, so what analog years are you referencing, which match this year's progression? I'd be interested to look at this, given there aren't very many. Certainly, the 1973/1998/2010 years haven't been good analogs.

 

Always important to factor in drivers (ENSO, etc) when isolating tendencies. I've found the ESRL site to be extremely valuable in regards to analoging.

[Phil]

That tends to be sunnier here... SW flow with an inversion is a recipe for cool weather in the summer. That and a genuine rainy pattern.

The years that match this progression are just about average in terms of precipitation, but cooler than average at the surface, with the coolest anomalies located west of the cascades. Probably marine influence w/ less in the way of ULLs spinning just offshore.

[TT-SEA]

The years that match this progression are just about average in terms of precipitation, but cooler than average at the surface, with the coolest anomalies located west of the cascades, in this case.

 

Probably marine influence, with less frequent closer low pressure systems.

 

 

Could be.   We will see.   

 

I can't remember now all of the years that I have looked at back in early June.    Certainly recent years like 1980, 1983, 1988, 1995, 2007, 2010.     

[Phil]

Could be. We will see.

 

I can't remember now all of the years that I have looked at back in early June. Certainly recent years like 1980, 1983, 1988, 1995, 2007, 2010.

Good to know, thanks. Would be nice if we had solid upper air data before 1979, but unfortunately we don't.

[Phil]

It's been a really long time since the region saw a legitimately cool August. 2000 was probably the last time, but even that was nothing impressive at all compared to many Augusts from the 1970s and earlier.

 

I guess you could go with the "we're due" logic, but as we know weather doesn't really work that way.

Funny you mention that, because 2000 happens to be the top August analog on the d8-14 CPC superensemble mean. Looks like 1993 showing up for the same target date (August 8th).

 

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814analog.off.gif

[TT-SEA]

Funny you mention that, because 2000 happens to be the top August analog on the d8-14 CPC superensemble mean. Looks like 1993 showing up for the same target date (August 8th).

 

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814analog.off.gif

 

 

Remember... until a few days ago you were saying the first part of August would be warm.     I think you are seeing a troughy period in the first or second week and the second half of the month will be warmer/drier.    Your timing has literally been off all year and it is still happening.   Your early August ridge is arriving today.   

[Front Ranger]

It's been a really long time since the region saw a legitimately cool August. 2000 was probably the last time, but even that was nothing impressive at all compared to many Augusts from the 1970s and earlier. 

 

I guess you could go with the "we're due" logic, but as we know weather doesn't really work that way.

 

The 1970s certainly did see a trio of very cool Augusts, 1973, 1975, and 1976. 1973 (very strong Nino to Nina year) was probably the coolest August for western WA at least in the airport era. 1975 was probably the coolest region-wide.

 

Interestingly, the two hottest Augusts regionally came right before and after the 1970s, 1967 and 1981.

[Phil]

Remember... until a few days ago you were saying the first part of August would be warm. I think you are seeing a troughy period in the first or second week and the second half of the month will be warmer/drier. Your timing has literally been off all year and it is still happening. Your early August ridge is arriving today.

I've generally been about a week slow, however I believe I've determined the reason(s) for that. A procedural "adjustment" of my own, if you will.

[Front Ranger]

69 at 3 pm at SEA on 7/23. Not a warm day.

[TT-SEA]

69 at 3 pm at SEA on 7/23. Not a warm day.

Marine layer day... all guidance was showing today being cool. Going to be an evening high mostly likely.

[TT-SEA]

Troughy from 8/4 through 8/15 would be great... also hot with occasional storms in MN in that period.

[Phil]

Clown range GFS going with troughzilla 4.0.

 

At least there's finally multi-model/ensemble agreement. Going to be a tough pattern to hone in on.

[Phil]

Looks like the ECMWF will overshoot PDX and undershoot SEA again. It had PDX @ 78, SEA @ 70. Been a consistent theme for the last two weeks, must be something in the pattern.

[TT-SEA]

From Cliff Mass... I had no idea how wet it was on Thursday night and Friday morning.     Barely enough to wet the ground here which is even more strange given how much rain fell to my west.

 

[Front Ranger]

Probably some fairly chilly lows tonight in places.

[GHweatherChris]

From Cliff Mass... I had no idea how wet it was on Thursday night and Friday morning. Barely enough to wet the ground here which is even more strange given how much rain fell to my west.

 

It has to rain at a certain location to make the ground wet there.

 

And the flow was not from the west so it being wetter that way makes sense.

[MossMan]

From Cliff Mass... I had no idea how wet it was on Thursday night and Friday morning. Barely enough to wet the ground here which is even more strange given how much rain fell to my west.

 

We had next to nothing up in my area...and I was ok with that! My 2 acres of grass is finally starting to slow down.

[MossMan]

Marine layer day... all guidance was showing today being cool. Going to be an evening high mostly likely.

Clouds broke up here in the early afternoon for a very nice day. Currently 73 degrees.

[TT-SEA]

It has to rain at a certain location to make the ground wet there.

 

And the flow was not from the west so it being wetter that way makes sense.

 

 

I am not normally in one of the driest spots in the region.  It was surprising to see such high totals across a wide area with almost nothing here.   You know what I meant.  

[TT-SEA]

Clouds broke up here in the early afternoon for a very nice day. Currently 73 degrees.

 

 

We do well on these days when the marine layer is retreating in this manner... the hills create a hole in the clouds over my area early on.   We probably had sun for 75% of the day here.

 

Tomorrow we are trying out Lake Tapps.   

[TT-SEA]

73/58 so far at SEA.

 

A high at 6 p.m. is possible but not too likely.

 

So far its another -1 departure.

[Phil]

I know it's the CFS but the new run of the 12z CFS is fairly troughy throughout it's run in the long range. These are definitely types of patterns we want to see in the Winter.

 

http://maps1.pivotalweather.com/maps/models/cfs/2016072312/528/500h_anom.na.png

http://maps1.pivotalweather.com/maps/models/cfs/2016072312/660/500h_anom.na.png

http://maps1.pivotalweather.com/maps/models/cfs/2016072312/756/500h_anom.na.png

iFred moved here at the wrong time, me thinks.

[GHweatherChris]

I am not normally in one of the driest spots in the region. It was surprising to see such high totals across a wide area with almost nothing here. You know what I meant.

Being surprised you didn't get much with the flow on Thursday and Friday being what it was is what surprised me about your post.