August 2017 PNW Discussion Thread

[Phil]

Hopefully we can get a break after the first half of September. We will be looking at basically six weeks of mostly unbroken heat at that point.

I'm fairly confident there will be a pattern change when forcing leaves the Pacific, maybe during the second half of September into early October? Hard to extrapolate from here though as the Eurasia/IO area begins the transition out of its monsoonal circulation and into its winter circulation during October every year, which affects the tropical convection/MJO and how it plays on the ET wavetrain.

[Jesse]

I'm fairly confident there will be a pattern change when forcing leaves the Pacific, maybe during the second half of September into early October? Hard to extrapolate from here though as the Eurasia/IO area begins the transition out of its monsoonal circulation and into its winter circulation during October every year, which affects the tropical convection/MJO and how it plays on the ET wavetrain.

Things seems to be running ahead of schedule in regard to what you've been predicting this summer, although within a back-shifted timeframe you have still been pretty accurate. For instance, the mid-September heat seems to be making an appearance about ten days early.

 

Maybe that will mean the pattern change is earlier than you are anticipating too. I need something right now.

[Phil]

The dry stretch came to a screeching halt in 1967 with a big storm on 9/2. And October was VERY wet, with over 10" of rain for OLM.

I could definitely see strong jet/GOA trough episode sometime during the second half of September or early October. It almost has to happen at some point (IMO, probably when forcing enters the EPAC/leaves the WPAC).

[Front Ranger]

That's why I said mostly. Unnecessary flatironing here.

 

Well, "mostly unbroken" was kind of an odd choice of words. Don't take it personal!

 

Most of July was warm but not hot with some coolish days the second half of the month, then there was a lengthy warm/hot stretch the first 10 days of August, then a near normal to coolish stretch mid month, and now it's looking like a hot end to the month.

[TT-SEA]

The dry stretch came to a screeching halt in 1967 with a big storm on 9/2. And October was VERY wet, with over 10" of rain for OLM.

 

There was an amazing .09 here in my area from the big storm on 9/1 and 9/2 of 1967.   

 

September 1967 was mostly warm and dry out here.   October was wet... and November was more decent than usual with more dry days than rainy days.  

 

[Phil]

Things seems to be running ahead of schedule in regard to what you've been predicting this summer, although within a back-shifted timeframe you have still been pretty accurate. For instance, the mid-September heat seems to be making an appearance about ten days early.

 

Maybe that will mean the pattern change is earlier than you are anticipating too. I need something right now.

You have a point there. Harvey also seems to be thermomechanically feeding back on the SW US anticyclone in the recent modeling, so there's that to consider as well.

 

I wonder if there will be two heat spikes (early month and mid-month) before that GOA vortex of doom makes its move later in the month into early October?

[Anti Marine Layer]

What thread is this again?

 

Yep wrong thread, I made a mistake.

 

Today is a good day for SoCal to PNW comparisons. Here's Escondido in the May Gray, or is it June Gloom, or is it Fogust?

 

[Jesse]

Well, "mostly unbroken" was kind of an odd choice of words. Don't take it personal!

 

Most of July was warm but not hot with some coolish days the second half of the month, then there was a lengthy warm/hot stretch the first 10 days of August, then a near normal to coolish stretch mid month, and now it's looking like a hot end to the month.

I know how this summer has played out. I live here.

[stuffradio]

I know how this summer has played out. I live here.

How do we know? We need proof! You might have been lying this whole time.

 

On another note, 12Z GFS is sure roasty next weekend. 97F for Abbotsford next Saturday.

 

[TT-SEA]

Yep wrong thread, I made a mistake.

 

Today is a good day for SoCal to PNW comparisons. Here's Escondido in the May Gray, or is it June Gloom, or is it Fogust?

 

IMG_20170824_102652.jpg

 

Why do you have a house in Escondido?   

 

Technically we used to live in Escondido although our house was several miles north of the city and about half-way to Temecula.    We built our house there in 1998 and sold it in 2003.   We had a 12-acre lot in Hidden Meadows.   I know Escondido very well.  

[BLI snowman]

What model shows 48" of rain?? I can't find any location or model showing more than 27" of rainfall over the next 10 days.

 

Those are lower-res models though. They won't ever pick up the extreme amounts from localized convective bands, especially at this range. Given that, the modeled output for TX is extremely concerning. Spots of 35"+ totals appear likely, 40-50" could very well be the higher end.

[Front Ranger]

There was an amazing .09 here in my area from the big storm on 9/1 and 9/2 of 1967.   

 

Interesting. SEA had .23" with that.

[BLI snowman]

November 1967 had 17 dry days here in this area... that is outstanding for November.  

 

And then 1968 was one of the wettest years on record.

 

#thingstocome

[TT-SEA]

And then 1968 was one of the wettest years on record.

 

#thingstocome

 

Yes... we will follow 1967-68 for the next 18 months perfectly.   And then veer off completely in late December 2018.  

[TT-SEA]

Interesting. SEA had .23" with that.

 

I had .11 here last night.   Blowing away that massive storm on 9/2/1967 by .02   

[Phil]

Those are lower-res models though. They won't ever pick up the extreme amounts from localized convective bands, especially at this range. Given that, the modeled output for TX is extremely concerning. Spots of 35"+ totals appear likely, 40-50" could very well be the higher end.

Yeah, even the 12z GEFS (which holds maybe 10 pixels per map) has an ensemble mean of 26", which is truly insane.

[Front Ranger]

I know how this summer has played out. I live here.

 

 

And I know you live there.

[Front Ranger]

I had .11 here last night.   Blowing away that massive storm on 9/2/1967 by .02   

 

Hey, that early Sep 1967 storm still beats anything the region has seen since mid June!

[BLI snowman]

Yes... we will follow 1967-68 for the next 18 months perfectly.   And then veer off completely in late December 2018.  

 

I'm expecting unusually poor things from 2018-19, actually. 1918-19 was a Nino dud.

[Front Ranger]

The latest CMC actually cools things down quite a bit for the last couple days of August.

[BLI snowman]

Yeah, even the 12z GEFS (which holds maybe 10 pixels per map) has an ensemble mean of 26", which is truly insane.

 

I was kinda floored when I saw that. Massive area of 12"+, as well.

[Front Ranger]

Interesting differences in how the Euro is handling Harvey vs GFS. The GFS brings it fully ashore and then it just kind of lingers and peters out (while dumping copious rainfall), while the Euro has it hugging the coast and remaining a much more intense storm as it slowly drifts NE.

 

Hard to say which scenario would be worse overall.

[Phil]

[James Jones]

9-3-17 is the new 9-2-88!

 

Smoke is gonna ruin our chance at the all time record again  <_>

 

 

http://i.imgur.com/Gs0J4JG.jpg?1

[Front Ranger]

Euro is very hot for all of western OR late next week. Says CMC is cracked out.

[Jesse]

The only good thing I can really say about the Euro is that at least it shows a small break between the two heat events, as opposed to one continuous heatwave.

[TT-SEA]

The only good thing I can really say about the Euro is that at least it shows a small break between the two heat events, as opposed to one continuous heatwave.

 

 

12Z ECMWF for PDX:

 

[Anti Marine Layer]

I am on vacation at the Welk Resort and we are having record low maximum temperatures and empty swimming pools.

[TT-SEA]

I am on vacation at the Welk Resort and we are having record low maximum temperatures and empty swimming pools.

 

Ahhhh... we used to live on the hill right above that resort.    Empty pools?   Its almost 80 there right now.   Wimps!  

 

And the sun is coming out there now anyways.  

[Deweydog]

Ahhhh... we used to live on the hill right above that resort. Empty pools? Its almost 80 there right now. Wimps!

 

And the sun is coming out there now anyways.

I figured this was gonna prompt a webcam tour.

[Kayla]

Those are lower-res models though. They won't ever pick up the extreme amounts from localized convective bands, especially at this range. Given that, the modeled output for TX is extremely concerning. Spots of 35"+ totals appear likely, 40-50" could very well be the higher end.

 

ECMWF does pretty well usually but yeah you never know with convective banding. Hi-res 3km NAM has even less precip over the next 84 hours FWIW. I have a REALLY hard time believing anyone will see 40"+ out of this IMO. Definitely a few areas will see 30"+ but I just think 4ft of rain is a bit dramatic and unrealistic based off of current guidance.

 

Either way, it's going to be a devastating storm and I'm sure we'll be hearing a lot about Harvey over the coming days.

[TT-SEA]

I figured this was gonna prompt a webcam tour.

 

Satellite loop tells the story of the marine layer retreating down there. 

 

I hope everyone survived.  Its been a rough day in Escondido.  

[TT-SEA]

73 at PDX at 3 pm... might not make it to 78.

 

Meanwhile... SEA has been stuck at 67 for 3 hours despite plenty of sun breaks.   Looks like the first sub-70 day in almost 2 months there definitely a possibility.  

[Deweydog]

9-2-17 is the new 9-3-17!

[TT-SEA]

73 at PDX at 3 pm... might not make it to 78.

 

Meanwhile... SEA has been stuck at 67 for 3 hours despite plenty of sun breaks.   Looks like the first sub-70 day in almost 2 months there definitely a possibility.  

 

 

Nope... 70 at SEA at 4 p.m.

 

SEA will go entirely through July and August without a sub-70 high.   

 

I wonder how many times that has happened?

[James Jones]

Nope... 70 at SEA at 4 p.m.

 

SEA will go entirely through July and August without a sub-70 high.   

 

I wonder how many times that has happened?

 

Pretty sure it's never happened. Even at PDX it's only happened 3 times - 1967, 2016, and 2017.

[TT-SEA]

Pretty sure it's never happened. Even at PDX it's only happened 3 times - 1967, 2016, and 2017.

 

 

Good information... thanks.   

[wx_statman]

Nope... 70 at SEA at 4 p.m.

 

SEA will go entirely through July and August without a sub-70 high.   

 

I wonder how many times that has happened?

 

This will be the first time.

 

2003 came close with 69 & 70.

[TT-SEA]

Highs today...

 

72 at SEA

 

75 at PDX

[Jesse]

This is now also the first month in history that PDX has failed to see a max below 75.