June 2017 Observations and Model Discussion for the Pacific Northwest

[TT-SEA]

00Z ECMWF is dry for the 4th of July... looks partly sunny and in the low 70s.

 

And turning warmer the next day on that run.

[Phil]

For example, my screw-up last week was within the *intraseasonal* range of pattern progression, which is something entirely different than the seasonal-scale, analog based predictions thrown around here on a regular basis. So many people conflate the two and it's a huge mistake.

 

Seasonal analogs will rarely (if ever) run homogenously with the present system-progression on subseasonal timesales through an entire season. Any idea to the contrary is ludicrous.

[Phil]

Yes... 1993 had merits on a large scale. But it was almost the opposite result locally which is what most of us actually care about.

On what timescale, though? Over the last 10 days? Sure.

 

Looking over the last several months, though, it was/is a great system-state analog. So, are you drawing these conclusions based on the last 10 days alone? If so, don't be shocked if/when the system reverts to a more 1993-ish state in the WHEM.

[TT-SEA]

00Z ECMWF shows a quick moving trough on Monday into Tuesday and then back to a more ridgy pattern and warmer again. Certainly not a big pattern change to troughy and cool for any length of time.

[Front Ranger]

Do you ever bother to read before responding? Not trying to be harsh, but you'll learn faster if you'd kindly shut up and read replies more thoroughly.

 

The low frequency (seasonal) system state has been (and remains) troughy. You're looking at a 4 week (subseasonal) mean and drawing incorrect conclusions as a result. The first "half" of summer will finish troughy in the means. It will be even more pronounced when tuned to a trimonthly resolution.

 

I can only go by how this summer has gone so far. June 1 to date. It has not been troughy. Even if we extended it to include the last week or last couple weeks of May, that period to date has definitely not been troughy. So there's just no way to argue the summer season is off to a troughy start.

 

It remains to be seen how the first half of summer will finish overall.

[Phil]

I can only go by how this summer has gone so far. June 1 to date. It has not been troughy. Even if we extended it to include the last week or last couple weeks of May, that period to date has definitely not been troughy. So there's just no way to argue the summer season is off to a troughy start.

 

It remains to be seen how the first half of summer will finish overall.

You're still confused. My prediction (which you referenced) was seasonal in timescale. You can't draw seasonal-scale conclusions based on subseasonal-scale data. Do you know why this is?

 

It's not possible to accurately "analog" the subseasonal pattern progression, without secondary extrapolation and/or statistical interpolation. Anyone claiming otherwise is a buffoon.

[Front Ranger]

Huh? Slow down there, sparky.

 

1) The UV200 NPAC jet was the 4th strongest on record for the month of June. You're confusing the longitude of the extension via diabatic forcing, and the strength of the jet during the extension.

 

2) It has/will be a troughy start to summer in the PNW. The first half of July will be troughy, as did more than half of June.

 

 

You're still confused. My prediction (which you referenced) was seasonal in timescale. You can't draw seasonal-scale conclusions based on subseasonal-scale data. Do you know why this is?

 

There's not really any way to interpret this other than you saying it has been a troughy start to summer in the PNW, and that will continue through the first half.

 

The observed data so far simply does not support that. Doesn't mean it can't somehow end up troughy June 1 - July 15, as you're still predicting.

[Phil]

"Seasonal", in the proper context, refers either to a trimonthly period, or a particular timeframe of interest smoothed on a trimonthly time-resolution.

 

These 3-4 week oscillations are intraseasonal/subseasonal at which point the entire nature of the forecast is different.

[Phil]

There's not really any way to interpret this other than you saying it has been a troughy start to summer in the PNW, and that will continue through the first half.

In response to your quoting of my SEASONAL forecast. I didn't forecast for a select 2 weeks in June. I only forecasted for the *entire* first half of summer, which will run for another 4 weeks.

 

Why is this so difficult for you to grasp?

 

The observed data so far simply does not support that. Doesn't mean it can't somehow end up troughy June 1 - July 15, as you're still predicting.

There is no data within the resolution-period required to draw these conclusions.

 

The first half of summer, in its entirety, is the only timeframe I was forecasting for. Not a select 2 week period within it. Get it?

[Phil]

So sick of debating these simpleton semantics. It's always with the same individual, too.

[TT-SEA]

In response to your quoting of my SEASONAL forecast. I didn't forecast for a select 2 weeks in June. I only forecasted for the *entire* first half of summer, which will run for another 4 weeks.

 

Why is this so difficult for you to grasp?

 

 

There is no data within the resolution-period required to draw these conclusions.

 

The first half of summer, in its entirety, is the only timeframe I was forecasting for. Not a select 2 week period within it. Get it?

 

 

I understand we have to wait until 7/15 to see the June 1 - July 15 period... but we can certainly look at June as well.

 

You make lots of forecasts.   You said troughing would return "in a big way" after the first few days of June and last for "several weeks".    

 

There was also this forecast...

 

 

Let's get real with it. Detailed format.

 

My thoughts are based on historical progressions of the tropical NPAC thermo-convective gradient under descending QBO easterlies and dominant EHEM/Indo forcing:

 

June: Cool month overall for PNW. Ridging builds offshore early in the month, setting up downstream trough in western US including PNW. Second half of June is a more classic Niña pattern with ridges in the NPAC and SE US, trough axis centered a bit west of the continental divide.

 

July: Normal to slightly warm month in the PNW with a possible warm stretch early or mid month. Poleward shifted NPAC ridge and a -NAO will drive a more meandering flow over NW North America, could be more of a GOA-centered ridge that licks AK/EPO area and forces a few ULLs offshore for a few bouts of westerly/southwesterly flow. Late month flips +EPO.

 

August: Cool month in coastal PNW, more GOA trough, NPAC ridge shifts westward, ridging develops over intermountain west. Could be a stronger UV200 jet compared to normal. Should be a stronger -NAO, too.

 

So, what are your thoughts? 

 

[Phil]

I understand we have to wait until 7/15 to see the June 1 - July 15 period... but we can certainly look at June as well.

 

You make lots of forecasts. You said troughing would return "in a big way" after the first few days of June and last for "several weeks".

 

There was also this forecast...

My intraseasonal timing was way off. But I still like the low frequency signal I'm getting. Again, important to differentiate between the two.

[Phil]

12z GFS data is going to be delayed, according to NCEP.

[TT-SEA]

12z GFS data is going to be delayed, according to NCEP.

 

I see that.  

[TT-SEA]

12Z GFS is fairly warm for Thursday - Sunday.  

[TT-SEA]

And a nice improvement on the 12Z GFS for the 4th... not really troughy at all on this run.   500mb heights are pretty high in fact.  Looks really nice... maybe even above normal. 

 

http://www.tropicaltidbits.com/analysis/models/gfs/2017062712/gfs_z500a_namer_31.png

 

http://www.tropicaltidbits.com/analysis/models/gfs/2017062712/gfs_T2ma_nwus_31.png

[Kayla]

In response to your quoting of my SEASONAL forecast. I didn't forecast for a select 2 weeks in June. I only forecasted for the *entire* first half of summer, which will run for another 4 weeks.

 

Why is this so difficult for you to grasp?

 

 

There is no data within the resolution-period required to draw these conclusions.

 

The first half of summer, in its entirety, is the only timeframe I was forecasting for. Not a select 2 week period within it. Get it?

 

Probably time to pull the ripcord kiddo. Writing is all over the walls for an above average first half of summer for the PacNW and most of the west. Troughy or not.

[Deweydog]

Background states. It's all about background states and ball bearings these days, guys. Thermometers and eye balls are archaic and inaccurate.

[Front Ranger]

Probably time to pull the ripcord kiddo. Writing is all over the walls for an above average first half of summer for the PacNW and most of the west. Troughy or not.

 

He'll have none of this semantical buffoonery.

[BLI snowman]

This has been a chilly month in my book. We only had one record heat wave and overall it didn't come all that close to June 2015. I have a feeling that in the years to come people will still be talking about the episode of troughing that we had. Very memorable.

[Phil]

Probably time to pull the ripcord kiddo. Writing is all over the walls for an above average first half of summer for the PacNW and most of the west. Troughy or not.

Why? I didn't make a surface temperature forecast, given what happened last year. I drew some extrapolations, but it's clear to me that the near-surface boundary layer is very fickle in the lowland PNW compared to out east.

[Jesse]

Aside from a very small blip around the 4th of July, the 12z ensembles look above average the next two weeks.

[Phil]

The 12z GEFS depiction of the tropical convection certainly favors warmth. http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=global&pkg=chi200&runtime=2017062712&fh=162&xpos=0&ypos=0

 

Then again, it looks nothing like the EPS/ECMWF. The GEFS centers it at 180-150W, while the EPS centers it at 120-150E:

[TT-SEA]

Aside from a very small blip around the 4th of July, the 12z ensembles look above average the next two weeks.

 

That should about wrap up our 6 weeks of cold, deep troughing.   Hopefully we can turn it around and get some ridging for 6 weeks after that.  

[Jesse]

That should about wrap up our 6 weeks of cold, deep troughing. Hopefully we can turn it around and get some ridging for 6 weeks after that.

I'm sure we will. That will be the part of the forecast that he nails.

[TT-SEA]

12Z ECMWF trending farther north with our trough early next week.

 

Here is the 12Z run from today... appears to be zipping by to the north on Monday.

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017062712/ecmwf_z500a_namer_7.png

 

Here was the 12Z run from yesterday... quite a change. 

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017062612/ecmwf_z500a_namer_8.png

[Kayla]

Why? I didn't make a surface temperature forecast, given what happened last year. I drew some extrapolations, but it's clear to me that the near-surface boundary layer is very fickle in the lowland PNW compared to out east.

 

Upper air, background state, etc, is all a moot point if in the end the surface levels do exactly the opposite of predicted. Maybe it just goes to show that we still have very little knowledge on how all these variables affect the lower and even the upper levels.

 

Not saying you don't know your stuff, because you do and have nailed a lot of forecasts which isn't easy to do. We can all learn greatly from missed forecasts. 

[Phil]

Have to wonder if convective coupling is being enhanced over the central Pacific, even if it's vertically shallow. This isn't showing up in the VP200 data, but it's clearly there in the OLR data. So the effect off-equator is questionable.

 

Looking at SSTAs relative to the global mean, the warm SSTs are centered right over the -OLR anomaly, which would suggest that there is an effect:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/A86CEC51-8EFA-497B-8046-052D50B45611_zpsyh1so1sc.jpg

 

Should this persist on the low frequency, it could favor western warmth in the long run, via an an eastward displacement of the NPAC anticyclone. Yet, the subsurface warmth is so shallow it won't take much to kill it.

[TT-SEA]

4th of July looks great on the 12Z ECMWF surface map... no low clouds to start the day and just some high clouds in the morning with highs in the 70s to low 80s.  

[Phil]

12Z ECMWF trending farther north with our trough early next week.

 

Here is the 12Z run from today... appears to be zipping by to the north on Monday.

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017062712/ecmwf_z500a_namer_7.png

 

Here was the 12Z run from yesterday... quite a change.

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017062612/ecmwf_z500a_namer_8.png

Nope. Still there July 4th and beyond:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/DAA0DD59-AE51-4999-ABC9-0AE18B4670F4_zpsmym5hegz.png

[TT-SEA]

Have to wonder if convective coupling is being enhanced over the central Pacific, even if it's vertically shallow. This isn't showing up in the VP200 data, but it's clearly there in the OLR data. So the effect off-equator is questionable.

 

Looking at SSTAs relative to the global mean, the warm SSTs are centered right over the -OLR anomaly, which would suggest that there is an effect:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/A86CEC51-8EFA-497B-8046-052D50B45611_zpsyh1so1sc.jpg

 

Should this persist on the low frequency, it could favor western warmth in the long run, via an an eastward displacement of the NPAC anticyclone. Yet, the subsurface warmth is so shallow it won't take much to kill it.

 

You always seem to use strong language to describe background states that favor western troughing and very timid language to describe situations that favor ridging.   

[Jesse]

Have to wonder if convective coupling is being enhanced over the central Pacific, even if it's vertically shallow. This isn't showing up in the VP200 data, but it's clearly there in the OLR data. So the effect off-equator is questionable.

 

Looking at SSTAs relative to the global mean, the warm SSTs are centered right over the -OLR anomaly, which would suggest that there is an effect:

 

Should this persist on the low frequency, it could favor western warmth in the long run, via an an eastward displacement of the NPAC anticyclone. Yet, the subsurface warmth is so shallow it won't take much to kill it.

Warmth in the short term and long run. Love it!

[TT-SEA]

Nope. Still there on the 4th of July evening:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/DAA0DD59-AE51-4999-ABC9-0AE18B4670F4_zpsmym5hegz.png

 

 

Nope?   It did not trend farther north and weaker for Monday?    The entire July 1-4 period has trended much less troughy over the last few runs.   

 

Side note... the new 12Z ECMWF surface map for Tuesday and Wednesday (7/4 and 7/5) shows sunshine and highs in the 70s to low 80s.   

[TT-SEA]

And after that deep trough on the 4th and 5th that plummets the high temps in Portland to the low 80s... we return to ridging and can finally get out of the freezer! 

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017062712/ecmwf_z500a_namer_10.png

[TT-SEA]

Day 10 on the ECMWF...

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017062712/ecmwf_z500a_namer_11.png

 

   Looks very troughy for July 1-15... much like all of June.    

[Phil]

Interesting to note: This recent stretch of warmer PNW summers coincides perfectly with the shutdown in Atlantic tropical activity since 2013.

 

While it's well known that Atlantic subsidence/+NAO favors western ridging during the summer, it hasn't often been looked at from a seasonal perspective.

[Phil]

Day 10 on the ECMWF...

 

Looks very troughy for July 1-15 much like all of June.

Trolling me won't help your karma.

 

Gonna be a rough stretch for you after this solar minimum.

[TT-SEA]

Trolling me won't help your karma.

 

Gonna be a rough stretch for you from 2020-2024.

 

Ahhh... its always in the future.   Default trolling ammunition!  I remember that 2016-19 was going to be a rough stretch too.    

[Jesse]

Ahhh... its always in the future.   Default trolling ammunition!  I remember that 2016-19 was going to be a rough stretch too.    

 

I remember that as well.

[Phil]

Ahhh... its always in the future. Default trolling ammunition! I remember that 2016-19 was going to be a rough stretch too.

Never said that, but if it makes you feel better, then go for it.

 

Strong Niñas cluster after solar minimum. Nothing new, but the coming minimum looks..just a tad deeper than most.