July 2019 Weather Discussion for the PNW

[Front Ranger]

And here is the 850mb map from the same 12Z GFS ensembles... pretty clear signal for western warmth just like the EPS.

 

 

 

850mb chart givers a much more honest/complete picture. Shows how much spread there is and you can see individual cold members too. Mean works out to near average, maybe a little above. You can keep posting lots of orange maps if you find them soothing, of course. No one’s going to stop you.

 

I wonder if both sites are showing the new GFS data? I just noticed today you can still access the old GFS on Tropical Tidbits.

 

And the legacy GFS is showing a cooler pattern in the LR than the new one.

[TT-SEA]

I wonder if both sites are showing the new GFS data? I just noticed today you can still access the old GFS on Tropical Tidbits.

 

And the legacy GFS is showing a cooler pattern in the LR than the new one.

 

 

Ahhh... maybe the chart is still linked to the old GFS?   I know the WB maps are linked to the new GFS.   I have been comparing it to the old GFS on Tropical Tidbits.

[TT-SEA]

12Z ECMWF backed WAY off on the precip amounts with the system later in the week.   All of this comes on Thursday.

 

[Jesse]

Is Hood River really running that cold this month??

 

Edit: Just checked, they are running a -1.1 departure. That map shows a -6 to -8 departure for whatever reason.

 

Also doesn't look nearly cold enough for Bozeman. Throw it out!

[Jesse]

12Z Euro certainly doesn't look like it's heading toward a big ridge at hour 192.

[Deweydog]

Either way, it's still wrong. I don't see any stations running more than -2 on either side of the gorge.

 

Guess we can't use that fun map anymore!!

Well that ruins my Saturday...

[Jesse]

Either way, it's still wrong. I don't see any stations running more than -2 on either side of the gorge.

 

Guess we can't use that fun map anymore!!

 

Meh. It gives a general idea that should be taken with a grain or two of salt. Not unlike the 10-15 day temperature anomaly maps that are posted/overanalyzed much more frequently when the pattern is favorable.

[TT-SEA]

Friday - Sunday look quite sunny and pleasant on the 12Z ECMWF... similar to the last couple runs.

[Jesse]

Pretty nice morning. 68 and partly cloudy currently after a low of 61. Feels like we have a little more marine influence today than the last few.

[Phil]

Check out the divergence over the IO towards the end of the 12z GEFS. Not a clean wavenumber and there’s interhemispheric dissonance w/ a weird N-S type communication in the wave stations, but that is the farthest thing from the typical forcing structure (by longitude) that would preceding a “ridgy” pattern in the West (running it forward into August, at least).

 

I’m really starting to doubt this is a prolonged warm up (as in, beyond a week or two) should this progression have any legitimacy.

 

[Jesse]

Friday - Sunday look quite sunny and pleasant on the 12Z ECMWF... similar to the last couple runs.

500mb pattern looks totally different, though. Probably more important than surface details happening to match up.

[Frontal Snowsquall]

12Z ECMWF backed WAY off on the precip amounts with the system later in the week. All of this comes on Thursday.

 

At least it has the heaviest precipitation directed at the areas that are in the worst drought conditions.

 

[Jesse]

At least it has the heaviest precipitation directed at the areas that are in the worst drought conditions.

 

 

Why would you want the drought to go away. Don’t you like drought? It’s EXTREME.

[TT-SEA]

500mb pattern looks totally different, though. Probably more important than surface details happening to match up.

 

The handling of the late week trough has been different on most runs... but it appears that it starts warming up over the weekend and the ridge begins to retrograde around 7/22 or 7/23.     The EPS has shown this timing for several runs now.   The 12Z ECMWF agrees.

[Phil]

The weather on the north coast is pretty much irrelevant to what is happening here. Wasn’t it 2017 that we were baking under a heat ridge and blanketed in smoke from the B.C. interior. Meanwhile Phil was doing a little fishing off Hippa Island in rain squalls and 70mph winds.

That was a blast. Reminded me of tropical storm Fay in 2008 in GA with the wind speeds. I wish every second or third summer day was like that.

 

Coolest part was the mini tornadoes on the inlets and waterways caused by winds blowing over/between/around the ridges, producing turbulent eddies and crossdrafts.

[Jesse]

The handling of the late week trough has been different on most runs... but it appears that it starts warming up over the weekend and the ridge begins to retrograde around 7/22 or 7/23.     The EPS has shown this timing for several runs now.   The 12Z ECMWF agrees.

 

How the trough is ultimately handled will affect what happens afterward.

[TT-SEA]

How the trough is ultimately handled will affect what happens afterward.

 

 

Does not seem like it actually... it seems like something bigger is driving the retrogression of the ridge and what happens over the next week in the PNW is irrelevant to that happening beginning around 7/22 or 7/23.

[Jesse]

The difference betweem hour 240 on last night's Euro and on today's is pretty extreme. Probably not good to put a lot of stock into long range solutions at the moment.

[Frontal Snowsquall]

Friday - Sunday look quite sunny and pleasant on the 12Z ECMWF... similar to the last couple runs.

That sounds good. Great timing for weekend activities.

[TigerWoodsLibido]

12Z ECMWF backed WAY off on the precip amounts with the system later in the week.   All of this comes on Thursday.

 

 

Same amount here.  Goose egg.  Much as I enjoy the cooler summer than the last several years, rain is fine, I just like it more when it's at night.

 

Tim, maybe you can spend some more time south of you if you have vacation time in the summer. We have had almost exclusively beautiful summer weather since late April here.

[Jesse]

Does not seem like it actually... it seems like something bigger is driving the retrogression of the ridge and what happens over the next week in the PNW is irrelevant to that happening beginning around 7/22 or 7/23.

So surprising you'd have this opinion!

 

#nocloudshocker

[TT-SEA]

So surprising you'd have this opinion!

 

#nocloudshocker

 

This is different than the last month when ridges would appear for one run and then disappear.   And I am pretty sure the retrogression is being driven by the tropics next week.

 

The late week trough is being de-clawed a little with each run and the retrogression is being shown consistently now.    Something has changed.

[Phil]

How the trough is ultimately handled will affect what happens afterward.

I sort of disagree. I think the manner in which the trough is being handled, and what happens afterwards, are consequences of large scale-external forcings on the wavetrains (run-to-run changes in AAM balance and tropical convection). The trough itself doesn’t affect it..what is affecting the trough affects it.

 

If the trough is handled in a certain way that appears to “open the door” to continuing/terminating the pattern, it’s merely the system state itself that is changing (or changing the pattern, depending on your frame of reference).

[Jesse]

This is different than the last month when ridges would appear for one run and then disappear. And I am pretty sure the retrogression is being driven by the tropics next week.

 

The late week trough is being de-clawed with each run and the retrogression is being shown consistently now. Something has changed now.

There were ridges in many consecutive runs over the last month. They were always out around days 8-10, though.

[TT-SEA]

I sort of disagree. I think the manner in which the trough is being handled, and what happens afterwards, are consequences of large scale-external forcings on the wavetrains (run-to-run changes in AAM balance and tropical convection).

 

If the trough is handled in a certain way that appears to “open the door” to continuing/terminating the pattern, it’s actually just the system state itself that is changing (or changing the pattern, depending on your frame of reference).

 

I don't understand all of this and cannot articulate it like you... but that is the sense I get as well.

[Jesse]

I sort of disagree. I think the manner in which the trough is being handled, and what happens afterwards, are consequences of large scale-external forcings on the wavetrains (run-to-run changes in AAM balance and tropical convection).

 

If the trough is handled in a certain way that appears to “open the door” to continuing/terminating the pattern, it’s actually just the system state itself that is changing (or changing the pattern, depending on your frame of reference).

Yeah yeah, chicken or the egg. You know what I meant though.

[TT-SEA]

There were ridges in many consecutive runs over the last month. They were always out around days 8-10, though.

 

The EPS never showed any of it... the best I could find was slightly less troughy maps.   Now its easy again... the EPS is showing the same thing on every run and its moving up in time as expected.

 

This is a clear signal...

 

[Jesse]

The EPS never showed any of it... the best I could find was slightly less troughy maps. Now its easy again... the EPS is showing the same thing on every run and its moving up in time as expected.

 

This is a clear signal...

 

 

Yep, I’m sure we’re gonna roast.

[seattleweatherguy]

He has family in Everett.

Nice love to meet with Phil one day. I still remember the time that geology teacher couldn’t win that one argument

[Phil]

Yeah yeah, chicken or the egg. You know what I meant though.

Yeah, the trough itself is not affecting what happens thereafter (to a significant extent). It’s what is causing the trough to behave differently in the first place that is altering the progression.

[TT-SEA]

Yep, I’m sure we’re gonna roast.

 

Possibly.

 

Devil will be in the details of course.   The pattern will be at least favorable for warmer and sunnier weather than we have seen for the past month.

[Phil]

The EPS never showed any of it... the best I could find was slightly less troughy maps. Now its easy again... the EPS is showing the same thing on every run and its moving up in time as expected.

 

This is a clear signal...

 

You’re forgetting mid/late June, when all the focus was on the 4th of July. The EPS and the other models were all flipping to warm/ridgy starting July 1st, and significantly so.

 

It started getting watered down once it got inside D7, starting with a little ULL inside the retrograding ridge, and eventually it was killed off completely inside D4 as the NPO handling changed due to minor differences in upstream triggers.

[Jesse]

Yeah, the trough itself is not affecting what happens thereafter (to a significant extent). It’s what is causing the trough to behave differently in the first place that is altering the progression.

 

Of course, but run to run swings at hour 240 are still worth paying attention to, since as you said, it's how the overall pattern is making the trough behave that is important. 

 

Tim is bandwagoning now, but it's not the point he was originally making.

[TT-SEA]

You’re forgetting mid/late June, when all the focus was on the 4th of July. The EPS and the other models were all flipping to warm/ridgy starting July 1st, and significantly so.

 

It started getting watered down once it got inside D7, and eventually was killed off inside D4.

True.

 

Could be a delayed but not denied situation.

[ShawniganLake]

I wonder if both sites are showing the new GFS data? I just noticed today you can still access the old GFS on Tropical Tidbits.

 

And the legacy GFS is showing a cooler pattern in the LR than the new one.

I’m not sure if the old version of the german site was updated with the new GFS. I don’t see the operational even on that chart. Wasn’t it indicated by a heavier green line before. The updated version of the site does have the new GFS in its ensemble

[Jesse]

Hope the EPS site doesn't crash due to the refresh button being hit 200 times a minute from a North Bend IP address this afternoon. I want to see it too.

[TT-SEA]

Hope the EPS site doesn't crash due to the refresh button being hit 200 times a minute from a North Bend IP address this afternoon. I want to see it too.

I wait until 1:10 to check it. And then its all done. No need to refresh.

 

I am pretty excited to see a pattern that allows the sun to shine for a few days here. Seems like a small request for July. Whatever it takes.

[TacomaWaWx]

Back to back beautiful sunny days in Tacoma. Currently up to 68 and mostly sunny now. Yesterday and today have been the nicest days we’ve had in what seems like awhile. Pretty much everyday outside of a few has been cloudy-mostly cloudy since mid June.

[Deweydog]

Sun is out here. Kinda.

[Phil]

True.

 

Could be a delayed but not denied situation.

Could be. I think part of that bust was the Eurasian monsoonal initiation which tends to incur gyrations in the state predictability through the Pacific conduits.

 

Then again, you could argue for poorly resolved intraseasonal modes (Indo-Pacific barrier/various model biases/limitations, etc) which could lead to a similar outcome this time, or a significantly shortened duration.

 

Hard to know. But you generally would not expect a strong ridge in the West for a prolonged period of time if divergence is clearly centered in the EHEM. In this case it’s admittedly more complicated with a muted background state and weak MJO with little in the way of interhemispheric homogeneity in spite of a straightforward line of communication (rapid CCKW cycles and phase changes stand out the most on the subseasonal scale).