September 2017 PNW Discussion Thread

[TT-SEA]

Shouldn't have been necessary for larger mature trees like this. Trees are dying or going into drought-induced hibernation all over the place around town this year, you see it in many of the street trees downtown as well.

 

I also find it hard to believe that large cedar trees are dependent on summer rainfall.   And its never really hot up there.

 

The region just had back-to-back wettest winters ever and summer rain is always negligible.   This has been the wettest two years ever in Seattle.   Seems odd that up there all the trees are dying from no water.

[Jesse]

My boys have been talking about the zip line course.

 

We don't mind some challenging hikes. One of my sons will mock us unless its very difficult.

Anywhere up in Indian Heaven is nice this time of year. Assuming it will be open again after the rains. The 467 acre East Crater fire should be out by then.

 

https://inciweb.nwcg.gov/incident/article/5589/41308/

[Phil]

There's also a question of Modoki vs. east-based. I've seen the 2007-08 Nina classified as Modoki before, based on the fact that Nino 4 anamolies were colder than Nino 3 during the mature phase (Jan-Mar 2008). I'm not sure what exactly our current Nina will end up as.

I think it will shift westward over the next few months, though I'm not sure about it given the +IOD. Do you have any thoughts on that?

 

I do think that where the warm SSTs set up (either in the IO or in the Indo-Pacific) will be a significant factor in the pattern progression, and as a result, will also determine the nature of the La Niña SSTA signature. Just my opinion, though.

[VancouverIslandSouth]

I also find it hard to believe that large cedar trees are dependent on summer rainfall.   And its never really hot up there.

 

The region just had back-to-back wettest winters ever and summer rain is always negligible.   This has been the wettest two years ever in Seattle.   Seems odd that up there all the trees are dying from no water.

 

It sounds like it can have an impact:

 

 

Heat: Foliage can become dull or bronzed in mid-summer from heat and desiccating winds

 

Water Stress: Cedars are relatively shallowrooted trees. They are susceptible to drought stress especially on well-drained, sandy soils. The extreme of very wet soil in the fall and winter, followed by a hot, dry summer, is very stressful for the roots.

[TT-SEA]

It sounds like it can have an impact:

 

Like I said... its never really hot up there.

 

And the cedar trees in this area should be completely acclimated to very wet winters and very dry summers.   If not... then this is natural selection.

[wx_statman]

I think it will shift westward over the next few months, though I'm not sure about it given the +IOD. Do you have any thoughts on that?

 

I do think that where the warm SSTs set up (either in the IO or in the Indo-Pacific) will be a significant factor in the pattern progression, and as a result, will also determine the nature of the La Niña SSTA signature. Just my opinion, though.

 

No, unfortunately. I haven't studied ENSO enough.

[Phil]

Holy fook @ Eurasia. Huge +SH dipole.

 

The western US ridge is intraseasonal (temporary), but if there's a way to avoid a +EPO buzzkill in 2017/18, this is it.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/72003B18-C731-4065-90E9-3BF45FF76F46_zps8w2ihr7y.png

[Geos]

Very light.   Don't expect too much today.  

 

Pouring with a wind around 20mph here right now. If only this could continue into tomorrow...

[TT-SEA]

Pouring with a wind around 20mph here right now. If only this could continue into tomorrow...

Juat sprinkles here so far.

[Phil]

OT, but it would be crazy if Jose got stuck again, then did a fujiwara dance with Maria, as some models show. Might be the only way the US avoids another landfall.

[Jesse]

PDX has now dropped to around 60 with SSW winds gusting to 30mph and light rain/drizzle. Octoberish afternoon out there.

 

That would also mean their high was likely 65, making today their coolest day since June 16th, and also their first sub-70 day since then.

[Geos]

A high of 63 here with 0.09" of rain so far. 

[ShawniganLake]

Like I said... its never really hot up there.

 

And the cedar trees in this area should be completely acclimated to very wet winters and very dry summers. If not... then this is natural selection.

I'm not sure if it's weather related but it seems like there is an unusual number of dead cedar trees in the forested areas near Shawnigan.

[ShawniganLake]

A lot drier than I was expecting today. Just 0.04" of rain and the sun is already out

[Deweydog]

Up to trace at PDX!!!

 

#prayforthedikes

[BLI snowman]

Up to trace at PDX!!!

 

#prayforthedikes

Radar looks pretty sad.

 

Cancel the fire season cancel.

[Front Ranger]

With .12" today, SEA has finally ended a nearly 3 month stretch where they saw only .02" of rain. There is no comparable period in SEA history.

[Jesse]

Radar looks pretty sad.

 

Cancel the fire season cancel.

There look to be a few more solid opportunities for widespread rainfall this coming week. And thanks to orographcs the fire areas in the Cascades are getting rain right now anyway.

 

But yeah, definitely a drier front than I anticipated today. At least it's cooled down nicely.

[Kayla]

The POAMA seasonal forecast (nailed last winter) is quite disappointing, unless you live in Alaska or maybe Tim's elevation.

 

Strongest +EPO in history?

 

 

Or Montana. Kind of looks similar to some other early winter forecasts.

[snow_wizard]

The latest progs are most impressive with the trough this week.  Really nice looking for this early in the season.

[snow_wizard]

With .12" today, SEA has finally ended a nearly 3 month stretch where they saw only .02" of rain. There is no comparable period in SEA history.

 

It hasn't been quite that dry here, but still really dry until today.

[snow_wizard]

Regardless of the modeling, it's becoming clear(er) where the battle lines are going to be drawn this year.

 

The fate of winter 2017/18 will hinge whether we can dislodge a well established +EPO. With a -QBO, the mean NPAC High location will be shifted equatorward, so it will take potent intraseasonal forcing (MJO, or strat attack) to compensate for the low frequency waveguides.

 

If we can avoid additional solar storms and maintain the cold EPAC, the circulation might favor more blocking/less +EPO, so it could be dislodged.

 

No question a 2007-08 redux is a big fear for this winter.  I would like to see something break the back of that analog fairly soon.  As people have pointed out that winter came very close to delivering the goods on a number of occasions so it wouldn't take much.

[snow_wizard]

Honestly we are pretty overdue for a winter with a lot of cool, wet WNW flow.

 

We are actually more due for a solidly cold / "dry" winter than anything.  Last winter had some of that, but still not what we are due for.

[TT-SEA]

We are actually more due for a solidly cold / "dry" winter than anything.  Last winter had some of that, but still not what we are due for.

 

I think so as well... but nature is on a 'wettest winter ever' roll right now for the last 2 years.

[DareDuck]

There look to be a few more solid opportunities for widespread rainfall this coming week. And thanks to orographcs the fire areas in the Cascades are getting rain right now anyway.

 

But yeah, definitely a drier front than I anticipated today. At least it's cooled down nicely.

Not for the Desolation, Milli, and Horse Creek Complex fires, but that shouldn't be the case by Tuesday night.

[Anti Marine Layer]

Still only a trace of rain for Portland.   We got more rain than that (.01-.02) in some spots today from thick stratocumulus clouds.

[Front Ranger]

I think so as well... but nature is on a 'wettest winter ever' roll right now for the last 2 years.

 

The actual winter itself (DJF) was not wettest, though. Dec/Jan were fairly dry. October was very wet, and then Feb-Apr.

 

Much different than the winter of 2015-16.

[Anti Marine Layer]

A lot drier than I was expecting today. Just 0.04" of rain and the sun is already out

 

Pretty much like 90% California of winter "storms" during the drought before last winter.

[Jesse]

Still only a trace of rain for Portland. We got more rain than that (.01-.02) in some spots today from thick stratocumulus clouds.

Secret's out. We are actually drier on average than you guys Sept-March.

[TT-SEA]

The actual winter itself (DJF) was not wettest, though. Dec/Jan were fairly dry. October was very wet, and then Feb-Apr.

 

Much different than the winter of 2015-16.

 

True.

[TT-SEA]

With .12" today, SEA has finally ended a nearly 3 month stretch where they saw only .02" of rain. There is no comparable period in SEA history.

 

Interestingly... the past 3 months followed the wettest Feb - Apr ever.   Year of extremes.  

[Front Ranger]

It's looking like this trough could be the most impressive September trough for the PNW since 2013. However, that trough came at the end of the month. You'd probably have to go back to 2004 to find one this cold that occurred before the last week of the month.

[Dave]

We received a few light showers down here today, but much of it didn't stick.  I just checked and it has all melted.  But at least all of the smoke is gone.

[BLI snowman]

Secret's out. We are actually drier on average than you guys Sept-March.

More Californians moving up= More UHI + More palm trees

[Dave]

You gotta feel for the already battered islands.  It's looking like round 2 is pretty likely for some spots completely devastated by Irma.

 

http://www.nhc.noaa.gov/storm_graphics/AT15/refresh/AL152017_5day_cone_no_line_and_wind+png/025614_5day_cone_no_line_and_wind.png

[TT-SEA]

It's looking like this trough could be the most impressive September trough for the PNW since 2013. However, that trough came at the end of the month. You'd probably have to go back to 2004 to find one this cold that occurred before the last week of the month.

 

We were out of town... but I remember some giddy excitement on here with the Labor Day trough in 2009. 

[Jesse]

We were out of town... but I remember some giddyexcitement here with the Labor Day trough in 2009.

That was 2008. Whether or not PDX's 62/48 on 8/31 will be surpassed with this one, just two and a half weeks later, is yet to be seen!

[Front Ranger]

We were out of town... but I remember some giddy excitement on here with the Labor Day trough in 2009. 

 

Yeah, that one was fairly impressive for how early it was, but not as cold as this one.

[Phil]

You gotta feel for the already battered islands. It's looking like round 2 is pretty likely for some spots completely devastated by Irma.

 

http://www.nhc.noaa.gov/storm_graphics/AT15/refresh/AL152017_5day_cone_no_line_and_wind+png/025614_5day_cone_no_line_and_wind.png

Awful. I think Barbuda is abandoned for the time being.

[BLI snowman]

Yeah, that one was fairly impressive for how early it was, but not as cold as this one.

Late September 2007 was nice.