September 2018 Weather in the Pacific Northwest

[Jesse]

Seems to me we had a pretty normal amount of cyclonic stuff this summer, we just tended to be either on the rebound side of waves sliding SE to our east or under BSWF thanks to a fairly persistent but rather muted four corners high. A stronger and more amplified high would have meant more mid level moisture, more convection, more fun.

Stronger and more amplified don’t always necessarily go together. A stout, low amplitude 4CH can be a pretty tough nut to crack, as we have seen. A more amplified 4CH would be in part a result of a more amplified wavetrain in general. Ie it is getting squeezed more by deep, amplified troughs on either side.

 

Broad, low amplitude ridges seem to promote a much more stable pattern. Consistently warm with little in the way of swings, and a northward shifted mean jet position. We have seen an awful lot of that lately. Lot of chicken versus egg stuff there of course but those have been my observations.

[Deweydog]

Stronger and more amplified don’t always necessarily go together. A stout, low amplitude 4CH can be a pretty tough nut to crack, as we have seen. A more amplified 4CH would be in part a result of a more amplified wavetrain in general. Ie it is getting squeezed more by deep, amplified troughs on either side.

 

Broad, low amplitude ridges seem to promote a much more stable pattern. Consistently warm with little in the way of swings, and a northward shifted mean jet position. We have seen an awful lot of that lately. Lot of chicken versus egg stuff there of course but those have been my observations.

The summer "jet" is pretty much non-existent. Calling it shifted north or south is kind of a tough generalization to make. As for convection, it's pretty much about mid level moisture transport thanks to a little tap into the monsoon or some manner of ULL cyclonic action, particularly with some diffluence. We didn't have much of either.

[Jesse]

The summer "jet" is pretty much non-existent. Calling it shifted north or south is kind of a tough generalization to make. As for convection, it's pretty much about mid level moisture transport thanks to a little tap into the monsoon or some manner of ULL cyclonic action, particularly with some diffluence. We didn't have much of either.

I get the general mechanics of summer convection here. My comment was more about your assertion that a more amplified 4CH means a stronger one. I think it can be the opposite in many cases. Depending on how you are defining strong of course. If it is by overall stability/immovability don’t think there is much of a contest.

[BLI snowman]

The summer "jet" is pretty much non-existent. Calling it shifted north or south is kind of a tough generalization to make. As for convection, it's pretty much about mid level moisture transport thanks to a little tap into the monsoon or some manner of ULL cyclonic action, particularly with some diffluence. We didn't have much of either.

I don't agree that we've seen a normal amount of 500mb energy this summer. What we have seen has been weak and of the meandering/rudderless variety, which while typical of summer to an extent, has been especially true of the past two years.

 

There's a reason why our westside summer convection will often be affiliated with pattern crashes and sharp marine pushes. We just haven't seen much of any of that, and there's been meager monsoonal tap to boot.

[MossMan]

The sun!

[Deweydog]

I don't agree that we've seen a normal amount of 500mb energy this summer. What we have seen has been weak and of the meandering/rudderless variety, which while typical of summer to an extent, has been especially true of the past two years.

 

There's a reason why our westside summer convection will often be affiliated with pattern crashes and sharp marine pushes. We just haven't seen much of any of that, and there's been meager monsoonal tap to boot.

Meandering and rudderless can describe most of our traditional summer patterns. This one had its fair share of 500mb cyclonic action but we generally didn't see a great deal of amplitude which is traditionally the precursor to ULL reversals/west side convective outbreaks.

 

It was a hot, dusty and smoky summer, yes, but it was also pretty unremarkable.

[BLI snowman]

Meandering and rudderless can describe most of our traditional summer patterns. This one had its fair share of 500mb cyclonic action but we generally didn't see a great deal of amplitude which is traditionally the precursor to ULL reversals/west side convective outbreaks.

 

It was a hot, dusty and smoky summer, yes, but it was also pretty unremarkable.

 

Unremarkable and monotonous is exactly how it's been portrayed. The nuance is more with the degree of its monotony, which has been very impressive even by modern summer standards. And this coming hot (LOL!) on the heels of a very similar summer last year.

[Farmboy]

Been some very bizarre tracks for Florence coming out on the models today.

[Geos]

The 00z EPS is projecting a *very* familiar pattern in the extended range.

 

D10-15:

 

 

Why can't we put that vortex over the NE Pacific for a change?

[Geos]

0.12" of rain last night. Saw a few sprinkles during the day but nothing measurable. Few peaks of sun, but they haven't lasted long.

[Jesse]

Amazing what a consistent middle finger high temps have been lately.

[MossMan]

Amazing what a consistent middle finger high temps have been lately.

Warmed up to a toasty 65 here!

[Jesse]

[MossMan]

[Frontal Snowsquall]

FWIW, there is a relatively tight cluster near Wilmington on the 12z EPS. Some extremely strong solutions in there, which makes the possibility of a stall or “loop” all the more disturbing.

 

Been some very bizarre tracks for Florence coming out on the models today.

There's definitely been a slight shift North with the track today. We should get a better idea by Monday. The possibility of it being a major hurricane and then stalling is the biggest concern IMHO.

 

http://oi67.tinypic.com/2q8boxw.jpg

 

Matthew Ferreira | MassachusettsWx@MassachusettsWx

 

Quite a shift north today with my thoughts..aligns with modeling..

 

https://mobile.twitter.com/MassachusettsWx/status/1038548229061791745

[Phil]

Forecasting a Category 5 at landfall 5+ days out is pretty reckless and irresponsible IMO. Not that it won’t happen (it easily could), but nothing remotely close to a Cat5 has struck NC since Hazel in 1954 (Cat4).

[SilverFallsAndrew]

I'd bet pretty confidently Florence curves before a direct landfall.

[weatherfan2012]

Forecasting a Category 5 at landfall 5+ days out is pretty reckless and irresponsible IMO. Not that it won’t happen (it easily could), but nothing remotely close to a Cat5 has struck NC since Hazel in 1954 (Cat4).

Hazel was also a phase  It also brought parts of our region 80 to 100 mail wind gust as it past just west because it was moving very fast it was still a very strong system even in our region.Had to of been quite a wild weather event to have experience.

[MossMan]

I'd bet pretty confidently Florence curves before a direct landfall.

Yep, that is what I am thinking as well. Jim Cantore will be quite sad.

[MossMan]

Lovely partly cloudy evening, had dinner outside while my daughter and dogs played in the yard. Just as we finished and cleaned up the rain started pouring down again. Great timing!

[TT-SEA]

Lovely partly cloudy evening, had dinner outside while my daughter and dogs played in the yard. Just as we finished and cleaned up the rain started pouring down again. Great timing!

Yep... we are back to finding some time during each day when its not raining for maybe the next week. It will keep coming in waves. It barely has a chance to dry out in between. The Pacific NorthWET!!

[El_Nina]

I just caught up on reading all the posts from the 6th through today. Another trough got gutted, then to top it all off, someone remarkably said this summer was pretty unremarkable despite being the most remarkable in the sense of no remarkable record heat despite being remarkably hot.

[El_Nina]

0.06" this morning.

[El_Nina]

I think we could see another 2 or 3 named storms over the next 2 weeks. Helene should be named before the end of the weekend, I suspect.

Florence will be a close call, but it’s not outrageous to expect a US landfall given the latitude of the anticyclone and Gordon’s remnants offering a weakness under said ridge. Best analog might be the 1933 Chesapeake Potomac hurricane? That was a weaker storm but the regional pattern was very similar.

Nailed it again!

[SilverFallsAndrew]

0.00" here the past 24 hours. 

[MossMan]

0.00" here the past 24 hours.

Still raining here...wish I could send some down to you.

[GHweatherChris]

What happened to the Fox 12 Weather Blog?

[TT-SEA]

What happened to the Fox 12 Weather Blog?

 

 

https://fox12weather.wordpress.com/

[TT-SEA]

The most recent post on there by Mark is interesting... running just slightly drier than normal for early September down there.  

 

 

A “1000 hour fuel” refers to large fuels (8″ diameter or larger).  First look at an “average” year…the gray line.  In the north Cascades of Oregon fuels in a “typical year” are driest just after mid-August and then gradually moisten up through September and October.  The red line is the driest the fuel has ever been (on any one date) through the period of record.The yellow line is last year; see how that dry east wind period around Labor Day kept fire danger extremely high until the 16th of September?  The Eagle Creek Fire blew up during this time and there were other huge fires burning across the Willamette/Umpqua National Forests.  You can see the season-ending rain event the following week as many inches of rain fell in the forest; a somewhat miraculous event for this time of year.  Also note the record minimum fuel moisture was set a few times last year, including much of early September.  This year we seem to have “bottomed-out” around the 20th of August, setting a few new “record dry” days just ahead of that time.  Showers and cool weather moistened things up the last week of August and earlier this week so right now we’re running just slightly drier than average for early September.  Hopefully it all makes sense, of course you can click on the image for a larger view.

 

[GHweatherChris]

https://fox12weather.wordpress.com/

Weird, when I go through my usual link it just takes me to the KPTV weather page and when you click the blog link there it doesn't work either, at least for me.

[El_Nina]

The most recent post on there by Mark is interesting... running just slightly drier than normal for early September down there.  

 

 

A “1000 hour fuel” refers to large fuels (8″ diameter or larger).  First look at an “average” year…the gray line.  In the north Cascades of Oregon fuels in a “typical year” are driest just after mid-August and then gradually moisten up through September and October.  The red line is the driest the fuel has ever been (on any one date) through the period of record.The yellow line is last year; see how that dry east wind period around Labor Day kept fire danger extremely high until the 16th of September?  The Eagle Creek Fire blew up during this time and there were other huge fires burning across the Willamette/Umpqua National Forests.  You can see the season-ending rain event the following week as many inches of rain fell in the forest; a somewhat miraculous event for this time of year.  Also note the record minimum fuel moisture was set a few times last year, including much of early September.  This year we seem to have “bottomed-out” around the 20th of August, setting a few new “record dry” days just ahead of that time.  Showers and cool weather moistened things up the last week of August and earlier this week so right now we’re running just slightly drier than average for early September.  Hopefully it all makes sense, of course you can click on the image for a larger view.

 

You should make sure to specify that the fuel moisture is slightly drier than normal, otherwise you seem like you're actually claiming we've had close to a normal amount of rain lately.

[TT-SEA]

You should make sure to specify that the fuel moisture is slightly drier than normal, otherwise you seem like you're actually claiming we've had close to a normal amount of rain lately.

 

 

Well that does indicate tree stress.

 

Here are Mark's thoughts... looks like summer ended abruptly on 8/22 and summer was dry but nothing too unusual.    

 

MY SUMMER 2018 THOUGHTS

• Weather was consistently warm to hot with few big swings toward extreme heat or cool.
• But we didn’t break a single daily record high temperature in Portland!  Just one tie (95 on June 20th).  We only hit 100 once (July 15th), which is amazing considering it was the 2nd hottest summer on record.
• Warm nights:  2 new record warm lows (June 12 & Aug 10) plus 3 tied record warm lows
• Less morning cloud cover (marine air) than normal.  Seems like late July to mid August we hardly woke up to low clouds.
• Summer “ended” somewhat abruptly after the 22nd of August.  Of course it didn’t really end but the heat suddenly disappeared.
• Nelsen Pool Index: My above-ground pool peaked out at 85 degrees in late July and again during the hot spell in early August (same temp as last year).  But it has been very chilly and not really usable since that sudden change the last week of August.  Last year we were able to use it until the fire ashfall finished things off around September 4th.  Again, summer seems to have more abruptly “ended” this year.
• We were dry, but nothing too unusual.  The very unusual part is the 1.5 month dry spell BEFORE SUMMER EVEN STARTED on June 1st!  That’s what has put us into a drought sit

[El_Nina]

Well that does indicate tree stress.

 

Here are Mark's thoughts... looks like summer ended abruptly on 8/22 and summer was dry but nothing too unusual.    

 

MY SUMMER 2018 THOUGHTS

 

• Weather was consistently warm to hot with few big swings toward extreme heat or cool.
• But we didn’t break a single daily record high temperature in Portland!  Just one tie (95 on June 20th).  We only hit 100 once (July 15th), which is amazing considering it was the 2nd hottest summer on record.
• Warm nights:  2 new record warm lows (June 12 & Aug 10) plus 3 tied record warm lows
• Less morning cloud cover (marine air) than normal.  Seems like late July to mid August we hardly woke up to low clouds.
• Summer “ended” somewhat abruptly after the 22nd of August.  Of course it didn’t really end but the heat suddenly disappeared.
• Nelsen Pool Index: My above-ground pool peaked out at 85 degrees in late July and again during the hot spell in early August (same temp as last year).  But it has been very chilly and not really usable since that sudden change the last week of August.  Last year we were able to use it until the fire ashfall finished things off around September 4th.  Again, summer seems to have more abruptly “ended” this year.
• We were dry, but nothing too unusual.  The very unusual part is the 1.5 month dry spell BEFORE SUMMER EVEN STARTED on June 1st!  That’s what has put us into a drought sit

Read after the second bolded part.

[MossMan]

 

 

Well that does indicate tree stress.

 

Here are Mark's thoughts... looks like summer ended abruptly on 8/22 and summer was dry but nothing too unusual.

 

MY SUMMER 2018 THOUGHTS

• Weather was consistently warm to hot with few big swings toward extreme heat or cool.
• But we didn’t break a single daily record high temperature in Portland! Just one tie (95 on June 20th). We only hit 100 once (July 15th), which is amazing considering it was the 2nd hottest summer on record.
• Warm nights: 2 new record warm lows (June 12 & Aug 10) plus 3 tied record warm lows
• Less morning cloud cover (marine air) than normal. Seems like late July to mid August we hardly woke up to low clouds.
• Summer “ended” somewhat abruptly after the 22nd of August. Of course it didn’t really end but the heat suddenly disappeared.
• Nelsen Pool Index: My above-ground pool peaked out at 85 degrees in late July and again during the hot spell in early August (same temp as last year). But it has been very chilly and not really usable since that sudden change the last week of August. Last year we were able to use it until the fire ashfall finished things off around September 4th. Again, summer seems to have more abruptly “ended” this year.
• We were dry, but nothing too unusual. The very unusual part is the 1.5 month dry spell BEFORE SUMMER EVEN STARTED on June 1st! That’s what has put us into a drought sit

Yep...nothing too notable about this summer. No extremes. Was hoping to see a day or two of triple digits but we never got much above 90 this entire season.

[ShawniganLake]

The length of the dry season outside of the central cascade foothills was highly unusual.

[TT-SEA]

Read after the second bolded part.

 

 

Yeah... there was a 6-week dry period.    Nothing too unusual since then.     

 

And the moisture level down there is just slightly drier than normal for this point in the year per the graph above that.    

[MR.SNOWMIZER]

4000 miles of road and 2 weeks and by far the worst road section i have ever seen is from Ellensburg to auburn. 1 trip and your car will need an alignment.

[TT-SEA]

The length of the dry season outside of the central cascade foothills was highly unusual.

 

 

Yes... the late April and May period extended the season for much of the region.   

 

For the area from Mt. Vernon to Issaquah eastward to the Cascades (i.e central and northern Cascade foothills) the dry season was pretty clearly defined this year from July 3 - September 7.     That assumes we see widespread 1-2 inches of rain in this area over the next week which is almost a given.    So the dry season here was just over 2 months which is very typical.  

[ShawniganLake]

Yeah... there was a 6-week dry period. Nothing too unusual since then.

 

And the moisture level down there is just slightly drier than normal for this point in the year per the graph above that.

“It was the second hottest summer on record”

 

If we had the second wettest summer on record, you would consider that unusual, I think.

[TT-SEA]

4000 miles of road and 2 weeks and by far the worst road section i have ever seen is from Ellensburg to auburn. 1 trip and your car will need an alignment.

 

 

They are prepping I-90 from west of Snoquamie Pass to Issaquah in preparation for a re-paving.   It has gotten really bad and now they have made it temporarily worse.   I cannot wait until its all done!