September 2018 Weather in the Pacific Northwest

[Phil]

A northward shift of Hadley Cells/expansion of the Four Corners high is the likely culprit. Or global cooling, in layman’s terms.

The former. The EPAC Hadley Cell descending branch is, on average, about 10 degrees poleward now compared to 50yrs ago.

[Jesse]

Maybe someone threw their butt out the window.

Possible they mistook it for climo.

[Phil]

[TT-SEA]

Here is some rain porn for the rain-starved... from the Minneapolis NWS.

 

Models in great agreement that this "hot" area will set up from

southern Minnesota into western and north central Wisconsin tonight,

with potential for an average 3 to 5 inches of rain and locally

higher amounts. Could even be little in the way of lightning, but

rainfall rates near 2 inches per hour at times. This could produce

new flash flooding, urban flooding in cities, and new river flooding

in basins that have not been impacted by this week long pattern so

far. Weather Prediction Center has even raised their Day 1 Excessive

Outlook level to HIGH. We are certainly messaging the possibility of

big impacts for this area.

 

Of course, these storms will also track into areas further south

that have been hard by recent rains. Some communities have seen 10

to 15 inches of rain over the past 7 days so ANY additional will

lead to quick runoff and even worse flooding. Rainfall amounts from

northeast Iowa into southwest Wisconsin may only average 1 to 3

inches but again, given how wet it is, it will NOT take much to

cause flash flooding and compound the situation.

 

 

And then followed by this...

 

[Phil]

Sounds heavenly. Rain saved the day here too. We were easily on pace for a 95+/78+ afternoon when a thunderstorm exploded overhead and sent us spiraling down to 77/70 during peak heating. Cloud tops went from

 

Felt like bliss for a few hours after that.

[Geos]

74 for a high today. Not a bad day at all.

 

Edit:

 

18z GFS shifted the action further south.

 

[El_Nina]

A bit hazy today.

[Jesse]

A bit hazy today.

It was pleasant god D**n you!!!

[TT-SEA]

It was pleasant god d**n you!!!

It was.

[TigerWoodsLibido]

A bit hazy today.

In my house for sure. Nice green haze. Pretty sure it's purple diesel right now.

[Phil]

This is interesting. Weak inverse correlation between summer and fall temps in the west.

 

 

That strong positive correlation in NE-Canada is pretty interesting, too. More Baffin Bay vortex this autumn?

[TigerWoodsLibido]

This is interesting. Weak inverse correlation between summer and fall temps in the west.

 

 

That strong positive correlation in NE-Canada is pretty interesting, too. More Baffin Bay vortex this autumn?

Maybe it can be shot over this way.

[El_Nina]

It was pleasant god d**n you!!!

It wasn't bad today. Tomorrow will be back to suckville though.

[El_Nina]

In my house for sure. Nice green haze. Pretty sure it's purple diesel right now.

I usually devote that to a small upstairs bathroom rather than the whole house...

[TT-SEA]

00Z GFS digs the trough early next week deeper than the 12Z run... share the wealth with what is left of Oregon!  

[Esquimalt]

Very wet progression on the 0Z as a 994 MB low approaches from the SW on the 10th day.

[TigerWoodsLibido]

I usually devote that to a small upstairs bathroom rather than the whole house...

Making an exception as I recover from surgery ;-)

[Farmboy]

Very wet progression on the 0Z as a 994 MB low approaches from the SW on the 10th day.

It all looks good on paper, but until it gets within 3 days......

[TigerWoodsLibido]

Very wet progression on the 0Z as a 994 MB low approaches from the SW on the 10th day.

Within 7 days things generally turn dry/boring for the Willamette Valley. But maybe this time it will be different.

[snow_wizard]

Chilly looking pattern on the 0z GFS next week.  That could easily give some of us our first low in the 30s of the season.  It dropped to 45 here last night which felt pretty nippy.

 

Really interesting how we have been stuck in this hot summer pattern for several years now, while spring, autumn, and winter have completely broken away from that since the mega torch a couple of years ago.  I think these hot summers have a lot to do with the ENSO regime shift we have experienced.  A lot of El Nino head fakes in the summer with many years recording the warmest ENSO anomalies in the summer with most years showing significantly colder ENSO anomalies in the winter.  That is an unusual progression historically speaking, and it has become common place in recent years.

[TT-SEA]

The 00Z ECMWF surface maps show a really nice weekend now.     

 

And then rain on Monday... finally some good timing.    Everything seems to come in on weekends this year.   Even in August... 2 of the 4 weekends had rain and clouds here in an otherwise dry month.  

[snow_wizard]

Within 7 days things generally turn dry/boring for the Willamette Valley. But maybe this time it will be different.

 

I would rather get into cold relatively dry troughing like the GFS is showing for a while.  That gives us a shot at some really impressive minus anoms.

[TT-SEA]

I would rather get into cold relatively dry troughing like the GFS is showing for a while.  That gives us a shot at some really impressive minus anoms.

 

Not sure cold anomalies are really needed... like rain is needed to our south.   

[TT-SEA]

Total rain on Monday...

 

[TT-SEA]

Total rain on Tuesday...

 

[TT-SEA]

And total rain on Wednesday...

 

[Deweydog]

I would rather get into cold relatively dry troughing like the GFS is showing for a while. That gives us a shot at some really impressive minus anoms.

Droughtlover!!!

[Deweydog]

Up to a tasty 72 at Larch.

[Geos]

Total rain on Tuesday...

 

 

Like to see it moisten up again. Much warmer this morning at 55. 

[SilverFallsAndrew]

Looks like we could get a little more rain over the next week or two. Certainly no signal for sustained warmth. Sounds good to me. 

[TigerWoodsLibido]

Looks like we could get a little more rain over the next week or two. Certainly no signal for sustained warmth. Sounds good to me.

Hope we do west of I-5 also. Blocked by the coast range.

[Esquimalt]

12Z GFS not looking as wet. The troughs seem toned down relative to the 00Z and 06Z

[TT-SEA]

We finally have an arctic blast showing up by day 7!    So late this year.... but better late than never.   

 

[TigerWoodsLibido]

12Z GFS not looking as wet. The troughs seem toned down relative to the 00Z and 06Z

Looks like a clipper about to drop down in the clown range GFS.

[Esquimalt]

We finally have an arctic blast showing up by day 7! So late this year.... but better late than never.

 

That 500mb pattern is something we could only dream of in January. Of course it has to happen in September lol.

[Geos]

Through 192

 

 

Quite the heck of a cold shot into central BC!

 

 

[Jesse]

Hope we do west of I-5 also. Blocked by the coast range.

The lack of rain the last several months has been caused by a lot more than just the coast range.

[SilverFallsAndrew]

We finally have an arctic blast showing up by day 7!    So late this year.... but better late than never.   

 

 

I bet it all slides east though...

[TT-SEA]

Here it comes!!   The dream is alive.      Flash freeze!  

 

[Geos]

Respectable mountain snows.