September 2019 Weather Discussion for the PNW

[Front Ranger]

NWS tweeted that downtown Portland only reached 49 today. Previous earliest sub-50 max was October 12, 1881. Crazy.

Wow. I'd say this cold snap has exceeded expectations for highs - now let's see how it performs for lows.

[wx_statman]

Thanks. She was born at 1:32pm today. Wasn’t due till October 18th, so be prepared. It was a long tough pregnancy for my wife and the doctors finally recommended enough was enough. Her initials coincide with my favourite meteorological index. The AMM. Mom and babe are resting comfortably

 

Wow. I'm glad to hear the baby is OK (and mom). We have been fortunate so far...

[wx_statman]

Congrats brother!

 

So..pattern change on 10/13?

 

Thank you! 

 

Nothing would surprise me at this point...

[wx_statman]

Wow. I'd say this cold snap has exceeded expectations for highs - now let's see how it performs for lows.

 

One day earlier would have been nice. Tuesday might be in the 30s but of course it's 10/1. Has been a really long time since a low in the 30s in September. 

[Phil]

[SilverFallsAndrew]

Or (for a wishcasty-optimistic possibility) maybe, similarly to how the Jan 2013 SSW/inset EW/RWB cycle changed gears to produce the evolution into that multi-year +PMM/+TNH/broad IPWP from 2014-18, perhaps the event last winter also marked the inception of a new quasi-stable IPWP/WB structure with a backcycle that is more favorable for PNW winters.

 

We've had some decent winters since January 2013. 

[Deweydog]

I have a feeling that moving forward we’ll see some good winters, some bad.

[Jesse]

One day earlier would have been nice. Tuesday might be in the 30s but of course it's 10/1. Has been a really long time since a low in the 30s in September.

There’s an outside chance they could do it tonight. They only have ten degrees to fall. But yeah it’s hard to picture with all of the cloud cover and light rain around this evening.

[Phil]

We've had some decent winters since January 2013.

Well, 2014-18 was the most consistently ridgy period for the PNW @ 500mb since (at least) 1860s according to NCEP/NCAR reanalysis on ESRL. This is true even after detrending global geopotential heights.

[snow_wizard]

There’s an outside chance they could do it tonight. They only have ten degrees to fall. But yeah it’s hard to picture with all of the cloud cover and light rain around this evening.

 

Maybe an 11:59 pm low tomorrow?  Even at that 30s by midnight might be tough.

[Phil]

As for ENSO..here comes the downwelling wave.

 

[snow_wizard]

Dramatic cooling along the entire Pacific rim from South AK to Southern CA over the past 7 days.  Most of the cooling off of Vancouver Island happened in the last day.

 

 

[TigerWoodsLibido]

The d-band has filled in even more and is now encompassing the entire southern half of the valley.

[Phil]

Dramatic cooling along the entire Pacific rim from South AK to Southern CA over the past 7 days. Most of the cooling off of Vancouver Island happened in the last day.

Funny thing is, the daily PDO numbers have actually increased slightly since Thursday, thanks to the cooling over the central Pacific in conjunction with the warming in the GOA.

 

[Jesse]

Maybe an 11:59 pm low tomorrow? Even at that 30s by midnight might be tough.

Yeah that would be pretty much unheard of this early.

[snow_wizard]

Funny thing is, the daily PDO numbers have actually increased slightly since Thursday, thanks to the cooling over the central Pacific in conjunction with the warming in the GOA.

 

 

We'll see how it all shakes out after the restructuring is finished.

[Jesse]

[Front Ranger]

One day earlier would have been nice. Tuesday might be in the 30s but of course it's 10/1. Has been a really long time since a low in the 30s in September.

True, but still could have some benchmark historic lows on 10/1.

 

I would not count on PDX for such things, of course.

[snow_wizard]

As for ENSO..here comes the downwelling wave.

 

 

All in all I still see no way we will end up with an official Nino this winter.  We are starting out totally wrong for that.  A neutral winter is the right call I think.  The 160W to 160E OLR has flipped to positive so that is even more of a burden for any Nino that wants to develop.

[SilverFallsAndrew]

-11 departures at SLE and PDX today.

[SilverFallsAndrew]

The 2014-18 period may have been crazy ridgy, but it had some good winters in that period. 

[TacomaWaWx]

The 2014-18 period may have been crazy ridgy, but it had some good winters in that period.

13-14, 16-17, 17-18. All 3 were good.

[snow_wizard]

13-14, 16-17, 17-18. All 3 were good.

 

Very true.  It's like it's been finding a way to get cold regardless.  Actually beginning with 2006-07 almost every winter has managed some kind of respectable cold.  With just a few exceptions.

[Jesse]

Looks like there is a pretty sharp line of clearing to the north of the deformation band, moving south. It has reached Kelso now. They are reporting clear skies and 45.

 

Meanwhile the east winds have kicked up a notch here and at PDX it appears.

[GHweatherChris]

PDO is a result.

[Phil]

[snow_wizard]

I was just looking through my records for late last winter and I had forgotten about the crazy high min temp of 59 I recorded in March.  That was by far the highest minimum anywhere near that early ever recorded in this general area.  You contrast that with what's happening now and what happened just before that and you have one crazy year!

[snow_wizard]

I was just thinking that, haha. I’m just posting a lot because it’s Sunday night ahead of a brutal week where I won’t be able to post much at all, and I happen to disagree with some of Jim’s posts lately.

 

I don’t love him any less than I did before.

 

I think we are in a pretty crazy situation right now where the rule book is being rewritten.  I'm fully aware my thoughts about ENSO right now could be wrong.  It's going to be a learning experience for sure!

[snow_wizard]

Looks like there is a pretty sharp line of clearing to the north of the deformation band, moving south. It has reached Kelso now. They are reporting clear skies and 45.

 

Meanwhile the east winds have kicked up a notch here and at PDX it appears.

 

The breeze has quit here.  Still some debris clouds floating over at times, but I'm getting some good breaks.  Currently 48.

[Deweydog]

PDO is a result.

Of poor oral hygiene?

[Phil]

All in all I still see no way we will end up with an official Nino this winter. We are starting out totally wrong for that. A neutral winter is the right call I think. The 160W to 160E OLR has flipped to positive so that is even more of a burden for any Nino that wants to develop.

OLR/VP200 anomalies look more niño-ish than niña-ish any way you slice it, man. I agree it’ll be tough to meet the “official” ONI criteria, but I’m not sure it matters re: the seasonal progression.

 

Warm neutral or weak west based/modoki niño is a fairly safe bet at this point, IMO. At this point I would argue that an actual El Niño is more likely than even a cold neutral outcome.

[TacomaWaWx]

Sitting at 51 degrees at 8:15pm. Needs to get down to 41 to be a new record here, hopeful that we see some upper 30s. Tomorrow night might end up being the cooler night but I’m rooting for a night in the 30s in September!

[SilverFallsAndrew]

Up to 50 at PDX.

[GHweatherChris]

Of poor oral hygiene?

You have that on a tshirt don't you?

[Phil]

You have to be careful with OLR. There is a major subsidence event ongoing, yes, but it’s actually centered over the Maritime Continent, which is associated with a +ENSO type circulation.

 

 

In fact this is quite extreme..in the unfiltered phase diagrams it calculates to a strong phase 8/1 type (-VP anomalies focused in the WHEM, away from the IPWP).

[Deweydog]

You have that on a tshirt don't you?

There’s a reason why Flatiron didn’t brush his teeth between 1998 and 2001.

[Jesse]

[Blizzard777]

Hit 53 just briefly. Looks like it’s a 53/47 day the coolest I have on record for September. Suns come out a bit nice evening.

55/45 apparently sun must of made an appearance as temp rose to 55 @ 5:11pm

[ShawniganLake]

55 here in Duncan. The breeze is dying down but still pretty cloudy.

[Dave]

Probably an unpopular opinion here, but I'm siding with Tim. It should be relatively warm and mostly dry this time of year. All of the mountain snow will melt out before winter. I'm done with this cold and rainy white. It shouldn't happen until November.