October 2017 PNW Discussion Thread

[Jesse]

I've been watching the long range models pretty closely since late summer and the common theme has been a more northern focused cold anomaly and my leading analog (1996) for this winter also points to this.

 

Disclaimer - This is NOT a forecast. 

 

Fair enough!

[ShawniganLake]

Warm this morning, already up to 58F.

Not that warm here. But it did jump from 43 to 52F during the night.

[Timmy]

I've been watching the long range models pretty closely since late summer and the common theme has been a more northern focused cold anomaly and my leading analog (1996) for this winter also points to this.

 

Disclaimer - This is NOT an official forecast.

I love the disclaimer, when I read that it says “ I don’t want blamed when I’m wrong, but I want credit when I’m right”

[Front Ranger]

I've been watching the long range models pretty closely since late summer and the common theme has been a more northern focused cold anomaly and my leading analog (1996) for this winter also points to this.

 

Disclaimer - This is NOT an official forecast.

Some blend of 2007, 1996, 1984, 1966, and 1962 seems like a decent analog group.

[Kayla]

I love the disclaimer, when I read that it says “ I don’t want blamed when I’m wrong, but I want credit when I’m right”

 

You just quoted the weather industry golden standard.

[Kayla]

Some blend of 2007, 1996, 1984, 1966, and 1962 seems like a decent analog group.

 

Agreed.

[TT-SEA]

12z GFS not looking as top-heavy with the block at hour 180 when compared to 06z/00z.

 

Just looks wet now...

 

[Jesse]

Just looks wet now...

 

Axl Rose will be pleased.

[SilverFallsAndrew]

Looks pretty seasonal. 

[ShawniganLake]

Just looks wet now...

 

Both the euro and GFS look similar in that range. Transitioning to a cool and potentially wet pattern

[TT-SEA]

Since the GEM proved itself a little bit with the ridge earlier this week... here is what the 12Z GEM shows for later next week.    Very different pattern...

 

[Jesse]

Looks pretty seasonal.

*Seezinable

[TT-SEA]

Nice improvements on the 12Z ECMWF for Sunday.   Previous runs had been consistently showing a solid marine layer all day... in fact even deepening it during the day as well.

 

But that little system under the ridge appears to be weaker on the 12Z run and it shows sunny skies now except near the water in the morning.  Be nice to have nice weather on both days this weekend.  

[Phil]

That’s only true for 1966-67, and in that case I think OLM north just got lucky with a snowstorm. The other years from the list I think you are talking about didn’t feature a notable north/south gradient to speak of, sans perhaps 1996-97.

 

I haven’t really heard anyone talking about this being a big N-S gradient winter until just now. Of course it’s late October so who is to say if this will even be a big winter for anyone.

Well, 1966-67 wasn't a second year Niña. It followed the very strong El Niño of 1965-66.

 

I'd re-frame it as Niña/-QBO winters having the tendency for stronger jets/tighter gradients, but even then the correlation only holds for moderate/strong Niñas. Weak Niñas seem to open the door to more intraseasonal variability/blocking and solar forcing as well.

[Jesse]

12z Euro is sort of a disappointing run all around.

[TT-SEA]

12z Euro is a sort of disappointing run all around.

 

Sure turns wet later next week!  

[Jesse]

Sure turns wet later next week!  

 

Guts the little system that gave us potential for a somewhat chilly Halloween, then turns rainy but not very cold. Boo.

[TigerWoodsLibido]

Glad of this.  Don't want to start having PV drops too early. I want it in December/January where it's coldest.

[Kayla]

Guts the little system that gave us potential for a somewhat chilly Halloween, then turns rainy but not very cold. Boo.

 

Good news is the EPS looks drier and colder. Ridge doesn't get pinched off.

[Jesse]

Good news is the EPS looks drier and colder. Ridge doesn't get pinched off.

Yeah, I figured the Euro might be showing its general cutoff bias toward days 8-10.

[Kayla]

Yeah, I figured the Euro might be showing its general cutoff bias toward days 8-10.

 

Yeah, wouldn't be the first time. The EPS control run actually looks really good days 10-15.

 

 

[Phil]

That's one heck of a -EPO/Alaskan ridge on the 12z EPS.

 

The entire country west of the Appalachians is colder than average, verbatim. Coldest anomalies of the entire NH are over Montana and North Dakota.

[Phil]

WPAC warm pool is getting destroyed. It's the primary heat source for the extratropical NH (especially during winter), so I'm anticipating some very cold air to develop in the high latitudes in about a month, should the low frequency degradation of the last few months continue.

 

[Geos]

Yeah, wouldn't be the first time. The EPS control run actually looks really good days 10-15.

 

Screen Shot 2017-10-25 at 2.19.47 PM.png

Screen Shot 2017-10-25 at 2.14.40 PM.png

 

That would be epic. Early November snowfall here we come!

[Geos]

Colder than normal waters from Ecuador straight across to Papua New Guinea now.

 

[Phil]

Here comes the MJO-driven WWB. This might be enough to force a downwelling oceanic Kelvin Wave, in which case the Niña has probably peaked, structurally speaking (similar to last year's early peak). Still quite uncertain, though.

 

http://www.atmos.albany.edu/student/ventrice/real_time/timeLon/u.anom.30.5S-5N.gif

[TT-SEA]

Here comes the MJO-driven WWB. This might be enough to force a downwelling oceanic Kelvin Wave, in which case the Niña has probably peaked, similar to last year's early peak. Still quite uncertain, though.

 

http://www.atmos.albany.edu/student/ventrice/real_time/timeLon/u.anom.30.5S-5N.gif

 

It was quite the Nina!   Time for it go now.  

[TT-SEA]

Pretty morning...

 

 

 

Sure turned ugly today... drizzle storm 2017.

 

[Phil]

It was quite the Nina! Time for it go now.

Interesting how we went from La Niña conditions last autumn, to El Niño conditions during the Spring, to La Niña conditions again this autumn, to perhaps something else within 3-4 months.

 

These higher frequency vascillations in the ENSO system just scream low frequency regime change. The last two periods with such behavior were the late 1970s/early 1980s (great Pacific climate shift) and the late 1950s/early 1960s, which flipped the AMO and brought on the blockiest stretch of winters since the LIA.

[Geos]

Up to 56 after a low of 41 this morning. Have had a few sprinkles today and now a little drizzle. 

[TigerWoodsLibido]

Clouds starting to creep in here. I doubt the precip makes it this far south.

[Phil]

One thing working against an OKW response is the higher frequency nature of this MJO/CCKW/what have you. Might not be enough time for a big slosh as easterlies return in a few weeks.

[Front Ranger]

Sure turned ugly today... drizzle storm 2017.

 

 

I think it's beautiful.

[TigerWoodsLibido]

Sneak peak to this winter?

Hopefully not. I would enjoy the first ever blizzard warning for the Willamette Valley.

[Gradient Keeper]

18z sure looks different from it's brethren.

Yeah. AK Block gets pinched off. You can't even wishcast this run if you tried.

 

Onto 00z GFS!

Begins in 4 hours 9 minutes

[Jesse]

We seem to be stuck in a rut right now where everything trends warmer as it gets closer.

[TT-SEA]

We seem to be stuck in a rut right now where everything trends warmer as it gets closer.

 

Seems to go in cycles.  

[Jesse]

Seems to go in cycles.

I’ve noticed the same thing.

[Jesse]

Ensembles look gooder.

[TigerWoodsLibido]

Everyone in the PNW will get something this year. I just don't think it'll happen til mid-December