November 2017 PNW Discussion Thread

[wx_statman]

It was a little frustrating driving home in the rain just now.

 

Then I remembered I was coming home from a Halloween party.

 

And it looks like I was wrong. Snowing in Seattle again!

[ShawniganLake]

12z getting an early start today! Has to be a good sign...

It’s always a good sign when timing moves up in the models. We don’t want to see things being delayed.

[Phil]

Oh my!! Thank you that clears up everything!!!

Keep a close eye on the standardized 50mb zonal wind anomaly over the equatorial WPAC/Indo domain. It really matters for the circulation across the NPAC. We still have westerlies ongoing at/below 50mb, which via thermal wind/tropopause coupling to Hadley/Walker system/eliassen-palm conuits, are significantly affecting the NPAC wavetrain (poleward anticyclones, compromised EHEM/Indo cell network).

 

When this regime flips (probably sometime during the first half of this winter), we'll start depositing a lot more easterly momentum above the zero wind line and will completely reverse the thermals capping the WPAC/Indo source from where this Rossby Wave train is eminating from, sustaining the backloop to 10S-20N lower tropospheric U/V wind ratio.

 

In other words, the tropical forcing/NPAC circulation will likely change in a major way towards the end of the year, and/or sometime in early 2018. Perhaps into a state more reminiscent of 2007/08, or perhaps into something more 1960s-esque. It all depends on when the change occurs, and the structure of the NAM/PV at the time of MJO genesis in the IO.

[Geos]

Moderate snow once again, temp 33.

 

Sounds and looks like you got a couple inches up there.

 

A light snow is building back up here. Roads are now slushy, but the temp is still 32.

[wx_statman]

Snow not as widespread in W. WA today, but very widespread in E. WA. Even snowing in Tri-Cities this morning. 

 

Super rare for them this early. Only measurable snowfalls I can find pre-11/6 were in 1971, 1973, and 1991. 

[seattleweatherguy]

Light snow or wintry mix here

[Geos]

I'm surprised it's not colder along the Hood Canal. Usually if it's snowing here it's cold enough to snow there too.

 

Tiger Mountain pass getting a good coating.

 

[Jesse]

Super rare for them this early. Only measurable snowfalls I can find pre-11/6 were in 1971, 1973, and 1991.

The next place to watch for early snowfall will be the eastern Gorge and Hood River valley toward the middle of the week. Overrunning event starting to look possible.

[wx_statman]

Really incredible to see two measurable snowfalls in the Seattle area by 11/5. I think this is the first time that's happened since 1973. SEA reported snowfall on 11/3, 11/4, and again overnight on 11/5-11/6 that year. Very similar progression to this year. 

[TigerWoodsLibido]

Currently 48 here. Looks like we will hit somewhere close to 52. If we get any clearing into tomorrow it'll probly drop to the upper 30s with fog developing. Might be slow to clear tomorrow.

[SilverFallsAndrew]

Next couple of weeks look pretty climo. 

[wx_statman]

The next place to watch for early snowfall will be the eastern Gorge and Hood River valley toward the middle of the week. Overrunning event starting to look possible.

 

Might as well keep the party train rolling. 

[SilverFallsAndrew]

http://old.wetterzentrale.de/pics/MT8_Portland_Oregon_USA_ens.png

[TigerWoodsLibido]

Next couple of weeks look pretty climo.

There will be another blast around Thanksgiving. Black Friday snowstorm maybe?

[umadbro]

Get that basin good and cold.

[MossMan]

Sounds and looks like you got a couple inches up there.

 

A light snow is building back up here. Roads are now slushy, but the temp is still 32.

I’m still stuck at a 1/2” but still moderate snow. The pic I took was about 1 mile down the road at just the slightest higher elevation...all it takes with this marginal setup. About 2” there.

[Jesse]

Next couple of weeks look pretty climo.

Yeah you beat me 2 it. Ensembles have slowly trended from being below average to near average. Probably not a terrible thing in the bigger picture.

[umadbro]

There will be another blast around Thanksgiving. Black Friday snowstorm maybe?

I thought you said that the current pattern was locked in?

[SilverFallsAndrew]

Yeah you beat me 2 it. Ensembles have slowly trended from being below average to near average. Probably not a terrible thing in the bigger picture.

 

Yeah I don't think its a bad thing at all. Get those rainfall totals up

[ShawniganLake]

There will be another blast around Thanksgiving. Black Friday snowstorm maybe?

I have a feeling we will be waiting till December now.

[TT-SEA]

Really incredible to see two measurable snowfalls in the Seattle area by 11/5. I think this is the first time that's happened since 1973. SEA reported snowfall on 11/3, 11/4, and again overnight on 11/5-11/6 that year. Very similar progression to this year. 

 

[Phil]

Big time wave amplification might be in the pipeline for mid/late December. Of what nature, I'm not sure yet.

[Jesse]

I have a feeling we will be waiting till December now.

I’ve been feeling that way ever since this cool snap first showed up.

[HighlandExperience]

I didn’t realize that 71-72 was such a big snow year. Would love to see that.

[snow_wizard]

Looks like a big slug of moisture is organizing in the South Sound and heading north.  Could be a good round of snowfall for many.  Currently light snow and 34 degrees here.  Nothing has really been able to stick yet, but this incoming moisture may change that.

[Phil]

There's that Scandi ridge/Eurasian dipole again. Might be time to que the jaws music.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/B5AE8D3F-D4A0-4611-9445-744B998E1222_zpsadeeodb6.png

[snow_wizard]

I didn’t realize that 71-72 was such a big snow year. Would love to see that.

 

1971-72 was fantastic.  That is the first winter I really remember as a kid.

[Blizzard777]

Now it’s sleeting in Federal Way

[snow_wizard]

There's that Scandi ridge/Eurasian dipole again. Might be time to que the jaws music.

 

 

I'm really liking what I'm seeing thus far.  It will be interesting to see what happens when the QBO flip happens at 50mb.  Perhaps the mean pattern will already be firmly set by then.  At any rate I have always (the last several weeks) targeted December as being a sure bet for snow this winter, with January being the huge wildcard for potentially being epic.

[Guest happ]

Next couple of weeks look pretty climo. 

 

Which means bad news for California 

[snow_wizard]

Now it’s sleeting in Federal Way

 

That is really surprising.  I wonder if it might be convective / ice pellets.  Pretty important difference there.  If it's convective things might really get fun.

[SilverFallsAndrew]

I will be out of state about the 14-22 or so of December...Pencil that in for some snow...

[ShawniganLake]

1971-72 was fantastic. That is the first winter I really remember as a kid.

Huge winter across southern BC too.

[snow_wizard]

Which means bad news for California 

 

He only meas climo for observed weather here.  The setup over the NE Pacific will be pretty abnormal.

[snow_wizard]

Huge winter across southern BC too.

 

1970-71  was a huge one up there too.  Really huge in fact.

[ShawniganLake]

There's that Scandi ridge/Eurasian dipole again. Might be time to que the jaws music.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/B5AE8D3F-D4A0-4611-9445-744B998E1222_zpsadeeodb6.png

I’m going to need a reminder why we are queuing the jaws music?

[TT-SEA]

Not sure we will stay cold enough even if the precip is able to make it this far north.

 

My temp has rose 2 degrees the past hour and a half to 34. Still have light snow falling though.

 

Yeah... warming up here too.    

[SilverFallsAndrew]

1970-71  was a huge one up there too.  Really huge in fact.

 

1970-71 was one of the snowiest winters at Salem, and also a top 5 snowiest winter up here in the foothills (1938-present). 

[BLI snowman]

Nice mild day down here. Hoping we break 50 again.

[snow_wizard]

Not sure we will stay cold enough even if the precip is able to make it this far north.

 

My temp has rose 2 degrees the past hour and a half to 34. Still have light snow falling though.

 

My temp here has been rock steady for the past two hours.