October 2017 PNW Discussion Thread

[wx_statman]

Wow!

 

I really can't believe how the models are shaping up for the possible cold snap in early November.  This could rival 1935, but just a few days later.  As I mentioned last night major cold snaps beginning in early November are pretty much unheard of.  The best comparisons are probably from late October.  That timing is pretty crucial, because the late October cold snaps in neutral or cold ENSO seasons always lead to something good during the winter...often VERY good.

1973 comes to mind. You’re right that it seems like we get hit more often around Halloween than we do even a few days later.

[Gradient Keeper]

This is actually one of the coldest places tonight...at least according to the observations from the major stations.  Currently 44.

60.9 here with east wind 25-35mph. Mixing, mixing, mixing!

[Gradient Keeper]

10/26/17 10:08 PM 00z ECMWF

Begins.... in 37 minutes

 

Hope to continue the promising runs. Let's dig that arctic trough down right over us.

 

Feel free to play along(You may need to refresh pages)

Northwest view(850mb Temps) - http://www.tropicaltidbits.com/analysis/models/?model=ecmwf&region=nwus&pkg=mslp_pcpn_frzn&runtime=2016112912&fh=0&xpos=0&ypos=197

North American view(500mb Heights, MSLP) - http://www.tropicaltidbits.com/analysis/models/?model=ecmwf&region=namer&pkg=mslp_pcpn_frzn&runtime=2016112912&fh=0&xpos=0&ypos=197

North Pacific view(500mb Heights, MSLP) - http://www.tropicaltidbits.com/analysis/models/?model=ecmwf&region=npac&pkg=mslp_pcpn_frzn&runtime=2016112912&fh=0&xpos=0&ypos=197

Alaska view(850mb Temps) - http://www.tropicaltidbits.com/analysis/models/?model=ecmwf&region=ak&pkg=T850&runtime=2016112912&fh=0

Pivotal Weather 500mb Height Anomalies - http://www.pivotalweather.com/model.php?m=ecmwf&p=500h_anom&rh=2017102600&fh=0&r=na&dpdt=

 

[TigerWoodsLibido]

00z GFS Much cooler run. 522 thickness down to Olympia, 518 Bellingham. Day 8 - 500mb. Awfully close Just need the trough to dig another 200 miles to the south-southwest. It's the closest run yet to a really cold air mass dropping south over us for early November. Snow on this run throughout eastern Washington/Columbia Basin especially north of Pasco. Real close to a backdoor shot via the Gorge on this run. I think it's just exciting enough to see this possibility on most models and it's not even November. Perhaps we could see something similar to the modified blast and big east wind storm comparable to the Veteran's Day event back in 2014.

Just bring that Low a little further south about 150 miles and the WV is in business

[Phil]

Brrr..

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/066F3028-04BB-4CCE-882F-6805D8F0856C_zpsf8mwbdqr.png

[stuffradio]

There's at least a good chance of temps dropping to or below 32F next week. Here's the probability from earlier today of min temps at least at 32F or below

 

[Phil]

When was the last time the Arctic, USA, and Siberia were all simultaneously colder than average in early November?

[Gradient Keeper]

00z GFS Extracted Output for Moses Lake is nice. Rare early November cold pool becoming established.

http://wxweb.meteostar.com/sample/sample.shtml?run=2017102700&text=KMWH

[Gradient Keeper]

This isn't far off. The ridge starts to retrograde now before day 5. This actually might happen.

[snow_wizard]

The GEM looks good too.

 

It appears all of the models have a mega block in the sweet spot now.  As always the fine details will be the difference between an ok cold snap and something historic.  Historic (for so early in the season) is on the table.

[Gradient Keeper]

It appears all of the models have a mega block in the sweet spot now.  As always the fine details will be the difference between an ok cold snap and something historic.  Historic (for so early in the season) is on the table.

It seems possible ya.

 

00z ECMWF in 4 minutes

[Gradient Keeper]

10/26/17 10:47 PM 00z GFS 500mb Composite Analogs

 

Day 6-10, 8-14 (*1985 popped up 4 times now!)

Correlation score improving a bit more too.

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/500hgt_comp_00gfs610.gif

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/500hgt_comp_00gfs814.gif

[VancouverIslandSouth]

It appears all of the models have a mega block in the sweet spot now.  As always the fine details will be the difference between an ok cold snap and something historic.  Historic (for so early in the season) is on the table.

 

Keeping in mind some of the craziness we saw in the models last March that never panned out. However, it doesn't take as much to give a decent cold snap in November as it does in March and there's generally more moisture to go around/sharper gradients at this time of year.

[stuffradio]

Keeping in mind some of the craziness we saw in the models last March that never panned out. However, it doesn't take as much to give a decent cold snap in November as it does in March and there's generally more moisture to go around/sharper gradients at this time of year.

It was still relatively crazy in March with the snow in early March we got.

[VancouverIslandSouth]

Another sunny and "warm" day here today with thicknesses approaching a ridiculously 570dm, not your typical late October conditions. If this early blast come to fruition that will be quite a dramatic swing in conditions. Wasn't expecting to have to blow out the irrigation system this early.

[wx_statman]

582dm heights up to Kodiak Island on some of those maps. That also happened with the Halloween '03 cold wave. Granted, that pattern was also coupled to a monster 594dm ridge over the SE US.

[VancouverIslandSouth]

It was still relatively crazy in March with the snow in early March we got.

 

Over there it was, but it was nowhere near what the models were showing and on this side of the Strait there wasn't even much snow, just a few 40~45F days with near freezing lows.

[Phil]

My goodness. A +SIOD of this magnitude might be equally as influential as ENSO, in the long run.

 

SSTAs down to -7C right at the equator in the E-IO, relative to the global anomaly. Gonna be tough to sustain convection there this winter.

 

[seattleweatherguy]

My goodness. A +SIOD of this magnitude might be equally as influential as ENSO, in the long run.

 

SSTAs down to -7C right at the equator in the E-IO, relative to the global anomaly. Gonna be tough to sustain convection there this winter.

 

This sounds bad?

[Phil]

This sounds bad?

Not bad. It's just interesting. You typically see the stronger Mascarene High during west based Niños, not second year Niñas.

 

Will make for an interesting battle in the tropics as we move towards the winter solstice.

[TigerWoodsLibido]

 

holy cow!

[snow_wizard]

The WRF shows lowland snow reaching Vancouver BC by next Thursday night.

[Gradient Keeper]

Day 7

Dig!!!!!!!!!!!!

 

http://maps1.pivotalweather.com/maps/models/ecmwf/2017102700/168/500h_anom.na.png

[snow_wizard]

This block looks like it's going to be a beast!  This could be historic.  I would have to think 1935 is the early event on record that would match what is being modeled.

[TT-SEA]

00Z ECMWF very aggressive with the retrogression... surface map shows only 45 at SEA even with partly sunny skies on day 7

[Gradient Keeper]

Day 8

 

http://maps1.pivotalweather.com/maps/models/ecmwf/2017102700/192/500h_anom.na.png

[snow_wizard]

Day 8 on the ECMWF is ridiculous!  Wow!

[TT-SEA]

And then the 00Z ECMWF shows this one week from tonight... into next Friday.

 

[luvssnow_spokane]

Day 8

 

http://maps1.pivotalweather.com/maps/models/ecmwf/2017102700/192/500h_anom.na.png

That makes me as giddy as a school girl at a boy band concert...

[TigerWoodsLibido]

Wow this is going to be close for the WV

[HighlandExperience]

Day 8 on the ECMWF is ridiculous! Wow!

I would have preferred for this to happen towards the end of November. More chance of snow . Exciting though!

[snow_wizard]

The Euro is more than cold enough for snow in the Seattle area.  Really incredible setup.

[TigerWoodsLibido]

That onshore wind can barely keep the valley above freezing!

[snow_wizard]

I would have preferred for this to happen towards the end of November. More chance of snow . Exciting though!

 

I think this early bodes better for winter.

[Gradient Keeper]

6z GFS in 2 hours 22 minutes!

[ShawniganLake]

I think this early bodes better for winter.

Didn’t ‘35 take until February to get anything good going again.

[snow_wizard]

Didn’t ‘35 take until February to get anything good going again.

 

Yes...but it was only the coldest Feb of the 20th century.  Not to mention the amazing late March snow event.

[BLI snowman]

Didn’t ‘35 take until February to get anything good going again.

 

Yeah, weird winter in which December and January both completely sucked while late October, February, and late March all had historic setups.

[ShawniganLake]

Yes...but it was only the coldest Feb of the 20th century. Not to mention the amazing late March snow event.

I knew it was a wicked February, I didn’t realize it was that cold.

[TT-SEA]

Didn’t ‘35 take until February to get anything good going again.

 

There was a few minor chilly periods before February.  But looking at local records here... it was pretty much rainy and in the 40s and 50s for most of December and January that year.