October 2016 Observations and Model Discussion for the Pacific Northwest

[Phil]

Note there hasn't been a single -PNA day in October so far..

 

After a +PNA October, we definitely don't want to see November follow with another +PNA. Very ugly stats on -ENSO years w/ back to back +PNAs in Oct/Nov, with a few exceptions.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/pna.sprd2.gif

[snow_wizard]

Note there hasn't been a single -PNA day in October so far.

 

After a +PNA October, we definitely don't want to see November follow with another +PNA. Very ugly stats on -ENSO years w/ back to back +PNAs in Oct/Nov.

 

 

We did have that major block that would have caused a major Arctic blast (if it had been winter) earlier in the month though.  You seem to freaking out a bit.

[TT-SEA]

I-90 westbound into Issaquah this morning...

 

[snow_wizard]

Dropped down to a chilly 36F for a low this morning. Cold and damp out there.

 

Pleasant surprise how chilly it got last night.

[Phil]

We did have that major block that would have caused a major Arctic blast (if it had been winter) earlier in the month though. You seem to freaking out a bit.

I'm still optimistic for you this winter. Always have been.

 

I'll be less optimistic if November runs another +PNA, though.

[wx_statman]

I wonder how they did in Jan 1913.  That month was pure madness for Clearbrook.

 

That was a great month for snowfall.

 

89.1" at Agassiz

70.6" at Chilliwack

64.8" at New Westminster

64.6" at Clearbrook

57.3" at Vancouver (Port Meteorological Office)

51.0" at Shawnigan Lake

47.8" at Coquitlam

[ShawniganLake]

That was a great month for snowfall.

 

89.1" at Agassiz

70.6" at Chilliwack

64.8" at New Westminster

64.6" at Clearbrook

57.3" at Vancouver (Port Meteorological Office)

51.0" at Shawnigan Lake

47.8" at Coquitlam

I appreciate Shawnigan Lake being included in the mix. Not super common to see Vancouver that much snowier than over here.

[wx_statman]

I appreciate Shawnigan Lake being included in the mix. Not super common to see Vancouver that much snowier than over here.

 

There were some funky gradients with the snowfall totals that month. Nanaimo had 32.0" with only 25.6" at the Departure Bay station. Downtown Bellingham had even less at 21.5", and by the time you got to Seattle the totals were only around 12". 

[Front Ranger]

Note there hasn't been a single -PNA day in October so far..

 

After a +PNA October, we definitely don't want to see November follow with another +PNA. Very ugly stats on -ENSO years w/ back to back +PNAs in Oct/Nov, with a few exceptions.

 

What -ENSO years have seen that? I imagine it's a fairly short list.

[MossMan]

It will snow...a lot...this winter. That is my highly scientific input for the forum, no need to worry about Hadley cells, PNA's NAO's, blobs...none of that mumbo jumbo gobley goo. Fat squirrels, my dogs thick tail, and a mouse trying to make a home in the back of my truck are sure signs that this will be a doozy!!

[Phil]

What -ENSO years have seen that? I imagine it's a fairly short list.

Eliminating stronger Niñas, the most recent years are 1959/60, 1980/81, 1983/84, and 2008/09, though 1983/84 and 2008/09 aren't very similar pattern wise.

 

Stronger Niñas that accomplished this include 1974/75, 1988/89, 1998/99, 1999/00, 2000/01, and 2007/08. Mostly crappy winters except for 1988/89.

[Phil]

12z EPS is still bullish on the +PNA/+WPO through d15, FWIW.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/DB7091E0-3881-40BB-AE1F-8482AAC44F4B_zps3m3iwsju.png

[ShawniganLake]

12z EPS is still bullish on the +PNA/+WPO through d15, FWIW.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/DB7091E0-3881-40BB-AE1F-8482AAC44F4B_zps3m3iwsju.png

Warm and wet. Feels like it might flip the second half of November.

[Phil]

Warm and wet. Feels like it might flip the second half of November.

That's been my thinking too..about a week before thanksgiving?

[TT-SEA]

That's been my thinking too..about a week before thanksgiving?

 

 

White Thanksgiving for me!  

[ShawniganLake]

That's been my thinking too..about a week before thanksgiving?

My original feeling was that December and February would be our 2 best months. Could be another bookend winter in the works.

[Phil]

My original feeling was that December and February would be our 2 best months. Could be another bookend winter in the works.

Many of the analogs are hinting at February, yeah. Personally I think the strongest blocking will set up during January, but exactly where is another story. Hard for me to tell.

[ShawniganLake]

Many of the analogs are hinting at February, yeah. Personally I think the strongest blocking will set up during January, but exactly where is another story. Hard for me to tell.

Seemed like the analogues were hinting at something in the mid November to early December frame. And then again in February. Maybe it ends up just good throughout. A little something every month would be nice too.

[snow_wizard]

Seemed like the analogues were hinting at something in the mid November to early December frame. And then again in February. Maybe it ends up just good throughout. A little something every month would be nice too.

 

I really hope we skip November.  I suppose we could get away with a borderline snow.  The thing we want to avoid is extreme blocking with a major cold wave in November.

[snow_wizard]

My original feeling was that December and February would be our 2 best months. Could be another bookend winter in the works.

 

January has to deliver one of these days.  I think it's close, but who knows if this will be the winter or not.  FWIW the CFS has really been liking Feb lately with some excellent runs for Jan as well.

[Phil]

I really hope we skip November. I suppose we could get away with a borderline snow. The thing we want to avoid is extreme blocking with a major cold wave in November.

I still don't understand your line of thinking here. There aren't any analog years that featured a +PNA in both October and November, followed by an Arctic blast in January. None. Zero.

 

Why would you root for something that'd statistically eliminate your chance for a midwinter blast?

 

Is this just a hunch? Not saying I have the answers, but the past is often prologue in cases like this, IMO.

[luvssnow_spokane]

I still don't understand your line of thinking here. There aren't any analog years that featured a +PNA in both October and November, followed by an Arctic blast in January. None. Zero.

 

Why would you root for something that'd statistically eliminate your chance for a midwinter blast?

 

Is this just a hunch? Not saying I have the answers, but the past is often prologue in cases like this, IMO.

I do not think his "rooting" will make a big difference what the outcome is... Just saying      Let him root ... we get what we get and it may be s**t or a big hit... OOOOoooo poetic.

[Tundra]

12z EPS is still bullish on the +PNA/+WPO through d15, FWIW.

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/DB7091E0-3881-40BB-AE1F-8482AAC44F4B_zps3m3iwsju.png

 

The newest editions of the 12z GEFS and GEPS look very similar. Strong agreement between all 3.

 

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2016102212/gfs-ens_z500a_namer_61.png

http://www.tropicaltidbits.com/analysis/models/gem-ens/2016102212/gem-ens_z500a_namer_61.png

[Phil]

I do not think his "rooting" will make a big difference what the outcome is... Just saying Let him root ... we get what we get and it may be s**t or a big hit... OOOOoooo poetic.

Lol, wasn't trying to suggest he's god in disguise. Just trying to understand his line of thinking here, that's all.

[Tundra]

I looked at the latest D+11 SUPER GFS ENSEMBLES and noticed the strongest correlations to the upcoming weather pattern is the Winter of 1983-84. This makes sense because 1982-1983 was a very strong El Nino that went into a weak La Nina. As we all know we are all going from a very strong El Nino to possibly the most likely scenario of a weak La Nina as well.

 

http://i.imgur.com/c1ucMnc.gif

 

The Winter of 1983-1984 featured an Arctic blast the last half of December in the PNW. BLI had 8 straight sub freezing highs, PDX had 6, SEA had 5 and YVR had 8 days of highs 33 or lower. The Winter of 83-84 might be our best analog.

[Phil]

I'd like the 1983/84 analog a lot more if it didn't feature a supermassive black hole at the North Pole. Otherwise, it's a pretty good one IMO.

 

FWIW, I think there's a good chance we see the lowest October AO in recorded history this year. Definitely notable/important in regards to forward progression/extrapolative analoging.

[TT-SEA]

Nice fall color from the Space Needle cam this afternoon...

 

[Phil]

The 00z GFS is depicting the craziest +WPO/+PNA/-AO pattern I've ever seen. Holy smokes.

[seattleweatherguy]

The 00z GFS is depicting the craziest +WPO/+PNA/-AO pattern I've ever seen. Holy smokes.

For dummies like me what does that mean in laymans terms?

[snow_wizard]

It is interesting to note the "old formula" PNA does show we have had some negative PNA episodes this month.  I have never understood the finer points of the new formula, but sometimes it doesn't show negative PNA when we have a GOA ridge / Western trough.  I would also like to make the point it might be fine to have negative PNA in November, but I want to avoid significant cold weather during the month.  Hope that clears everything up.

 

ftp://ftp.cdc.noaa.gov/Public/gbates/reforecast2/teleconn/pna.png

[snow_wizard]

A lot of really nice analogs to tonight's 0z GFS and the correlation scores are much improved from recent days.  Many of the analogs are from winters that had major blocking episodes.

[Phil]

It is interesting to note the "old formula" PNA does show we have had some negative PNA episodes this month. I have never understood the finer points of the new formula, but sometimes it doesn't show negative PNA when we have a GOA ridge / Western trough. I would also like to make the point it might be fine to have negative PNA in November, but I want to avoid significant cold weather during the month. Hope that clears everything up.

 

ftp://ftp.cdc.noaa.gov/Public/gbates/reforecast2/teleconn/pna.png

Improved domainal consistency and overlap in the new version.

 

Semantics aside, October will clearly finish as a coherent +PNA month. Not much GOA blocking, but plenty of polar blocking, which is a good thing in the long run.

 

However, noting this fact, a warm/+PNA November is something that we'd want to avoid at all costs after a +PNA October. Analogs get ugly fast when you start stringing +PNA months together like that during the autumn, regardless of ENSO/QBO, as it's often reflective of a background boundary state of some sort.

[TT-SEA]

Improved domainal consistency and overlap in the new version.

 

Semantics aside, October will clearly finish as a coherent +PNA month. Not much GOA blocking, but plenty of polar blocking, which is a good thing in the long run.

 

However, noting this fact, a warm/+PNA November is something that we'd want to avoid at all costs after a +PNA October. Analogs get ugly fast when you start stringing +PNA months together like that during the autumn, regardless of ENSO/QBO, as it's often reflective of a background boundary state of some sort.

 

 

Jim says we want a warm and wet November... you say we want -PNA and some blocking.  

 

So no matter what happens ir will be a great thing for us!  

[TT-SEA]

00Z GFS ensemble mean is above normal the entire run

 

http://old.wetterzentrale.de/pics/MT8_Seattle_USA_ens.png

[stuffradio]

2008 was warm until ~mid-December. I just want snow.

[Brennan]

October 1949 was cold and wet, followed by a November torch... I think that is the main line of thinking behind cold october/warm november combos. 

[TT-SEA]

There have only been 4 days below normal in October at SEA so far and yet the monthly departure is only +1.   

 

Consistently above normal but by a small margin.    

[Bryant]

00Z GFS ensemble mean is above normal the entire run

 

http://old.wetterzentrale.de/pics/MT8_Seattle_USA_ens.png

Do you expect anything different right now? Goes without saying

[TT-SEA]

Do you expect anything different right now? Goes without saying

 

Sorry sir.   I did not mean to post anything about the upcoming weather for the next 2 weeks

 

 

Am I not kissing your a** enough?

[BLI snowman]

Nice to see us keep our streak alive. With the late evening showers we've now had measurable rain on 20/22 days this month.