November 2016 Observations and Model Discussion for the Pacific Northwest

[Gradient Keeper]

Aside from 2008, when have the models "flip flopped" back in our favour?

That's a really good and fair point. We usually see far more flopping than flipping, or a combination of flopping, flipping compared to flippity, floppy, flopping, and definitely it's far more often to see flop, flopping, floppity flips, floppity, flopping than anything at all where the cold air slides east. Ultimately I want to see less flopping, flipping, floppity, flopping, than just straight up floppy, flopped, flopping. In 2008 we saw I believe flipping, flippity, flipped, flips, flippered, flippety consistently with maybe 1 or 2 runs featuring a mix of flip, flippity, floppity flops, then reverting back to pure flip, flippity, flipping which ended up just magical for all of us.

[Front Ranger]

Yeah, Euro is definitely a step in the right direction towards the end. More amplified with the ridge building into the Aleutians and way more cold air into North America.

 

Would like to see less energy digging so far out south of AK, but other than that looks pretty good.

[snow_wizard]

1050mb surface high over the Aleutians at day 10 on the ECMWF. Just a small anomaly there.

 

Clear Arctic outbreak signature there.

[crf450ish]

The winds are kinda gusty here in Puyallup. Small but still cool.

[Gradient Keeper]

Yeah, Euro is definitely a step in the right direction towards the end. More amplified with the ridge building into the Aleutians and way more cold air into North America.

 

Would like to see less energy digging so far out south of AK, but other than that looks pretty good.

Yes, initially that's true, but as the offshore ridge backs away retrogressing it merges with the Aleutian block and that will re-configure an amplified block somewhere near 150-160 W. The flow will buckle around and we will have cross polar flow straight from the arctic feeding bitter air continuously into Yukon, Northwest Territories, then down into British Columbia, Alberta, Saskatchewan. I'm not sure if we see the flow sharply bend around to the northeast, or if it's more of a northerly blast with some short-over-water trajectory susceptible to BC Slider systems. It's coming though.

[liquidsnow]

We're talking about 8+ days out, are you being serious right now? When have the models NOT flip flipped in that range? Often times the models will catch on to a pattern change and advertise it too early, only to have it taken away or pushed back for a few days

 

Well sir, I am talking about the countless times where the mirage effects kicks in and the models continue to push any "goods" back to day 10 until the pattern evolves to grade A steaming monkey poop as day 10 becomes day 1 and the mirage eventually disappears and we are left to mourn and conduct an autopsy. That is a definite flop.

 

 

 

That's a really good and fair point. We usually see far more flopping than flipping, or a combination of flopping, flipping compared to flippity, floppy, flopping, and definitely it's far more often to see flop, flopping, floppity flips, floppity, flopping than anything at all where the cold air slides east. Ultimately I want to see less flopping, flipping, floppity, flopping, than just straight up floppy, flopped, flopping. In 2008 we saw I believe flipping, flippity, flipped, flips, flippered, flippety consistently with maybe 1 or 2 runs featuring a mix of flip, flippity, floppity flops, then reverting back to pure flip, flippity, flipping which ended up just magical for all of us.

 

You missed a flippiddy in there. Can't forget that!

[Gradient Keeper]

Well sir, I am talking about the countless times where the mirage effects kicks in and the models continue to push any "goods" back to day 10 until the pattern evolves to grade A steaming monkey poop as day 10 becomes day 1 and the mirage eventually disappears and we are left to mourn and conduct an autopsy. That is a definite flop.

 

 

 

 

You missed a flippiddy in there. Can't forget that!

Yep. Crap. I'll do better next time. I confused myself 2 or 3 times as I typed it, but if you read it slowly and put FLIPPITY, FLIPPING, FLIP, FLIPPED, FLIPS in the context of models giveth us the goods, and FLOPPETY, FLOPPING, FLOPPED, FLOPS models taketh away, then it all makes perfect sense.

[OKwx2k4]

That's a really good and fair point. We usually see far more flopping than flipping, or a combination of flopping, flipping compared to flippity, floppy, flopping, and definitely it's far more often to see flop, flopping, floppity flips, floppity, flopping than anything at all where the cold air slides east. Ultimately I want to see less flopping, flipping, floppity, flopping, than just straight up floppy, flopped, flopping. In 2008 we saw I believe flipping, flippity, flipped, flips, flippered, flippety consistently with maybe 1 or 2 runs featuring a mix of flip, flippity, floppity flops, then reverting back to pure flip, flippity, flipping which ended up just magical for all of us.

That was so worth stopping by to read the last day and a half of the posts over here. Love it!

[Gradient Keeper]

That was so worth stopping by to read the last day and a half of the posts over here. Love it!

I do what I can, when I can. Thanks appreciate the kind words! Lol Happy Thanksgiving to you and yours.

[Phil]

Minor timing issues aside, I like my winter idea, at least for the time being.

 

Finalizing my first set of winter analogs. Will post later tonight.

General theme is a blocky winter overall..A strong NPAC/EPO block develops in November/December as a dominant signal. During January, the NAO block becomes the dominant signal, before the NPAC/EPO becomes dominant again in February/March.

Strongest signal for Arctic air in the PNW is in February, with a decent look in November also.

November:http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/7C4B0E02-66D5-4171-9A8B-6AEB2B3282F1_zpsnjco8k7t.png

December: http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/668A1C0A-08C6-424D-ACD1-5A8D7FDA8E07_zpslz40fnek.png

January:http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/B3945546-46DC-4925-B13E-D09A228DE727_zpsvru6ulno.png

February:http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/8C9A2DC2-B386-4785-8203-CC4783FFA8D4_zpszifsleqr.png

March:http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/4547D03B-B668-4BA5-97C2-A0DA466D658D_zpsbkbj1jli.png

What stands out here is the flip in the NPAC pattern from October to November, and the polar blocking signal peaking in January.

 

I think the only supported conclusion(s) we can reach right now are:

1) Blocking is favored to develop over the NPAC by/during November.

2) Polar blocking (-NAM/-NAO et al) is favored to reach maximum strength during January.

3) While all months show potential for Arctic intrusion for Arctic intrusion into the PNW, the months of November/December and/or February look to hold the strongest signal, while January and March hold a less impressive signal.

4) We'll know by November if winter 2016-17 is following this historical guide, or whether the system goes a different route. If the winter fails, it will probably be due to a strong +EPO/Western-Arctic Vortex pattern.

Still kind of preliminary, but here's my general idea for this winter across North America.

- Covering a range of possibilities, the analogs I'm following most include 1942/43, 1959/60, 1961/62, 1980/81, 1983/84, 1985/86, 1995/96, 2008/09, 2010/11, and 2013/14.

- Overall, from Nov to Mar, I expect a -PNA/-EPO/+NAO look, with a neutral to slightly negative NAM/AO. However, I also anticipate a moderate to significant degree of "pattern variability", on a monthly and/or sub-monthly timescale. Could be frequent intraseasonal pattern changes, given a somewhat unstable background state.

- Overall, I expect normal to below normal temperatures from the Pacific Northwest, down to the Rockies, Northern/Central Plains, Midwest, Great Lakes, and upper New England/Northeast. I anticipate normal to above normal temperatures from the far Southwest, into the Southern Plains, Southeast, up into the coastal Mid Atlantic.

- I anticipate the coldest airmasses (relative to average) to center over the Northern and Central Plains, with much colder than average temperatures from MT, WY, and CO, across the Plains, into MN and IA. I anticipate the warmest airmasses (relative to average) to center over the Gulf and Southeast states.

- I anticipate an early-season Arctic blast into the US during November, following a period of upstream wave breaking as the strengthening PV fights increasing poleward mass fluxes. Exactly how/where it occurs will depend on the nature of the blocking, and the strength of the PV (and the degree of coupling/vertical stacking).

- I anticipate the strongest hemispheric blocking will occur in January, probably reflecting in all domains (-EPO/-AO/-NAO). Though, I also anticipate a systematic tendency to break down the NAO block first, with a vortex trying to develop Southwest of Greenland as the blocking begins to weaken.

Hope to add more clarity over the next several weeks.

[Gradient Keeper]

Minor timing issues aside, I like my winter idea, at least for the time being.

 

 

 

The blocking prophet.

[Gradient Keeper]

6z in 1 hour 43 minutes!!!!

[Bryant]

Minor timing issues aside, I like my winter idea, at least for the time being.

 

 

 

 

I'd say so far you're doing one heck of a job, and I hope that continues for our sake! now check your messenger lol

[snow_wizard]

Minor timing issues aside, I like my winter idea, at least for the time being.

I knew you were dead on before. You shouldn't have gotten such cold feet about it that past several weeks. Other than that good job.

[Phil]

I knew you were dead on before. You shouldn't have gotten such cold feet about it that past several weeks. Other than that good job.

Thank you.

 

FWIW, my concerns were/are confined to November and early December. I never was nervous about the winter failing.

[Phil]

I'd say so far you're doing one heck of a job, and I hope that continues for our sake! now check your messenger lol

Haha, sorry man. Can't seem to get facebook notifications to show up on my new phone.

[Gradient Keeper]

00z ECMWF Ensembles. 500mb anomalies

Amazing agreement with the operational.

 

http://www.tropicaltidbits.com/analysis/models/ecmwf-ens/2016112400/ecmwf-ens_z500a_namer_11.png

 

http://www.tropicaltidbits.com/analysis/models/ecmwf-ens/2016112400/ecmwf-ens_z500a_npac_11.png

[Gradient Keeper]

6z days 5-10 were so colossally awful with the upper level pattern compared to the past 10 runs and ensembles or any of the composite analogs with the 500mb progression being so entirely different you'd almost have to think it was an outlier. I guess we'll find out. It's still somewhat chilly in the lower levels, and definitely so over the Columbia Basin. Bad, crummy, or "unfavorable" model runs are bound to happen when you're 7+ days away from a dramatic pattern change. A lot for models to resolve and handle.

[Gradient Keeper]

Happy Thanksgiving!!!!

11/24/16 3:23 AM [ Model Countdown ]

Next up....

*12z GFS in 4 hours 5 minutes

12z CMC/GEM in 5 hours 5 minutes

12z ECMWF in 6 hours 22 minutes

[OKwx2k4]

I do what I can, when I can. Thanks appreciate the kind words! Lol Happy Thanksgiving to you and yours.

Thank you! Happy Thanksgiving to you as well!

[SilverFallsAndrew]

This model is giving my location nearly 6" of rain...Yikes

 

http://www.cascadeaccess.com/~mnelsen/RPM_RAIN_NWOREGON.jpg

[TT-SEA]

This model is giving my location nearly 6" of rain...Yikes

 

http://www.cascadeaccess.com/~mnelsen/RPM_RAIN_NWOREGON.jpg

 

 

 

Something to be thankful for today... we really need the rain.    We are becoming SoCal.   It never rain here any more.   

[Heavy Snow]

 

Happy Thanksgiving!!!!

11/24/16 3:23 AM [ Model Countdown ]

Next up....

*12z GFS in 4 hours 5 minutes

12z CMC/GEM in 5 hours 5 minutes

12z ECMWF in 6 hours 22 minutes

 

 

Happy Thanksgiving to everybody! We all have a lot to be thankful for this Thanksgiving. I'm thankful for all the models. I apologize for leaving anybody out but the CFS, JMA, UKMET, NAM, GEM, GFS and EURO for always providing us with great model runs and providing excitement in our lives!

[IbrChris]

Or, maybe the warm Arctic was/is a result of the unprecedentedly strong -NAM and weak stratospheric PV regime that's been ongoing since September? A weak equator/pole thermal gradient is something you'd generally expect from a -NAM/weak PV regime, not necessarily a cause. Where the PV has been located (Eurasia), record breaking cold has been observed.

 

Back in early September, the polar stratosphere became heavily perturbed/warm relative to average, and the troposphere followed a few weeks thereafter. No?

I made a general inference, not a prediction. The inference isn't just based on what we've been seeing the last few months, we have seen high latitude blocking and a weak polar jet several winters out of the last 5 or 6.

 

Good article by Dr Judah Cohen discussing a potential link between "Arctic amplification" (extreme Arctic warming) and increased mid-latitude pattern volatility and frequency of "extreme" events.

 

"The second proposed dynamical pathway linking Arctic amplification to increased weather extremes is through its effects on the behaviour of the polar jet stream. The difference in temperature between the Arctic and mid-latitudes is a fundamental driver of the polar jet stream; therefore, a reduced poleward temperature difference could result in a weaker zonal jet with larger meanders. A weaker and more meandering flow may cause weather systems to travel eastward more slowly and thus, all other things being equal, Arctic amplification could lead to more persistent weather patterns. Furthermore, Arctic amplification causes the thickness of atmospheric layers to increase more to the north, such that the peaks of atmospheric ridges may elongate northward and, thus, increase the north–south amplitude of the flow. Weather extremes frequently occur when atmospheric circulation patterns are persistent, which tends to occur with a strong meridional wind component." (p 5)

 

http://web.mit.edu/jlcohen/www/papers/Cohenetal_NGeo14.pdf

 

The jury is still out on what effect if any Arctic amplification is having on mid-latitude wintertime patterns, though it is certainly not the sole driver in any case...Overland (2015) provides an analysis of recent studies that suggest changes in the Arctic can impact some areas more than others...for example Eurasia versus eastern NA/western Europe.

 

http://journals.ametsoc.org/doi/full/10.1175/JCLI-D-14-00822.1

 

 

It is very possible both mechanics (-NAM/weak stratospheric PV and effects of Arctic amplification) are playing a role in mid-latitude patterns this fall/early winter.

[FroYoBro]

Today looks insanely wet. The heavy band that should stay with us for the day is already arriving in the northern valley right now. 

[Jesse]

What a mild week so far.

[Deweydog]

What a mild week so far.

 

Aftershocks leading up to the warnings shots.  

[luvssnow_spokane]

[Jesse]

Aftershocks leading up to the warnings shots.  

 

Is that how we're rationalizing things now?

[TT-SEA]

I remember last week looking at this 4-day holiday weekend and it was shown to be dry with offshore flow.  

 

That sure fell apart.   The ECMWF was never really sold on the idea so that was probably a good clue it was not going to happen.

[Jesse]

I for one am thankful for the very heavy rain moving in this morning.

[Timmy]

I for one am thankful for the very heavy rain moving in this morning.

It's pretty cool outside too!

[TT-SEA]

Good day at Snoqualmie Pass finally... hope the east wind keeps going with all this moisture.

 

[SilverFallsAndrew]

2" already at Astoria. Their daily record is 2.94" in 1990, tomorrows record is from 1998, and Saturday's is from 1955....Hmmm wet around Thanksgiving =? lol

[Deweydog]

How 'bout that 12z???

[Heavy Snow]

How 'bout that 12z???

It looks great. The updated run of the 12z GFS shows a Mammoth North Pacific Block at Day 15. It might be a little too far west but the exact placement will surely change. The most important thing is the Block.

 

http://www.tropicaltidbits.com/analysis/models/gfs/2016112412/gfs_z500a_npac_51.png

[Sometimesdylan]

How 'bout that 12z???

 

Pretty nice looking for up here. Almost 6 inches of liquid precip through hour 180 and 925mb temps don't go above 0! I'll take it!

[SilverFallsAndrew]

Still looking good for 1000-1500' snow levels mid next week... First week of December looking fairly damp. 

[MossMan]

Insanely wet, my driveway is underwater. 43F. Sure hope we get handsomely rewarded for two straight months of rain almost every single day. Today reminds me of 1990 for some reason.

[snow_wizard]

The temperature has been falling here since sunrise. Down to 45 now.

 

On another note there was another huge improvement on the ECMWF ensemble on the last run.