November 2016 Observations and Model Discussion for the Pacific Northwest

[IbrChris]

SPC coming out with a reactionary "marginal risk" area along the immediate central Oregon coast.

[IbrChris]

12Z ECMWF sure looks exciting in the 8-10 day period!   

 

That's a healthy low-amplitude Rex Block in the western US...the only cold coming from that pattern is from fogversions. Though it looks like the axis is well inland so more likely we'd just be getting mild and wet here.

[Dave]

I don't think I've ever seen this much lightning off the Oregon coast at any time of the year.

 

http://www.cascadeaccess.com/~mnelsen/lightning2.jpg

[Jesse]

That's a healthy low-amplitude Rex Block in the western US...the only cold coming from that pattern is from fogversions. Though it looks like the axis is well inland so more likely we'd just be getting mild and wet here.

 

It looks to me like the northern stream energy is about to swing right in. I don't think whatever quasi-Rex block is there would put up too much of a fight. Just extrapolating from that frame.

[Dave]

It's been really windy for hours down here in Eugene, not to mention warm and not a drop of rain yet.  I'm a bit surprised a wind advisory wasn't issued.  Take a look at all the gusts in Eugene so far today.

 

http://www.wrh.noaa.gov/mesowest/getobext.php?wfo=pqr&sid=KEUG&num=72&raw=0

[BLI snowman]

Unfortunately, Battle Ground is missing some data. 

 

It does look like they had top 5 cold months in April 2008, April 2011, March 2012, May 2011, October 2013, Dec 2013, and Dec 2009. 7 months, just like OLM.

 

Battle Ground's data is pretty messy over the years, I wouldn't put much stock in their temp numbers.

[ShawniganLake]

That's a healthy low-amplitude Rex Block in the western US...the only cold coming from that pattern is from fogversions. Though it looks like the axis is well inland so more likely we'd just be getting mild and wet here.

Am I correct in thinking that that cutoff low down south is kind of what is throwing off the much anticipated pattern change. We want to see that low ejecting to the east?

[Jesse]

Battle Ground's data is pretty messy over the years, I wouldn't put much stock in their temp numbers.

 

That would only be an issue if they ran warm.

[Front Ranger]

Battle Ground's data is pretty messy over the years, I wouldn't put much stock in their temp numbers.

 

It wasn't my first choice. You'll note in my post I said they are missing some data. Chris just asked about that station since it's rural like OLM and closer to PDX.

 

But it's unlikely the results would be much different even with full data, in this case.

[Timmy Supercell]

Forgot to post that the first 15 days of November 2016 in Klamath Falls had an average high of 61.5, with the normal being 49.5 in that period. Running +12.0 degrees. The 2nd half of this month does not look like it will run cooler than normal, if it does - not by much. Good chance this is going to be another anomaly, just like October was with cooler temps. 2 months of exact mirror opposites in a row. This is a really interesting year overall.

[Timmy Supercell]

I don't think I've ever seen this much lightning off the Oregon coast at any time of the year.

 

http://www.cascadeaccess.com/~mnelsen/lightning2.jpg

 

There actually have been quite a few times more lightning happened offshore but I cannot recall dates offhand. 

 

Nonetheless pretty impressive front and streaks of CG's.

[Phil]

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.

I think the cause/effect jury is still out. There seems to be plenty of literature on both sides of the isle regarding the nature/reason(s) of/for Arctic amplification, and if/how it may either impact and/or arise from changes in circulation.

 

http://www.tellusa.net/index.php/tellusa/article/view/25482

 

http://onlinelibrary.wiley.com/doi/10.1002/wcc.337/full

 

http://onlinelibrary.wiley.com/doi/10.1029/2010GL044136/full

 

https://www.atm.helsinki.fi/peex/images/Workshop_proceedings_NERSC-Tech-report_290216-MASTER_ESAU.pdf#page=16

 

http://onlinelibrary.wiley.com/doi/10.1002/2015GL065923/full

 

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0320.1

[Heavy Snow]

I think 'we' are closing in on a solution, the Euro still has a few more runs to go to lock on to what we want it to lock on to.  There is a lot of arctic air ready to slide down, question is, will it slide into the PNW or Wisconsin and Michigan...?

 

Based on where the Block is setting up, I don't see it sliding into the Midwest without at least giving us a modified Arctic Blast. The updated run of the 12z EPS is in great agreement with the Operational 10 days out. Based on the EPS it looks like more retrogression after Day 10 and we should really see the Block amplify even more.

 

http://maps1.pivotalweather.com/maps/models/eps/2016112412/240/500h_anom.na.png

[Jesse]

Gust to 41mph at PDX.

 

Stormy turkey day. We're about to commute right through it.

[Timmy Supercell]

Keeping it real mid June through Oct was not a torch. A bit above normal in some places below normal more inland. The mountains are getting tons of snow now. We just came off of a MAJOR torch. It takes time to come down from that. I wanted the warm November anyway.

 

Here east of the southern cascades the entire summer 2016 was just a BLIP above normal. Not even by a degree. July by itself was even cooler than average.

[TT-SEA]

Plowing now at Snoqualmie Pass... my son is watching this non-stop.   

 

 

Not even raining here... and dead calm.   I doubt we have even seen .10 for the day.     

[MossMan]

My gut that will soon be filled with Thanksgiving goodness is telling me that the models will start locking onto something really good in a few days and that we will be seeing the goods around the 13th!

[Farmboy]

My gut that will soon be filled with Thanksgiving goodness is telling me that the models will start locking onto something really good in a few days and that we will be seeing the goods around the 13th!

I'm rooting for that 2008 analog!!

[Heavy Snow]

My gut that will soon be filled with Thanksgiving goodness is telling me that the models will start locking onto something really good in a few days and that we will be seeing the goods around the 13th!

 

Your gut is going to be right!

[Front Ranger]

Off to do Thanksgiving stuff...I leave you with the 12z Euro ensemble mean at day 10.

 

 

[Abbotsford_wx]

Plowing now at Snoqualmie Pass... my son is watching this non-stop.   

 

 

 

Not even raining here... and dead calm.   I doubt we have even seen .10 for the day.     

 

I can beat that... I've seen less than a hundredth in the last 24 hours.

[Timmy Supercell]

I can beat that... I've seen less than a hundredth in the last 24 hours.

 

I can beat all of that. Exactly 0.00" last 24 hours and counting...

[Cold front]

I got around 1.24 the last 4 hours. Most gloomy day this Fall.

[MossMan]

I take it the drunk uncle sobered up a bit today?

[ShawniganLake]

I take it the drunk uncle sobered up a bit today?

He finally had too many and went over the edge. Fell flat on his face. Ensemble looks similar.

[Heavy Snow]

Long-range thoughts from Brett Anderson regarding potential blocking and where it might set up.

 

"Early December could be rather interesting from a meteorological standpoint with the potential for blocking high pressure near Greenland, which forces cold air down through the Prairies and into the central U.S. However, if you want to get the cold and snow into the east, we would need a blocking high more over western Canada which is not being shown. Instead, modeling is showing the high farther west in the northern Pacific. As has been the case recently, the far north has been cooperating for snow lovers in the east with rounds of blocking highs, while the Pacific has not with surges of mild, Pacific air with the strong jet. We still think the best potential for full cooperation between the far north and Pacific will come sometime in January."

 

http://www.accuweather.com/en/weather-blogs/anderson/heavy-snow-for-the-western-bc-ski-resorts/61812959

[Gradient Keeper]

00z in 3 hours 12 minutes!!!!

 

I hope you are all having a great Thanksgiving

[Gradient Keeper]

Long-range thoughts from Brett Anderson regarding potential blocking and where it might set up.

 

"Early December could be rather interesting from a meteorological standpoint with the potential for blocking high pressure near Greenland, which forces cold air down through the Prairies and into the central U.S. However, if you want to get the cold and snow into the east, we would need a blocking high more over western Canada which is not being shown. Instead, modeling is showing the high farther west in the northern Pacific. As has been the case recently, the far north has been cooperating for snow lovers in the east with rounds of blocking highs, while the Pacific has not with surges of mild, Pacific air with the strong jet. We still think the best potential for full cooperation between the far north and Pacific will come sometime in January."

 

http://www.accuweather.com/en/weather-blogs/anderson/heavy-snow-for-the-western-bc-ski-resorts/61812959

I'm surprised how great January 1969 was without what appears to be no positive anomaly/ridging over the southeast US.

 

00z GFS in 3 hours 7 minutes

[snow_wizard]

It looks to me like the northern stream energy is about to swing right in. I don't think whatever quasi-Rex block is there would put up too much of a fight. Just extrapolating from that frame.

The ECMWF ensemble mean and control model both get pretty cold in the 11 to 15 day period. We have another solid cold shot coming before that also with 850s dropping to -5 or -6.

[snow_wizard]

Off to do Thanksgiving stuff...I leave you with the 12z Euro ensemble mean at day 10.

 

get_orig_img.gif

Bloody impressive anomalies for day 10. Perfect placement also.

[Gradient Keeper]

00z GFS in 1 hour!!!!

[Heavy Snow]

I'm surprised how great January 1969 was without what appears to be no positive anomaly/ridging over the southeast US.

 

00z GFS in 3 hours 7 minutes

 

Yeah me too.

[Heavy Snow]

00z GFS in 1 hour!!!!

 

I'm ready!!!!!

[Gradient Keeper]

00z GFS
Days 3-7 don't expect much if any changes. Would be nice to see less amplification of our offshore ridge during this period. Days 7-10 hoping to see improvements near 160 W westward to east Asia. Need to see the ridge near the Aleutians amplifying.

Feel free to play along(You may need to refresh pages)
Northwest view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nwus&pkg=mslp_pcpn_frzn&runtime=2015092718&fh=6&xpos=0&ypos=197
North America view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=namer&pkg=z500_mslp&runtime=2016111618&fh=6&xpos=0&ypos=471
North Pacific view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=npac&pkg=z500_mslp&runtime=2016111618&fh=6

[crf450ish]

What snow level is 540 thickness?

[Gradient Keeper]

What snow level is 540 thickness?

Rough Guide to Snow level in PNW

By Chris Callais on Monday, February 10, 2014 at 12:18pm

Rough guide to determining 50% snow criteria for western Oregon/Washington. 50% snow criteria meaning given at least one of these criteria are met snow would be expected in 50% of cases assuming moderate precip.

 

Elevation....500 mb thickness (dam)....850 mb temp ©....850 mb thickness (dam)

Sea level....526.......-8......129

500'...........528.......-7

1000'.........530.......-6

2000'.........534.......-4

3000'.........538.......-2

4000'.........542.......0

5000'.........546.......+2

6000'.........550.......+4

7000'.........554.......+6

8000'.........558.......+8

9000'.........562.......+10

10000'.......566.......+12

11000'.......570.......+14

12000'.......574.......+16

 

Basically for every 1000' in elevation change a change of 4 dam in thickness or 2c in 850 mb temp

[liquidsnow]

00z GFS

Days 3-7 don't expect much if any changes. Would be nice to see less amplification of our offshore ridge during this period. Days 7-10 hoping to see improvements near 160 W westward to east Asia. Need to see the ridge near the Aleutians amplifying.

 

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

Northwest view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nwus&pkg=mslp_pcpn_frzn&runtime=2015092718&fh=6&xpos=0&ypos=197

North America view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=namer&pkg=z500_mslp&runtime=2016111618&fh=6&xpos=0&ypos=471

North Pacific view - http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=npac&pkg=z500_mslp&runtime=2016111618&fh=6

 

This isn't looking so good so far...EWWWWWWWWW

 

http://www.tropicaltidbits.com/analysis/models/gfs/2016112500/gfs_z500_mslp_npac_26.png

[Gradient Keeper]

HR 138 Aleutian low is overpowering our offshore ridge shoving it around like a little baby more so than previous runs.

 

http://www.tropicaltidbits.com/analysis/models/gfs/2016112500/gfs_z500_mslp_npac_24.png

[SilverFallsAndrew]

Why does our weather always suck?

[SilverFallsAndrew]

3.50" of rain at Astoria today so far. 

 

1.50" at PDX.