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November 2016 Observations and Model Discussion for the Pacific Northwest


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18z GFS 500mb Composite Analog Day 8-14

Huge improvement. Massive pattern shift revealed. Much stronger positive anomaly with good amplification over AK. Negative anomaly/colder air all throughout Nunavut, Northwest Territories. Arctic trough digging southwestward down through BC/AB into WA/OR/ID. Some very cold and snow years showing up! I'd like to see the correlation coefficient rate higher 95% or so, and the trough a tad further west, but this is looking promising. Hmmm.

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/500hgt_comp_18gfs814.gif

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18z GFS 500mb Composite Analog Day 8-14

Huge improvement. Massive pattern shift revealed. Much stronger positive anomaly with good amplification over AK. Negative anomaly/colder air all throughout Nunavut, Northwest Territories. Arctic trough digging southwestward down through BC/AB into WA/OR/ID. Some very cold and snow years showing up! I'd like to see the correlation coefficient rate higher 95% or so, and the trough a tad further west, but this is looking promising. Hmmm.

 

 

 

Forcing pushing into the east IO/Maritime region during that time frame, flips the NAO and supports a healthy ridge over the NPAC. Starting to line up nicely 

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I think we should let drunk uncle run around a bit longer today. I caught him the past couple days and we know how the 00z turned out after that. I want to see where he goes now.

Tell the drunk uncle 18z his presence is requested over on the Political Banter thread.

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The Pacific Northwest: Where storms go to die.

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18z GFS 500mb Composite Analog Day 8-14

Huge improvement. Massive pattern shift revealed. Much stronger positive anomaly with good amplification over AK. Negative anomaly/colder air all throughout Nunavut, Northwest Territories. Arctic trough digging southwestward down through BC/AB into WA/OR/ID. Some very cold and snow years showing up! I'd like to see the correlation coefficient rate higher 95% or so, and the trough a tad further west, but this is looking promising. Hmmm.

 

I'm just waiting for the naysayers to chime in:

 

"Bu- but there's not a 588 ridge over Anchorage. Any hopes of 490s thicknesses over southern BC are dashed!"

 

"It's anticyclonic wavebreaking...get ready for a beefy Aleutian low and a month of mild SW flow with a raging +PNA/+EPO."

 

Well that's a bit hyperbolic...but you get the picture.

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The Pacific Northwest: Where storms go to die.

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18z GFS 500mb Composite Analog Day 8-14

Huge improvement. Massive pattern shift revealed. Much stronger positive anomaly with good amplification over AK. Negative anomaly/colder air all throughout Nunavut, Northwest Territories. Arctic trough digging southwestward down through BC/AB into WA/OR/ID. Some very cold and snow years showing up! I'd like to see the correlation coefficient rate higher 95% or so, and the trough a tad further west, but this is looking promising. Hmmm.

 

http://www.cpc.ncep.noaa.gov/products/predictions/short_range/tools/gifs/500hgt_comp_18gfs814.gif

That's a promising sign. I love that 2008 analog showing up.

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f3e7e3bf2f29b1e9cdb92d7e39e709f1.jpg

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It's been brought up a few times on these forums on whether a warmer Arctic in winter would lead to a generally weaker, more meridional jet more prone to blocking patterns. Personally I see some validity to that view. I also agree with some of the current analysis and thinking re: a record warm Arctic/record low Nov Arctic sea ice has correlation to a weak polar jet, high latitude blocking and generally more extreme seasonal variability in the mid-latitudes. This seems likely to carry on into December and I feel that if the longwave pattern turns favorable across North America there's a very real risk of a historic arctic blast into the lower 48 this winter. Potentially something along the lines of 1983 or 1990 (not necessarily in December), or perhaps Jan 1979. Then again the stagnant pattern could always vary little from the present configuration promoting warmth over NA and cold across Eurasia for much of the winter...time will tell. I've never felt comfortable simply saying that a warm arctic means mild mid-latitudes, which seems to be a common refrain around here as of late. It doesn't need to be -40 in Yellowknife to have a healthy snowcover either. If the weak/meandering jet theory is true, along with a greater likelihood of blocking it's only a numbers game until a favorable blocking pattern develops and we score a major blast (either regionally or the entire CONUS).

I should mention cold airmasses easily form in situ over snow-covered expanses given the long nights and predominantly clear conditions across north-central North America in winter. I've seen the same effect in the Great Basin in winter when a strong high develops and inversions progressively deepen with time due to a negative radiative imbalance over snow-covered ground.

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The Pacific Northwest: Where storms go to die.

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Looking pretty likely we will at least see some chilly weather and low snow levels as we enter December. It's well worth noting the 12z ECMWF ensemble is way colder than previous runs for the NW. It's also interesting to look at the mean of the past 28 runs of the CFS. 28 runs lends some credence to this.

post-222-0-30869300-1479954486_thumb.png

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Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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It's been brought up a few times on these forums on whether a warmer Arctic in winter would lead to a generally weaker, more meridional jet more prone to blocking patterns. Personally I see some validity to that view. I also agree with some of the current analysis and thinking re: a record warm Arctic/record low Nov Arctic sea ice has correlation to a weak polar jet, high latitude blocking and generally more extreme seasonal variability in the mid-latitudes. This seems likely to carry on into December and I feel that if the longwave pattern turns favorable across North America there's a very real risk of a historic arctic blast into the lower 48 this winter. Potentially something along the lines of 1983 or 1990 (not necessarily in December), or perhaps Jan 1979. Then again the stagnant pattern could always vary little from the present configuration promoting warmth over NA and cold across Eurasia for much of the winter...time will tell. I've never felt comfortable simply saying that a warm arctic means mild mid-latitudes, which seems to be a common refrain around here as of late. It doesn't need to be -40 in Yellowknife to have a healthy snowcover either. If the weak/meandering jet theory is true, along with a greater likelihood of blocking it's only a numbers game until a favorable blocking pattern develops and we score a major blast (either regionally or the entire CONUS).

 

I should mention cold airmasses easily form in situ over snow-covered expanses given the long nights and predominantly clear conditions across north-central North America in winter. I've seen the same effect in the Great Basin in winter when a strong high develops and inversions progressively deepen with time due to a negative radiative imbalance over snow-covered ground.

\

Yeah see January 2013 in the Great Basin. 

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Snowfall                                  Precip

2022-23: 95.0"                      2022-23: 17.39"

2021-22: 52.6"                    2021-22: 91.46" 

2020-21: 12.0"                    2020-21: 71.59"

2019-20: 23.5"                   2019-20: 58.54"

2018-19: 63.5"                   2018-19: 66.33"

2017-18: 30.3"                   2017-18: 59.83"

2016-17: 49.2"                   2016-17: 97.58"

2015-16: 11.75"                 2015-16: 68.67"

2014-15: 3.5"
2013-14: 11.75"                  2013-14: 62.30
2012-13: 16.75"                 2012-13: 78.45  

2011-12: 98.5"                   2011-12: 92.67"

It's always sunny at Winters Hill! 
Fighting the good fight against weather evil.

 

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It's been brought up a few times on these forums on whether a warmer Arctic in winter would lead to a generally weaker, more meridional jet more prone to blocking patterns. Personally I see some validity to that view. I also agree with some of the current analysis and thinking re: a record warm Arctic/record low Nov Arctic sea ice has correlation to a weak polar jet, high latitude blocking and generally more extreme seasonal variability in the mid-latitudes. This seems likely to carry on into December and I feel that if the longwave pattern turns favorable across North America there's a very real risk of a historic arctic blast into the lower 48 this winter. Potentially something along the lines of 1983 or 1990 (not necessarily in December), or perhaps Jan 1979. Then again the stagnant pattern could always vary little from the present configuration promoting warmth over NA and cold across Eurasia for much of the winter...time will tell. I've never felt comfortable simply saying that a warm arctic means mild mid-latitudes, which seems to be a common refrain around here as of late. It doesn't need to be -40 in Yellowknife to have a healthy snowcover either. If the weak/meandering jet theory is true, along with a greater likelihood of blocking it's only a numbers game until a favorable blocking pattern develops and we score a major blast (either regionally or the entire CONUS).

 

I should mention cold airmasses easily form in situ over snow-covered expanses given the long nights and predominantly clear conditions across north-central North America in winter. I've seen the same effect in the Great Basin in winter when a strong high develops and inversions progressively deepen with time due to a negative radiative imbalance over snow-covered ground.

I've seen it first hand. I live in Redmond Or and have seen highs projected at 35 when in real life they've been 20. The inversion and long nights really can't be accounted for enough sometimes. Two years ago an airmass came down from Canada that wasn't particularly cold, maybe 850's at -7 or so. But a few nights later it was below zero for lows and highs were in the upper teens. So it's fair to say that long nights and radiational cooling can go a long ways with an inversion.
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It's been brought up a few times on these forums on whether a warmer Arctic in winter would lead to a generally weaker, more meridional jet more prone to blocking patterns. Personally I see some validity to that view. I also agree with some of the current analysis and thinking re: a record warm Arctic/record low Nov Arctic sea ice has correlation to a weak polar jet, high latitude blocking and generally more extreme seasonal variability in the mid-latitudes. This seems likely to carry on into December and I feel that if the longwave pattern turns favorable across North America there's a very real risk of a historic arctic blast into the lower 48 this winter. Potentially something along the lines of 1983 or 1990 (not necessarily in December), or perhaps Jan 1979. Then again the stagnant pattern could always vary little from the present configuration promoting warmth over NA and cold across Eurasia for much of the winter...time will tell. I've never felt comfortable simply saying that a warm arctic means mild mid-latitudes, which seems to be a common refrain around here as of late. It doesn't need to be -40 in Yellowknife to have a healthy snowcover either. If the weak/meandering jet theory is true, along with a greater likelihood of blocking it's only a numbers game until a favorable blocking pattern develops and we score a major blast (either regionally or the entire CONUS).

 

I should mention cold airmasses easily form in situ over snow-covered expanses given the long nights and predominantly clear conditions across north-central North America in winter. I've seen the same effect in the Great Basin in winter when a strong high develops and inversions progressively deepen with time due to a negative radiative imbalance over snow-covered ground.

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?

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That's good not great. Talk about needing some retrogression. This map should be the definition of the need for it.

 

Well, it's showing an Aleutian/W Alaskan block building in, with a weaker ridge further south just off the west coast. That's a pattern signature that often comes right before a cold air mass dropping down along western North America, provided the west AK blocking high can build in strong enough and far enough east.

A forum for the end of the world.

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Funny how after all the hand-wringing, the modeling is trending right into your typical -ENSO/+QBO climatological progression.

 

Of course, that's party/mostly because the intraseasonal forcing is constructively interfering with/mirroring a Niña Cell..that will change in mid-December, where an EPO spike may be favored before forcing reaches 150E and beyond in late December, which should force another round of NPAC wave breaking.

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That's good not great. Talk about needing some retrogression. This map should be the definition of the need for it.

That's a classic -NAMT look. Retrogression would occur within approximately 3-4 days thereafter.

 

I also think that strong Hudson Bay ridge is crucial to obtaining most effective -NAMT assisted retrogression.

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Funny how after all the hand-wringing, the modeling is trending right into your typical -ENSO/+QBO climatological progression.

 

Of course, that's party/mostly because the intraseasonal forcing is constructively interfering with/mirroring a Niña Cell..that will change in mid-December, where an EPO spike may be favored before forcing reaches 150E and beyond in late December, which should force another round of NPAC wave breaking.

What if you had no hands and let's say they were blown off by a landmine. Call it a horrible Birthday present gone wrong. Would you use your feet to express concern or distress over the models clasping them together. That's a question perhaps for another day. Did someone spike my eggnog.

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That's good not great. Talk about needing some retrogression. This map should be the definition of the need for it.

 

It actually looks good in the 11 to 15 day period.  At day 10 you can see it's poised very nicely.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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00z GFS HR 42

Yeah, if we could go ahead and remove that 978mb low near the west-central Aleutians that would be great.

 

 

I'm not sure about that.  It's so far west it could easily dig up a ridge around 150W.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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I'm not sure about that.  It's so far west it could easily dig up a ridge around 150W.

If it bombed out sooner, it sure could. If it flattened the NPAC ridge sooner it could ride the northern periphery, then slide southeast into BC. The ridge would pop up in behind it. IF ALMOST COULD BE SHOULD BE NEARLY JUST ABOUT

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This is what the 12z ECMWF ensemble looks like at day 12.

 

 

post-222-0-82278900-1479959771_thumb.png

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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What if you had no hands and let's say they were blown off by a landmine. Call it a horrible Birthday present gone wrong. Would you use your feet to express concern or distress over the models clasping them together. That's a question perhaps for another day. Did someone spike my eggnog.

Lol, dude you're the best. :lol:

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HR 72

Model comparison 00z vs 18/12z

It almost looks like the offshore ridge is flattening a notch sooner, pivoting quicker. Hmmm....

 

 

A huge surface high complex right behind the one just south of the GOA also.  Looks like block building material.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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