Winter Predictions

[wx_statman]

The good news (from a PNW standpoint) is that the system's internal pendulum, so to speak, is on the other side now.

 

So there's only one way it can go, if pushed in the same manner it was back in 1977, and that's the other way. Or at least, that's my (oversimplified) opinion on the matter. It's probably a lot more complicated than that, in reality.

 

I'm wondering if we are indeed seeing some major reorganization that we will appreciate in later decades. Maybe the tropically-governed western ridge pattern from 2013-16 + the super Nino forced (or is forcing) a long-term, low frequency change. Much in the same way that the multi-year super Nina in the mid-1970's directly preceded the 1976-77 PDO flip. I've said it all year long, but this year has acted more like something out of the 1950s-80s here in the PNW. Pretty drastic departure from recent decades that started right off the bat with our cold January.

[Phil]

I'm wondering if we are indeed seeing some major reorganization that we will appreciate in later decades. Maybe the tropically-governed western ridge pattern from 2013-16 + the super Nino forced (or is forcing) a long-term, low frequency change. Much in the same way that the multi-year super Nina in the mid-1970's directly preceded the 1976-77 PDO flip. I've said it all year long, but this year has acted more like something out of the 1950s-80s here in the PNW. Pretty drastic departure from recent decades that started right off the bat with our cold January.

I generally agree with your line of thinking here. I feel like, in terms of the global system state, we're observing a setup that's highly analogous to the one observed at the conclusion of WWII into the middle 1940s, after the climax of the warmth that dominated the early 1940s (that multi-year +ENSO during the very early 1940s is also structurally similar to the recent one, FWIW).

 

There was a change in the seasonality of the Hadley/Walker system and PNA (tied to a shift in ENSO/PDO and a dampened seasonality of the Asian Monsoonal Cells) during the middle and later-1940s, which is where I think we'll be heading once again over the next decade or so.

 

*If* the climate system decides to obey its recent history (never a given, lol), even larger changes will take place right after the solar minimum El Niño of 2019/20. Watch the early 2020s!

[Brian_in_Leavenworth]

Interesting winter prediction here:  http://m.uploadedit.com/bbtc/1509722707103.pdf

 

A lot of talk about where the North Pacific Ridge will end up for most of the winter, and how to predict that.  A lot of that is based on QBO, etc.  

 

He has December, February, and March (Washington/North Idaho only for March) to be the coldest relative to average, and January about average.  Here is an excerpt, you will have to click on the link to see the whole thing and the images:

 

 

Forecast Discussion
 
 
North Pacific Pattern 
 
1. When the Jul to Oct AAM averages negative in concert with Cool ENSO conditions (Negative Neutral & La Nina), a 500mb high pressure ridge is strongly favored to exist in the North Pacific in the subsequent mean winter pattern (26 of 27 cases via AAM data back to 1958).
 
2. The location and configuration of the Cool ENSO North Pacific Ridge has a large influence on the weather pattern over North America.  
 
For the Cool ENSO winters that contained a North Pacific Ridge in the mean winter pattern (34 of 38 cases since 1949), I binned the winters based on the relative position of the ridge, i.e. whether the ridge was located in the ‘relative’ NW, NE, SW, or SE portion of the North Pacific."
 
 
 

 
 
 
 

 
 
 
3. The key takeaways from those images: a. The “North” North Pacific Ridge cases allow for meridional flow out of the Arctic on the east side of the ridge, with the U.S. temperature distribution having a general cool north / warm south configuration.
 
b. The “South” North Pacific Ridge cases are subject to west to east zonal flow on the north side of the ridge, cutting off the flow out of the Arctic, and have a general U.S. temperature distribution of cool west of the Rockies / warm east of the Rockies. 
 
4. The next obvious question is, how do we predict the specific location of the North Pacific Ridge during Cool ENSO winters?  
 
a. Anthony Masiello’s (Twitter: @antmasiello) findings from 2012 showed that “North” North Pacific Ridges are favored during La Nina / +QBO winters, while “South” North Pacific Ridges are favored during La Nina / -QBO winters.  Anthony noted that designating the winter QBO phase was heavily weighted toward the lower layers of the stratosphere (i.e. 40mb – 50mb).    
 
b. The problem this winter is that assigning a QBO designation in the lower stratosphere is more difficult than normal.  In the 40mb to 50mb layer, we will have a +QBO transitioning to -QBO.  The best comparisons among Cool ENSO years for the current QBO progression on the Berlin QBO chart would be the winters of 83-84 and 00-01.  The winters of 62-63 and 81-82 were also similar, but with an earlier progression into the QBO phase; while the winter of 11-12 was similar, but with a later progression into the QBO phase.
 
i. Neither the 83-84 nor the 00-01 winter featured a high pressure ridge in the North Pacific in a location that is typical of Cool ENSO winters.  Instead, both of these winters featured a similar mean pattern of NW Pac Trough / weak NE Pac Ridge / Central & Eastern U.S. Trough.

 ii. The 62-63 and 81-82 winters both featured a “North” North Pacific Ridge with negative height anomalies across large portions of the U.S. 
 
iii. The 11-12 winter featured a “South” North Pacific Ridge, a +AO/+NAO, and positive height anomalies across all of the U.S.
 
iv. When looking at Cool ENSO / -QBO winters, the 500mb pattern tends to differ based on whether the QBO is in the frontend of the -QBO cycle (i.e. either transitioning into the -QBO phase in the lower stratosphere as it will be this winter, or already in the early part of the -QBO phase in the lower stratosphere) the backend of the -QBO cycle.  The frontend -QBO winters tend to feature a “North” North Pacific Ridge and central U.S. trough, while the backend -QBO winters tend to follow the aforementioned correlation and contain a “South” North Pacific Ridge
 
 
 
 
c. Another factor I looked at for predicting the North Pacific Ridge location was the autumn 500mb pattern leading into winter.
 
i. The Oct-Nov pattern prior to “North” North Pacific Ridge winters tended to be absent of negative height anomalies in the Bering Sea, Alaska, and NW Canada.
 
ii. The Oct-Nov pattern prior to “South” North Pacific Ridge winters tended to contain solid negative height anomalies in the eastern Gulf of Alaska extending up into portions of the Bering Sea, Alaska, and/or NW Canada.
 
iii. Based on the current Oct 500mb pattern to date, and the ensemble forecast for the first half of November, this factor is also leaning toward a “North” North Pacific Ridge projection for winter since it doesn’t look like we are going to see solid negative anomalies in the mean pattern that extend from the Eastern Gulf of Alaska into the Bering Sea, Alaska, and/or NW Canada.  The forecasted pattern for the first half of November favors substantial ridging in Alaska and the Bering Sea.
 
d. Forecasting the West vs. East placement of the North Pacific Ridge
 
i. I looked at autumn tropical OLR and VP patterns during Cool ENSO years, but couldn’t ascertain any clear indicators to help with formulating a forecast for the west vs. east placement of the North Pacific Ridge. 
 
ii. Conventional thought may be to assume that a Central Pacific Nina favors a “West” North Pacific Ridge and that an East Pacific Nina favors an “East” North Pacific Ridge.  However, for the Central Pacific Ninas, I did not see the data to support this notion as there was an even mix.  For the East Pacific Ninas (like we will have this winter), maybe surprisingly, the opposite was true, as “West” North Pacific Ridges were more favored (11 of the last 14 cases).  In addition, when restricting this to East Pacific Cool ENSO winters that yielded a “North” North Pacific Ridge, 7 of the 8 cases produced a “North” North Pacific Ridge that was biased to the “West.”
 
iii. Finally, when looking at autumn 500mb patterns, wintertime “Northeast” North Pacific Ridges tended to feature positive height anomalies in the Eastern Gulf of Alaska and along the Canadian and U.S. west coast during months of Oct-Nov.  Since noteworthy positive anomalies are lacking in this region this autumn, this factor is also leaning toward a “West” North Pacific Ridge placement.  
 
 
Bottom Line: Based on the combination of an East Pacific Cool ENSO event, the frontend of the QBO phase, and the current & projected 500mb pattern this autumn, I favor the development of a “North” North Pacific Ridge that is variable, but biased to the northwest in the mean winter pattern.

[Front Ranger]

c. Another factor I looked at for predicting the North Pacific Ridge location was the autumn 500mb pattern leading into winter.

 

i. The Oct-Nov pattern prior to “North” North Pacific Ridge winters tended to be absent of negative height anomalies in the Bering Sea, Alaska, and NW Canada.

 

ii. The Oct-Nov pattern prior to “South” North Pacific Ridge winters tended to contain solid negative height anomalies in the eastern Gulf of Alaska extending up into portions of the Bering Sea, Alaska, and/or NW Canada.

 

iii. Based on the current Oct 500mb pattern to date, and the ensemble forecast for the first half of November, this factor is also leaning toward a “North” North Pacific Ridge projection for winter since it doesn’t look like we are going to see solid negative anomalies in the mean pattern that extend from the Eastern Gulf of Alaska into the Bering Sea, Alaska, and/or NW Canada.  The forecasted pattern for the first half of November favors substantial ridging in Alaska and the Bering Sea. 

 

Good stuff. Touches on a lot of the things Phil, myself, SW, and others have discussed this fall.

 

The section above is particularly interesting to me right now, since I've mentioned in my outlook how differences in the November pattern for the analog set tends to lead to differences in pattern timing in subsequent months. He's absolutely right that the fall pattern to this point has been dominated by high heights/-EPO in the Bering Sea/Alaska/NW Canada, but now we are seeing signs that the pattern will be shifting to +EPO and lower heights (at least for Alaska and NW Canada). However, from what I've seen, that is common following a -EPO period in the Oct 15 - Nov 15 time frame.

 

The overall mean for Oct/Nov will still probably end up with above normal heights for that region, and I agree with his conclusion that a further north Pacific ridge is favored for this winter. Especially for Dec/Jan.

[Phil]

Fascinating stuff there. Glad to see the myths associated with east-based Niñas refuted handily.

 

So much crap out there when it comes to east vs west based ENSO events, and their supposed "effects" on the pattern.

[Phil]

Part of me wonders if the December and January maps should be swapped. For the most part, I'm still getting a western trough/SE ridge type pattern in my January analogs, and vice versa for December.

[Front Ranger]

Part of me wonders if the December and January maps should be swapped. For the most part, I'm still getting a western trough/SE ridge type pattern in my January analogs, and vice versa for December.

 

I'm torn on it, too. I'm almost positive December will be cold for most of the northern tier, but I could easily see it favoring the East more than the West if things head in a 1989/1962/1995 direction over the next few weeks. At least for the first half of December. 2/3 of those winters were cold across most of the country in January, but Jan 1990 was mostly a blowtorch.

 

One thing going against the 1989 analog is solar. 1995 and 1962 to a lesser degree are better fits there.

[Phil]

I'm torn on it, too. I'm almost positive December will be cold for most of the northern tier, but I could easily see it favoring the East more than the West if things head in a 1989/1962/1995 direction over the next few weeks. At least for the first half of December. 2/3 of those winters were cold across most of the country in January, but Jan 1990 was mostly a blowtorch.

 

One thing going against the 1989 analog is solar. 1995 and 1962 to a lesser degree are better fits there.

Yeah, I agree. Maybe we split the difference and shift everything later by two weeks, lol.

 

I also think the timing of the U-wind flip @ 50mb will be play a role in the midwinter progression. Even a few weeks could theoretically make a difference.

[Front Ranger]

LR ensembles continue to paint a warm West/cold East/cold AK scenario later this month.

 

[snow_wizard]

Part of me wonders if the December and January maps should be swapped. For the most part, I'm still getting a western trough/SE ridge type pattern in my January analogs, and vice versa for December.

 

I'm feeling pretty sure December will have a cold event somewhere along the line, but there is good chance at least part of the month will be warmer.  In the years I've been looking at pretty much all of them had something good in December.

[snow_wizard]

 

Interesting winter prediction here:  http://m.uploadedit.com/bbtc/1509722707103.pdf

 

A lot of talk about where the North Pacific Ridge will end up for most of the winter, and how to predict that.  A lot of that is based on QBO, etc.  

 

He has December, February, and March (Washington/North Idaho only for March) to be the coldest relative to average, and January about average.  Here is an excerpt, you will have to click on the link to see the whole thing and the images:

 

 

Forecast Discussion

 

 

North Pacific Pattern 

 

1. When the Jul to Oct AAM averages negative in concert with Cool ENSO conditions (Negative Neutral & La Nina), a 500mb high pressure ridge is strongly favored to exist in the North Pacific in the subsequent mean winter pattern (26 of 27 cases via AAM data back to 1958).

 

2. The location and configuration of the Cool ENSO North Pacific Ridge has a large influence on the weather pattern over North America.  

 

For the Cool ENSO winters that contained a North Pacific Ridge in the mean winter pattern (34 of 38 cases since 1949), I binned the winters based on the relative position of the ridge, i.e. whether the ridge was located in the ‘relative’ NW, NE, SW, or SE portion of the North Pacific."

 

 

 

 

 

 

 

 

 

 

3. The key takeaways from those images: a. The “North” North Pacific Ridge cases allow for meridional flow out of the Arctic on the east side of the ridge, with the U.S. temperature distribution having a general cool north / warm south configuration.

 

b. The “South” North Pacific Ridge cases are subject to west to east zonal flow on the north side of the ridge, cutting off the flow out of the Arctic, and have a general U.S. temperature distribution of cool west of the Rockies / warm east of the Rockies. 

 

4. The next obvious question is, how do we predict the specific location of the North Pacific Ridge during Cool ENSO winters?  

 

a. Anthony Masiello’s (Twitter: @antmasiello) findings from 2012 showed that “North” North Pacific Ridges are favored during La Nina / +QBO winters, while “South” North Pacific Ridges are favored during La Nina / -QBO winters.  Anthony noted that designating the winter QBO phase was heavily weighted toward the lower layers of the stratosphere (i.e. 40mb – 50mb).    

 

b. The problem this winter is that assigning a QBO designation in the lower stratosphere is more difficult than normal.  In the 40mb to 50mb layer, we will have a +QBO transitioning to -QBO.  The best comparisons among Cool ENSO years for the current QBO progression on the Berlin QBO chart would be the winters of 83-84 and 00-01.  The winters of 62-63 and 81-82 were also similar, but with an earlier progression into the QBO phase; while the winter of 11-12 was similar, but with a later progression into the QBO phase.

 

i. Neither the 83-84 nor the 00-01 winter featured a high pressure ridge in the North Pacific in a location that is typical of Cool ENSO winters.  Instead, both of these winters featured a similar mean pattern of NW Pac Trough / weak NE Pac Ridge / Central & Eastern U.S. Trough.

 ii. The 62-63 and 81-82 winters both featured a “North” North Pacific Ridge with negative height anomalies across large portions of the U.S. 

 

iii. The 11-12 winter featured a “South” North Pacific Ridge, a +AO/+NAO, and positive height anomalies across all of the U.S.

 

iv. When looking at Cool ENSO / -QBO winters, the 500mb pattern tends to differ based on whether the QBO is in the frontend of the -QBO cycle (i.e. either transitioning into the -QBO phase in the lower stratosphere as it will be this winter, or already in the early part of the -QBO phase in the lower stratosphere) <VS.> the backend of the -QBO cycle.  The frontend -QBO winters tend to feature a “North” North Pacific Ridge and central U.S. trough, while the backend -QBO winters tend to follow the aforementioned correlation and contain a “South” North Pacific Ridge

 

 

 

 

c. Another factor I looked at for predicting the North Pacific Ridge location was the autumn 500mb pattern leading into winter.

 

i. The Oct-Nov pattern prior to “North” North Pacific Ridge winters tended to be absent of negative height anomalies in the Bering Sea, Alaska, and NW Canada.

 

ii. The Oct-Nov pattern prior to “South” North Pacific Ridge winters tended to contain solid negative height anomalies in the eastern Gulf of Alaska extending up into portions of the Bering Sea, Alaska, and/or NW Canada.

 

iii. Based on the current Oct 500mb pattern to date, and the ensemble forecast for the first half of November, this factor is also leaning toward a “North” North Pacific Ridge projection for winter since it doesn’t look like we are going to see solid negative anomalies in the mean pattern that extend from the Eastern Gulf of Alaska into the Bering Sea, Alaska, and/or NW Canada.  The forecasted pattern for the first half of November favors substantial ridging in Alaska and the Bering Sea.

 

d. Forecasting the West vs. East placement of the North Pacific Ridge

 

i. I looked at autumn tropical OLR and VP patterns during Cool ENSO years, but couldn’t ascertain any clear indicators to help with formulating a forecast for the west vs. east placement of the North Pacific Ridge. 

 

ii. Conventional thought may be to assume that a Central Pacific Nina favors a “West” North Pacific Ridge and that an East Pacific Nina favors an “East” North Pacific Ridge.  However, for the Central Pacific Ninas, I did not see the data to support this notion as there was an even mix.  For the East Pacific Ninas (like we will have this winter), maybe surprisingly, the opposite was true, as “West” North Pacific Ridges were more favored (11 of the last 14 cases).  In addition, when restricting this to East Pacific Cool ENSO winters that yielded a “North” North Pacific Ridge, 7 of the 8 cases produced a “North” North Pacific Ridge that was biased to the “West.”

 

iii. Finally, when looking at autumn 500mb patterns, wintertime “Northeast” North Pacific Ridges tended to feature positive height anomalies in the Eastern Gulf of Alaska and along the Canadian and U.S. west coast during months of Oct-Nov.  Since noteworthy positive anomalies are lacking in this region this autumn, this factor is also leaning toward a “West” North Pacific Ridge placement.  

 

 

Bottom Line: Based on the combination of an East Pacific Cool ENSO event, the frontend of the QBO phase, and the current & projected 500mb pattern this autumn, I favor the development of a “North” North Pacific Ridge that is variable, but biased to the northwest in the mean winter pattern.

 

 

Really good stuff there!

[snow_wizard]

2017-18 Winter Outlook

 

Based on differently weighted factors and trends, including: ENSO, QBO, PDO, AO, NAO, EPO, NPI/Jim's index, solar, and overall pattern progression. 

 

Top tier analogs: 1954, 1970, 1984, 1989, 1996, 2000

Second tier analogs: 1956, 1962, 1974, 1981, 1985, 2007

Third tier analogs: 1949, 1961, 1967, 1971, 1995, 2013

 

 

 

I agree with many of the years you have here.  Many of them have a lot going for them.  Really nice that so many of them were good winters.  The conclusion I'm coming to is if November is cold the winter is likely to be persistently cold with a good chance of all 3 winter months being cold.

[Front Ranger]

I agree with many of the years you have here.  Many of them have a lot going for them.  Really nice that so many of them were good winters.  The conclusion I'm coming to is if November is cold the winter is likely to be persistently cold with a good chance of all 3 winter months being cold.

 

I'm still not convinced November will end up cold, at least for the vast majority of the West. The latest Euro has joined the ensembles in showing a warm pattern developing for the West in the second half of the month.

[snow_wizard]

This is a rough overview of what I think the overall winter anomaly centers will look like.  I hope to fine tune this and come up with timing of the main cold snap(s) later on.

 

One thing that may happen this winter that we haven't seen for a while is a situation where an AR turns to snow as Arctic air approaches.

 

 

[snow_wizard]

I'm still not convinced November will end up cold, at least for the vast majority of the West. The latest Euro has joined the ensembles in showing a warm pattern developing for the West in the second half of the month.

 

That does remain to be seen.  Interestingly it looks pretty likely the heights / pressure over the NE Pacific will end up well above normal though.  Normally that would spell a cold month, but it didn't work out that way in years like 1990.

 

BTW it's pretty insane how nearly every one of your analogs is being reflected in the CPC analog composites the past few days.  It seems like we are at least on the right track with this one.

[ShawniganLake]

This is a rough overview of what I think the overall winter anomaly centers will look like. I hope to fine tune this and come up with timing of the main cold snap(s) later on.

 

One thing that may happen this winter that we haven't seen for a while is a situation where an AR turns to snow as Arctic air approaches.

When was the last time we saw a situation like that occur?

[Phil]

So far, Flatiron's forecast looks pretty good to me.

[Front Ranger]

So far, Flatiron's forecast looks pretty good to me.

 

We'll see. It definitely helps now that we're getting some clarity on the pattern developing for the second half of the month. I'll probably post some updated thoughts in the next few days based on that.

[snow_wizard]

When was the last time we saw a situation like that occur?

 

The last really good one here was December 1974.  Not sure about up your way.  The King of them all was Dec 1924.

[ShawniganLake]

The last really good one here was December 1974. Not sure about up your way. The King of them all was Dec 1924.

Interesting. Both of those months produced little to no snow up this way.

[snow_wizard]

Interesting. Both of those months produced little to no snow up this way.

 

Dry air must have moved in too quickly up there.  The Dec 1924 event was epic here.  A foot of snow in my area followed by brutal cold that lasted for many days.

[TigerWoodsLibido]

The last really good one here was December 1974. Not sure about up your way. The King of them all was Dec 1924.

I thought the late December, 2003 one was an AR that turned to snow at the tail end.

[ShawniganLake]

My forecast for SW British Columbia

 

 

 

Although there were a few mixed results with the analog packages, there is a very strong signal for a below average winter with well above average snowfall. Overall for the DJF period I am going with a mean temperature 1.0 to 1.5C below average with snowfall 150% of normal. (125-175% first flake to last flake). I would expect a minimum of 2 arctic intrusions, possibly more, and at least one of them being a notable event. ( Widespread low temps below -10C).

 

December is likely to be the second coldest month of the winter. Mean temp 1 to 1.5C below average. Snowfall most likely well above normal. There were a few years in my analogs that saw December end up fairly mild. In these instances we saw major cold and snow occur in January.

 

January will likely be the coldest month of the winter. Mean temperature 1.5 to 2.0C below average. Again there is a strong signal for above average snowfall but I believe December is slightly more likely to be a major snow month.

 

February will likely see temperatures start to moderate, possibly still chilly, but monthly mean should be closer to average. ~0.5C below average. Snowfall likely to be near to slightly above normal, but I believe February is our most likely month to be snowless. My thinking is that the troughing will be centered farther east this month. If we do see cold and snow it is likely to be more of a glancing shot, but that could open the door to a February 2014 type of snowfall.

[snow_wizard]

I thought the late December, 2003 one was an AR that turned to snow at the tail end.

 

It might have been down your way, but not up here.

[Jesse]

I thought the late December, 2003 one was an AR that turned to snow at the tail end.

 

You might be thinking of 11/19/03. I'm not sure it that would classify as a true AR, though. Definitely a strong baroclinic band.

[snow_wizard]

You might be thinking of 11/19/03. I'm not sure it that would classify as a true AR, though. Definitely a strong baroclinic band.

 

That one was interesting.  Could have been really wild if it had been later in the cold season.  Usually baroclinic bands are also ARs.

[TigerWoodsLibido]

You might be thinking of 11/19/03. I'm not sure it that would classify as a true AR, though. Definitely a strong baroclinic band.

It was definitely an Arctic air mass hitting us during an AR. I distinctly remember torrential rainfall for 2 days as the temp kept gradually lowering. It was the very end of December of 2003.

[SilverFallsAndrew]

December 1919 and 1924 were very similar here. All of NW Oregon had 18-24" of snow going into the 1919 blast. About 8-12" going into the 1924 blast.

[SilverFallsAndrew]

It was definitely an Arctic air mass hitting us during an AR. I distinctly remember torrential rainfall for 2 days as the temp kept gradually lowering. It was the very end of December of 2003.

 

No that was cold air being drawn into the backside of a departing low. 

[BLI snowman]

It was definitely an Arctic air mass hitting us during an AR. I distinctly remember torrential rainfall for 2 days as the temp kept gradually lowering. It was the very end of December of 2003.

 

Maybe thinking of December 29, 2003 which was another rain to snow event for the Willamette Valley.

[Front Ranger]

GFS and ensembles generally want to blowtorch the entire West, while the mid/long range pattern on the latest Euro and EPS has the warmth centered more towards the middle of the country. Either way, looks like the NE is in for some very cool weather over the next couple of weeks.

[Phil]

GFS and ensembles generally want to blowtorch the entire West, while the mid/long range pattern on the latest Euro and EPS has the warmth centered more towards the middle of the country. Either way, looks like the NE is in for some very cool weather over the next couple of weeks.

We're due. Been an epic torch since the super niño.

[snow_wizard]

We're due. Been an epic torch since the super niño.

 

The torch we had during the Nino was inane.  I absolutely hated it.

[Front Ranger]

Thanks. Eager to see how November unfolds.

 

If you held a gun to my head now and demanded I provide a prediction for the month (this happens a lot), I'd lean towards it turning pretty warm for the West the second half of November, leading to an above normal month overall.

 

 

I'm torn on it, too. I'm almost positive December will be cold for most of the northern tier, but I could easily see it favoring the East more than the West if things head in a 1989/1962/1995 direction over the next few weeks. At least for the first half of December. 2/3 of those winters were cold across most of the country in January, but Jan 1990 was mostly a blowtorch.

 

One thing going against the 1989 analog is solar. 1995 and 1962 to a lesser degree are better fits there.

 

Circling back to these thoughts. Most guidance is indicating that the somewhat warm pattern that has started developing for the West over the past week will intensify and spread the second half of the month.

 

 

If the long range EPS and GEFS are to be believed, there is very little chance that most of the West ends up cool or even close to normal overall for November. Let's assume that plays out.

 

This would narrow down my primary analogs going forward to: 1954, 1962, 1970, 1981, 1989, 1995, and 2007. Rolling those years forward to December yields:

 

 

Worth noting, though, that while the overall composite is warm, a couple of the years were not for much of the West: 1970 and 2007. 1954 was normal-ish.

 

Rolling the analogs further forward to January reveals a cold look for much of the country, with the main cold likely centered West.

 

[Phil]

Great analysis, man. Nice call on the November warm-up too.

 

All of those years had a coherent -PNA episode at some point during the midwinter period, so that's a pretty strong signal there as well.

[Front Ranger]

Great analysis, man. Nice call on the November warm-up too.

 

All of those years had a coherent -PNA episode at some point during the midwinter period, so that's a pretty strong signal there as well.

 

Thanks. Mid winter is certainly looking more promising for major cold chances across the CONUS. 

 

For our PNW friends, I think it's worth mentioning that only one of the analog years saw any cold weather of note before Christmas (1970, which featured a little cold snap with some lowland snow at the beginning of December, and then a more moderate cold wave with some lowland snow the week leading up to Christmas). 1995 did feature a couple minor cold spells, and 2007 had several bouts with chilly, low snow levels. The rest of the years were mostly warm the first half of the month, and somewhat cooler the second half.

 

But then in January, several years had significant cold waves the first half of the month (1963, 1971, 1982), and then a couple delivered later in the month (1963 again, 1996). 1955 and 2008 both had chilly weather with some lowland snow and near-misses for major cold. The only complete dud was Jan 1990...but then went on to probably the best overall February for the PNW lowlands in the past several decades, as far as persistent cold and snow.

 

So if the next few weeks do end up torching, there's plenty of reason to be hopeful for good things later. 

[Kayla]

While the SW looks to clearly run above average for the month of November, it's pretty clear that the northern tier will end up below average for the month. I'm curious what the analogs pick up on for D/J/F with a warm November in the SW but a cold northern tier? I'm still liking 1996 IMO...

 

 

 

 

[Front Ranger]

While the SW looks to clearly run above average for the month of November, it's pretty clear that the northern tier will end up below average for the month. I'm curious what the analogs pick up on for D/J/F with a warm November in the SW but a cold northern tier? I'm still liking 1996 IMO...

 

Looking at the modeled pattern going forward, my guess would be only parts of MT/ND will end up below normal by end of month. Probably a much smaller area of below normal anomalies across the northern tier than what you see now.

 

That being said, 1996 did have a similar temp pattern across the U.S. to what we're seeing this month. It was high on my original list of analogs and I still think it's solid, though I'd put some other years ahead of it at this point.

 

 

1970, 1995, and 2007 were also cooler across the northern tier, with a similar temp profile.

[Front Ranger]

FWIW, if you just roll those 4 years forward, this is what you get for Dec and Jan.

 

 

 

Almost everything points to a very cold winter in the northern Plains, and probably northern Rockies as well.

[Kayla]

Looking at the modeled pattern going forward, my guess would be only parts of MT/ND will end up below normal by end of month. Probably a much smaller area of below normal anomalies across the northern tier than what you see now.

 

That being said, 1996 did have a similar temp pattern across the U.S. to what we're seeing this month. It was high on my original list of analogs and I still think it's solid, though I'd put some other years ahead of it at this point.

 

1996.png

 

1970, 1995, and 2007 were also cooler across the northern tier, with a similar temp profile.

 

Good stuff, thanks! I don't see a way except for maybe far western MT overcoming a -10 to -15 temp anomalies even with the going forecasts though. I would expect the Nov 1996 map will end up pretty darn close to reality come month end this year.

 

Interesting enough, 1970, 1995 and 2007 were all coming off of weak to moderate Niños the previous winters. The 1996 analog is the only second year Niña on that list...