ENSO Discussion

[MossMan]

Exactly... 24 hours of heavy snow does not change the very warm reality of last winter out there.

 

Every winter for the last 3yrs it seems like all I see on the news is the northeast trying to figure out where to put all the snow that has fallen, snow mountains in parking lots that don't finish melting until June, etc....just sick of it. Four straight suck fest winters in the Puget sound area...been too long. The east coast can suck it!

[Phil]

Exactly... 24 hours of heavy snow does not change the very warm reality of last winter out there.

Bingo. We actually had three moderate snow events last winter, all occurring in warmer than average patterns. So the media was treating it as another cold winter when in reality it was an incredible torch, unlike anything I've ever seen actually.

 

Sometimes our warmest winters are the snowiest, while our coldest winters can be the biggest failures in the snowfall department. All about storm track.

[Phil]

Every winter for the last 3yrs it seems like all I see on the news is the northeast trying to figure out where to put all the snow that has fallen, snow mountains in parking lots that don't finish melting until June, etc....just sick of it. Four straight suck fest winters in the Puget sound area...been too long. The east coast can suck it!

You can have the snowfall, haha. All I want is a normal winter that doesn't last into April for once. A mild January would be nice as well (that month is too cold for me).

[HighlandExperience]

[Phil]

[stuffradio]

Ever heard of karma? Be careful, man.

I don't know, we've been having karma the past few years in the snow department.

[Phil]

I don't know, we've been having karma the past few years in the snow department.

Mother Nature is a masterful troll. Destroying wx-weenie psyches is her primary goal in any winter. Comments like that are analogous to dangling red meat in front of a lion.

 

(Obviously I'm joking..mostly).

[HighlandExperience]

[Phil]

[TT-SEA]

Well, I think you can blame the Pacific Hadley cell for that, rather than bad luck. While the cell has been strengthening, expanding, and migrating poleward since the late 1970s, this trend accelerated in the late 1990s and really hasn't stopped since, though it is now (finally) slowing down.

 

 

Unless it reverses... we are not going to see any long-term improvement correct?   

 

Slow expansion is still expansion.  

[Phil]

Unless it reverses... we are not going to see any long-term improvement correct?

 

Slow expansion is still expansion.

Well, it will reverse eventually, and it could do so completely in under a decade. Based on our best observations and renanalyses, we've found significant variability/instability in the Hadley Cells over the last century+. The ongoing expansion is largely a natural cycle (AGW can explain 5-10%), so the big question isn't it'll snap back, but when?

[TT-SEA]

Well, it will reverse eventually, and it could do so completely in under a decade. Based on our best observations and renanalyses, we've found significant variability/instability in the Hadley Cells over the last century+. The ongoing expansion is largely a natural cycle (AGW can explain 5-10%), so the big question isn't it'll snap back, but when?

 

 

Right... but it will not happen this winter.   

[Phil]

Right... but it will not happen this winter.

Well, we don't know that for sure.

 

I'm just talking about the long term trends in the Hadley Cells. They vary significant on shorter timescales, almost to within the range of the long term/underlying trends.

[OKwx2k4]

Well, we don't know that for sure.

 

I'm just talking about the long term trends in the Hadley Cells. They vary significant on shorter timescales, almost to within the range of the long term/underlying trends.

This stuff ^ is why I read over on this side. I don't know a whole lot about the Hadley cells.

[Dan the Weatherman]

Socal and CA in general will probably continue to be in drought conditions until the Hadley Cell expansion finally reverses and it starts to shrink and retract southward enough to allow the jet and primary storm track to finally shift further south once again.

[snow_wizard]

Socal and CA in general will probably continue to be in drought conditions until the Hadley Cell expansion finally reverses and it starts to shrink and retract southward enough to allow the jet and primary storm track to finally shift further south once again.

 

Eh.  I'll be shocked if you don't do well this winter.

[Bryant]

Right... but it will not happen this winter.

You say this like you know what you're talking about

[snow_wizard]

Another thing people have to consider is the possibility of the Hadley cells expanding so much it actually ends up have an opposite effect of the cells only being expanded to a lesser degree.  Things like that happen with this stuff.  The Feb 1989 cold wave was actually initiated by a super positive AO.  The AO was so high it ended up allowing brutal cold to develop in Alaska which later plunged SE.

[TT-SEA]

You say this like you know what you're talking about

He said it could change within a decade.

 

Am I not kissing your a** enough Bryant??

[snow_wizard]

Another thing we need to remember is the Hadley cells were also expanded in the latter part of the 19th century.  It worked well for us then.  I think it all comes down to overall context (the overall setting these things are couched in).

[Phil]

Another thing we need to remember is the Hadley cells were also expanded in the latter part of the 19th century. It worked well for us then. I think it all comes down to overall context (the overall setting these things are couched in).

They were broad, true, but they were also weak. Essentially an inverted Hadley/Walker intensity ratio vs today, relatively speaking.

 

Today they're strong and broad/poleward.

[Front Ranger]

Another thing we need to remember is the Hadley cells were also expanded in the latter part of the 19th century. It worked well for us then. I think it all comes down to overall context (the overall setting these things are couched in).

Agreed. The variation in Hadley cells is not the primary driver of local snowfall trends, IMO.

[Phil]

Agreed. The variation in Hadley cells is not the primary driver of local snowfall trends, IMO.

I strongly, strongly, strongly disagree.

[Front Ranger]

I strongly, strongly, strongly disagree.

 

Is that why Spokane had their snowiest two year period on record from 2007-09?

[Phil]

Is that why Spokane had their snowiest two year period on record from 2007-09?

Is Spokane a borderline snow climate like SEA/PDX et al?

 

A few things here:

 

1) What timescale are you looking at? The Hadley Cells are quite unstable, and vary significantly on month-to-month scales, in both latitude and intensity, sometimes by 50-70% of the entire trend since the 1970s, though usually not quite to that extent.

 

2) The broadening Hadley Cells are reflected by a poleward migration of the subtropical highs, northern jet, and the horse latitude desert zones, as well as a weakened/wider ITCZ/equatorial convective integral. So, overall, this makes it more difficult for Arctic air to enter the PNW, and while this might not matter for less borderline locations like Spokane, it'll make a difference in the western lowlands.

 

It should also be noted that the Atlantic Hadley Cell hasn't reorganized in the same manner as the NPAC cell, and is subject to more significant absolute intraseasonal variability regardless, so these effects have been less noticeable in the Eastern US/Europe over recent decades (though other significant expressive shifts have occurred there).

[Front Ranger]

Is Spokane a borderline snow climate like SEA/PDX et al?

 

A few things here:

 

1) What timescale are you looking at? The Hadley Cells are quite unstable, and vary significantly on month-to-month scales, in both latitude and intensity, sometimes by 50-70% of the entire trend since the 1970s, though usually not quite to that extent.

 

2) The broadening Hadley Cells are reflected by a poleward migration of the subtropical highs, northern jet, and the horse latitude desert zones, as well as a weakened/wider ITCZ/equatorial convective integral. So, overall, this makes it more difficult for Arctic air to enter the PNW, and while this might not matter for less borderline locations like Spokane, it'll make a difference in the western lowlands.

 

It should also be noted that the Atlantic Hadley Cell hasn't reorganized in the same manner as the NPAC cell, and is subject to more significant absolute intraseasonal variability regardless, so these effects have been less noticeable in the Eastern US/Europe over recent decades (though other significant expressive shifts have occurred there).

 

That wasn't the issue at all from 2006-14. Was the Pacific Hadley Cell weaker in that period (which also happened to be dominated by -PDO/-ENSO)?

[snow_wizard]

 

 

2) The broadening Hadley Cells are reflected by a poleward migration of the subtropical highs, northern jet, and the horse latitude desert zones, as well as a weakened/wider ITCZ/equatorial convective integral. So, overall, this makes it more difficult for Arctic air to enter the PNW, and while this might not matter for less borderline locations like Spokane, it'll make a difference in the western lowlands.

 

 

A poleward migration of the subtropical high (if it's over the NE Pacific) would make it easier to get Arctic air into the NW.  Placement of the high is pretty crucial.

[snow_wizard]

This should help people see that a positive PNA November is often good for us.  This is a composite of Nov 500mb anoms during some of the greatest winters of the past 100 years.  The inverse of this is just about as convincing...low PNA Novembers leading to warm winters.

 

We have had an unprecedented number of Novembers with Arctic blasts during the past 35 years and at the same an unprecedented run of warm Januaries.

[snow_wizard]

Now for how those winters (Jan & Feb) turned out.  A 180 degree reversal.

 

 

[Phil]

That wasn't the issue at all from 2006-14. Was the Pacific Hadley Cell weaker in that period (which also happened to be dominated by -PDO/-ENSO)?

Well, I never said it'd preclude Arctic intrusion. There were several factors supporting Arctic intrusion during that time period, and the results would have been more impressive under an antecedent equatorward Hadley Cell regime.

 

All else ignored, Niña/-PDO favors a weaker but broader Pacific Hadley Cell, so there's more extratropical variability there in general. El Niño favors a stronger/tighter Pacific Hadley Cell overall.

[Phil]

Now for how those winters (Jan & Feb) turned out. A 180 degree reversal.

Want to guess how many of those were +PNA in both October and November?

 

Answer is two, and neither are very reflective of the pattern ongoing since late August. In -ENSO years where October featured a +PNA, those that flipped -PNA in November were much better winters in the PNW. It's not really debatable IMO.

[Phil]

A poleward migration of the subtropical high (if it's over the NE Pacific) would make it easier to get Arctic air into the NW. Placement of the high is pretty crucial.

It's not the subtropical high (itself) that breaks poleward during Arctic events, though.

[snow_wizard]

Want to guess how many of those were +PNA in both October and November?

 

Answer is two, and neither are very reflective of the pattern ongoing since late August. In -ENSO years where October featured a +PNA, those that flipped -PNA in November were much better winters in the PNW. It's not really debatable IMO.

 

Didn't you see the map I made?  The Novembers were obviously GOA trough, Western ridge, Eastern trough.  Sounds like +PNA to me.  Either that or I'm missing something.

[Phil]

Didn't you see the map I made? The Novembers were obviously GOA trough, Western ridge, Eastern trough. Sounds like +PNA to me. Either that or I'm missing something.

The point was, years that were +PNA in October, then flipped around to -PNA in November, were much better winters in the PNW than years that were +PNA in both October and November. No analog years w/ +PNAs in both October and November featured Arctic blasts during the following Januaries.

 

This October will finish with a fairly strong +PNA. Not a single day with a -PNA, actually. Statistically, you'd definitely want a flip into a -PNA during November, otherwise..well, we can cross that bridge if/when we come to it.

[Guest happ]

It's not the subtropical high (itself) that breaks poleward during Arctic events, though.

We want to suppress the subtropical high south to allow cooler/ wetter weather for the Southwest during winter. What do you see in terms of rainfall for California later this week and into November, Phil? 

[Phil]

We want to suppress the subtropical high south to allow cooler/ wetter weather for the Southwest during winter. What do you see in terms of rainfall for California later this week and into November, Phil?

 

I think California will actually cash in on some storminess during early and/or mid November, as another +WPO surge in concurrence with a completion of a strong EAMT cycle weakens/dislodges the standing convective wave @ 120E, weaking the Walker Cell and leading to another Niño-esque pattern for at least the first 10 days of November.

[James Jones]

Didn't you see the map I made?  The Novembers were obviously GOA trough, Western ridge, Eastern trough.  Sounds like +PNA to me.  Either that or I'm missing something.

I don't buy this November blast = crap January thing at all. I guess it depends on what you consider "major", but these are the biggest ones on record:

 

1896 (late January arctic intrusion, ridiculously cold March)

1900 (early January cold and snow)

1911 (late December/early January cold and snow

1955 (great winter, including cold in late January/early Feb)

1985 (long fake cold spell in December, torch January)

2006 (cold/snow in January)

2010 (cold spell in late December/early January that was close to awesomeness, late Feb blast)

 

Seems like every winter in our recorded history that had a major cold wave in November had something else later on, and all but one of them had something in January - the only exception was 85-86, but the extended November cold/snow and the December cold more than makes up for that. I guess we've never had a truly epic 1916/1950 type January after a November cold wave, but those kind of Januaries are very rare in the first place. I see no reason why you wouldn't want to see a major blast in November.

[Phil]

I don't buy this November blast = crap January thing at all. I guess it depends on what you consider "major", but these are the biggest ones on record:

 

1896 (late January arctic intrusion, ridiculously cold March)

1900 (early January cold and snow)

1911 (late December/early January cold and snow

1955 (great winter, including cold in late January/early Feb)

1985 (long fake cold spell in December, torch January)

2006 (cold/snow in January)

2010 (cold spell in late December/early January that was close to awesomeness, late Feb blast)

 

Seems like every winter in our recorded history that had a major cold wave in November had something else later on, and all but one of them had something in January - the only exception was 85-86, but the extended November cold/snow and the December cold more than makes up for that. I guess we've never had a truly epic 1916/1950 type January after a November cold wave, but those kind of Januaries are very rare in the first place. I see no reason why you wouldn't want to see a major blast in November.

Exactly. Plus +PNA Novembers during -ENSO tend to precede winters with weaker SE-ridges by frequency, not to mention more +PNA and/or +EPO.

 

Especially after a +PNA October..the -ENSO years with back to back +PNAs in Oct/Nov are (generally) sucky in the PNW.

[Deweydog]

I'm so confused.

 

I don't know whether to be happy or sad when it snows on Black Friday.

[BLI snowman]

I'm so confused.

 

I don't know whether to be happy or sad when it snows on Black Friday.

 

Will be lots of hilarious car accident mayhem if it does. Be happy.