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Author Topic: Winter 2017-18  (Read 22489 times)

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Offline Thundersnow

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Re: Winter 2017-18
« Reply #75 on: October 09, 2017, 06:40:08 AM »
here's what we know so far-

ENSO= most likely weak La NiŮa
QBO= moderately negative - complete change from last winters positive
Solar cycle- low

I think this combo promotes a highly variable winter here. The long range models center the coldest air in the northern plains- typical of La NiŮa. In combination with the moderately negative QBO should produce periods of northern blocking- which we couldn't buy the last 2 winters. I think we could actually see some potentially bitter cold periods followed by moderating periods in between- thus what I think will be a variable winter. If you add in a major SSW like January 1985- all bets are off for more prolonged cold. I think we see 2-3 winter threats this go around - perhaps more on the icy side.

Winter 1950-51 was very similar as far as a second La NiŮa winter following an albeit much weaker El NiŮo. Overall the winter was slightly above normal but had 2 major winter storms for Tennessee(and one minor). One was the great Appalachian November snow storm which blanketed the entire state with snow in late November followed by record cold. It remained cold into early December with one more sleet and snow event before warming back up all the way thorough January. In fact it was into the 60's and 70's for much of January before one of the most epic winter storms on state history occurred in late January and early February. An arctic air mass bled south and stalled over the apps- leaving major amounts of sleet and snow mostly over west and middle TN. Memphis and Nashville went down below -10 to end the event. There was one more cold period in mid march with 2 more snows statewide- one producing 7 inches at Nashville.

And keep in mind- October and early November 1950 torched before the variability started.

So all that in mind- we could end up normal or even above normal temps with quite a bit of variability in between.

I can ask my 90-y-o grandmother to this day about the winter of '51 and get a day by day retelling of the events. She also always talked about a Thanksgiving when it was mild out and then suddenly a cold wind blew in, and they had several inches of snow. I've figured out this was the Great Apps Storm of '50. But, the ice storm/blizzard of '51 is especially vivid for her.


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Offline BRUCE

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Re: Winter 2017-18
« Reply #76 on: October 09, 2017, 08:29:06 AM »
Any analog used beyond year 1885. Can be missleading.... due to climate change unfortunately....
Come on severe wx season...

Offline Crockett

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Re: Winter 2017-18
« Reply #77 on: October 09, 2017, 08:36:22 AM »
Any analog used beyond year 1885. Can be missleading.... due to climate change unfortunately....

No.

Offline Curt

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Re: Winter 2017-18
« Reply #78 on: October 09, 2017, 08:54:12 AM »
Any analog used beyond year 1885. Can be missleading.... due to climate change unfortunately....

1885? Lol

NOAA already accounts for climate change in their 30 year normal adjustments. Can you elaborate on rationale for 1985 being the basis and how would you compensate for climate change for a forecast? Respected Long range mets use lots of pre 1985 analogs to make a forecast by looking at SSTís in the pacific and Atlantic.

Post Merge: October 09, 2017, 11:13:58 AM
What worries me is that the cold spells in the eastern U.S. during the recent "good" winters (09-10, 13-14, 14-15) could just be flukes. While we were colder during those winters, much of the rest of the world was experiencing above normal temperatures.  It appears we were colder only because of the anomalous trough over our area caused by a warm pool of water off of northwestern North America for much of that time.  Is that the only way we can have a "normal" winter anymore?

I think what your referring to is the PDO (pacific decadonal oscillation). the positive PDO phase usually means a "warm blob" over the Northeast Pacific basin. All of the winters you mentioned did in fact have a positive PDO phase. I can also find tons of cold winters in TN where there was a negative PDO including 50-51, and the brutal winter of 17-18. I think the PDO will be fairly neutral this year.

PDO and QBO can fluctuate- but they are both overall trends and tend to stay in one phase for quite some time. A strong ENSO phase can totally overwhelm all other factors- including PDO and QBO- as it did in 2015-16. IMO- it takes awhile for climate to re adjust from something that large. There was a global spike in temps but now they're coming back down.
« Last Edit: October 09, 2017, 11:13:58 AM by Curt, Reason: Merged DoublePost »

Offline BRUCE

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Re: Winter 2017-18
« Reply #79 on: October 09, 2017, 11:31:39 AM »
Just like I said . Some are in denial....
Come on severe wx season...

Offline Curt

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Re: Winter 2017-18
« Reply #80 on: October 09, 2017, 11:36:04 AM »
Just like I said . Some are in denial....

Iíve never denied climate change. Thatís proven over and over.

Global warming is what I think youíre argument is based on and is a separate subject matter altogether. I was asking how did you choose 1985 as a basis and also- if you believe in global warming- how would you scientifically account for it in choosing an analog?

Offline JayCee

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Re: Winter 2017-18
« Reply #81 on: October 09, 2017, 11:59:16 AM »

Post Merge: October 09, 2017, 11:13:58 AM
I think what your referring to is the PDO (pacific decadonal oscillation). the positive PDO phase usually means a "warm blob" over the Northeast Pacific basin. All of the winters you mentioned did in fact have a positive PDO phase. I can also find tons of cold winters in TN where there was a negative PDO including 50-51, and the brutal winter of 17-18. I think the PDO will be fairly neutral this year.

PDO and QBO can fluctuate- but they are both overall trends and tend to stay in one phase for quite some time. A strong ENSO phase can totally overwhelm all other factors- including PDO and QBO- as it did in 2015-16. IMO- it takes awhile for climate to re adjust from something that large. There was a global spike in temps but now they're coming back down.

Thanks for the info!  I'm not well versed on the other oceanic phases out there.  Glad there are other factors that can influence our winter besides the "blob."  ;)
"For many years I was self-appointed inspector of snowstorms and rainstorms, and did my duty faithfully, though I never received one cent for it.." 
Henry David Thoreau

Offline Clarksville Snowman

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Re: Winter 2017-18
« Reply #82 on: October 09, 2017, 12:43:58 PM »
The climate is always changing and always has been. As far as global warming I don't buy it all. I look back at old record high and low temps and it is obvious that there have always been high and low swings in temp and weather. Nothing changes like the weather, stick around long enough and you will see plenty. I am certainly no expert and don't know as much as many on this board but I don't buy global warming at all. There have always been periods of warming and cooling. The world will end when God wants it too not because of some global warming. JMHO! ::popcorn:: ::cold:: ::snowman::

Offline Curt

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Re: Winter 2017-18
« Reply #83 on: October 09, 2017, 02:57:34 PM »


Courtesy of WeatherBell- this is a great graphic showing the difference between west based and east based La Nina. This will be an east based year.



Courtesy of WeatherBell, this is another great graphic when you add the east or west based QBO- positive and negative with low solar activity. The bottom left was basically last winter. This winter should look more like the top left.
« Last Edit: October 09, 2017, 03:00:11 PM by Curt »

Offline JayCee

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Re: Winter 2017-18
« Reply #84 on: October 09, 2017, 03:19:43 PM »
I'll leave the global warming debate on the shelf, and whether its man-made or not.  Arguments on both sides have merit, and I'll leave it at that.

What has happened in my lifetime is a definite warm "spell."  Growing up in the 80's, it wasn't too unusual to have temperatures plunging well below zero during winter. There were at least 4 years in that decade that had Arctic outbreaks of that caliber. It happened a few times in the 90's ('94 &'96), but outside of those winters, most in the 90's were mild to outright warm.  From 2000-2008 the mild to warm winters continued, except for 2003 that saw some "decent" cold weather.  After the recent few winters that began to show promise, and even one that saw a return to below zero temperatures (something that shouldn't be so infrequent --> http://www.weather.gov/jkl/2013warmwinterstreak), I was hoping that maybe a pattern change had taken place.  But the Super Nino of two years ago seems to have thrown a wrench into that, as we've been mostly above normal every month since (save for this past summer.)  I guess a lot hinges on the upcoming winter.  If its another torch-fest of well-above normal temperatures, then perhaps the recent colder winters were a fluke in an overall warm spell that has been continuing for over two decades now.  Graph below illustrates this well:

« Last Edit: October 09, 2017, 06:07:56 PM by JayCee »
"For many years I was self-appointed inspector of snowstorms and rainstorms, and did my duty faithfully, though I never received one cent for it.." 
Henry David Thoreau

Offline Curt

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Winter 2017-18
« Reply #85 on: October 09, 2017, 09:17:02 PM »
I'll leave the global warming debate on the shelf, and whether its man-made or not.  Arguments on both sides have merit, and I'll leave it at that.

What has happened in my lifetime is a definite warm "spell."  Growing up in the 80's, it wasn't too unusual to have temperatures plunging well below zero during winter. There were at least 4 years in that decade that had Arctic outbreaks of that caliber. It happened a few times in the 90's ('94 &'96), but outside of those winters, most in the 90's were mild to outright warm.  From 2000-2008 the mild to warm winters continued, except for 2003 that saw some "decent" cold weather.  After the recent few winters that began to show promise, and even one that saw a return to below zero temperatures (something that shouldn't be so infrequent --> http://www.weather.gov/jkl/2013warmwinterstreak), I was hoping that maybe a pattern change had taken place.  But the Super Nino of two years ago seems to have thrown a wrench into that, as we've been mostly above normal every month since (save for this past summer.)  I guess a lot hinges on the upcoming winter.  If its another torch-fest of well-above normal temperatures, then perhaps the recent colder winters were a fluke in an overall warm spell that has been continuing for over two decades now.  Graph below illustrates this well:



I wonít go into the global warming debate either since itís politicized

Another piece of the puzzle is the North Atlantic SST, called the AMO or Atlantic Multidecadanol Oscillation. Iím no expert but the warm phase is associated with warmer eastern winters and vice versa with the colder phase. The colder phases have a marked increase in arctic sea ice- which Iím going to assume increases surface area for arctic air masses. Here a good graphic:





You can trace the long colder and thus snowier winters of the 60ís, 70ís, and 80ís in a cold phase. Weíve been in a warm phase since 1996 - and most models flip it negative over the next 3-5 years. Perhaps thereís part of your answer although there have certainly been severe winters in the warm phase- just not as many as the cold.

Final thought here- one size doesnít fit all. Sometimes it seems one of the players- enso, qbo, pdo, and amo donít work out like we think due to one having prevalence over another. Itís not an exact science- but one we can at least make some assumptions about given past experience.
« Last Edit: October 09, 2017, 09:19:07 PM by Curt »

Offline Dyersburg Weather

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Re: Winter 2017-18
« Reply #86 on: October 09, 2017, 10:27:39 PM »
Some very good stuff Curt. You bring up some important factors imo. I like the east based QBO and I think the AMO is a really really big deal when it comes to winter weather.

Offline JayCee

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Re: Winter 2017-18
« Reply #87 on: October 10, 2017, 07:49:22 AM »
Appreciate the insight Curt!  I'll have to ask questions more often.   ::guitar::

"For many years I was self-appointed inspector of snowstorms and rainstorms, and did my duty faithfully, though I never received one cent for it.." 
Henry David Thoreau

Offline Clarksville Snowman

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Re: Winter 2017-18
« Reply #88 on: October 10, 2017, 07:57:30 AM »
Some very good stuff Curt. You bring up some important factors imo. I like the east based QBO and I think the AMO is a really really big deal when it comes to winter weather.
I concur great reads.

Offline JayCee

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Re: Winter 2017-18
« Reply #89 on: October 11, 2017, 08:03:40 AM »
After studying Curt's graphs further, it appears the Ohio and TN Valleys are in the battle zone between the colder north and the mild southeast with an east based La Nina.  One benefit of that will be plenty of precipitation, unlike the west-based La Nina that would probably bring a dry winter (like 2007), so that's a good thing.  As far as winter weather goes, I'd say Kentucky, and parts of northern and far western Tennessee would be in the best position, but this set-up screams "ICE" to me with many over-running events.  If that's they case, I hope it stays to our north.  I'll take plain-Jane rain over ice any day.

Thanks again for posting the good reads for the upcoming winter possibilities, Curt.  I've been doing some reading up on the QBO, AMO, and some of the lesser know acronyms out there.  It gave me something to do while at home recovering from a wicked cold.  Nothing on TV but more political ::poo::   ;D
"For many years I was self-appointed inspector of snowstorms and rainstorms, and did my duty faithfully, though I never received one cent for it.." 
Henry David Thoreau

 

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