Jump to content

Welcome to our forums!

Sign In or Register to gain full access to our forums. By registering with us, you'll be able to discuss, share and private message with other members of our community.

Welcome!

Thanks for stopping by the Weather Forums! Please take the time to register and join our community. Feel free to post or start new topics on anything related to the weather or the climate.


Photo

Winter Predictions

- - - - -

  • Please log in to reply

#51
Black Hole

Posted 23 October 2017 - 12:02 PM

Black Hole

    Daily Contributor

  • Admin
  • 1561 posts
  • LocationBountiful, Ut 84010 ~4575ft

Interesting stuff, thanks. I'm not familiar with mesoscale dynamics over the Plains. I'd just naturally expect a very well mixed lower boundary layer when frigid Arctic air runs into the Gulf Coast States. Doesn't mean I'm correct in that kind of thinking, though.

I spend some time most years in Texas and I've seen it the last two times in winter when I have gone down where the lower level cold will move out ahead of the upper level cold. The lower boundary is probably well mixed, but due to its high density it seems to be able to hold together and remain separate from the warmer air above it.

And to speak to Front Rangers point. The terrain allows for some cold air damming which accelerates the lower level flow faster than it would otherwise move. 


  • Phil likes this

BS Atmospheric Science University of Utah May 2015

PhD Candidate Atmospheric Sciences

 

--Emphasis on: Forecasting, Mountain Weather, Numerical Weather Prediction, Data Assimilation

 

Winter 2017/2018

Dec 4: 3.2", 16: 0.9", 20: 2.1", 23: 1.5", 25: 4.6"

Jan 6: 1.5", 20: 10.8", 25: 1.5"

Feb 19: 8.6", 20: 2.4", 23: 7.1", 25: .5"

Mar 4: 13", 15: 1.8", 17: 5.3", 25: 4.2"

April 12: 1", 17: 1.3"

Total: 69.3"

 

 

Winter 2016/17 Snow:
Nov 17: 3.2", 23: 1.6", 28: 9.2" (14)

Dec 1: .5", 16: 2.5", 25: 13" (16)

Jan 2: 5", 3: 2.4", 4: 7.7", 12: 1", 19: 1.2", 21: 13", 23: 6", 24: 1", 25: 3.7", 26: 2.5" (43.5) 

Feb 11: .5", 23: 6.5", 27: 4.5" (13.5)

Mar 5: 5.5" (5.5)

Apr 8: 2", 9: 1.8" (3.8)

May 17: 1" (1)
Total: 96.3"

Lowest Temp: 2F


#52
crf450ish

Posted 23 October 2017 - 01:31 PM

crf450ish

    Cool Anomalies

  • Members
  • PipPipPipPipPip
  • 1030 posts
  • LocationStevens County, WA

I'm betting you get colder than -4 this winter. This one is screaming big blast.


I hope so. Coldest I’ve ever experienced was in Epping, ND in Nov of 2013...., 15 below. As far as my area that I live in, Chewelah holds the record for 33 below in the 70’s (as far as I know). That’s effectively 30 miles due east of my doorstep. I’d like some of that cold. I wanna make a YouTube vid of my kids shooting their super soakers in that kind of cold weather. More like shooting steam 😂

#53
SilverFallsAndrew

Posted 23 October 2017 - 03:18 PM

SilverFallsAndrew

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15091 posts
  • LocationSilverton, OR

I spend some time most years in Texas and I've seen it the last two times in winter when I have gone down where the lower level cold will move out ahead of the upper level cold. The lower boundary is probably well mixed, but due to its high density it seems to be able to hold together and remain separate from the warmer air above it.

And to speak to Front Rangers point. The terrain allows for some cold air damming which accelerates the lower level flow faster than it would otherwise move. 

 

From my experience living in Oklahoma you are correct. The lower level cold air usually moves well ahead of the upper level cold. 


  • Black Hole likes this

Snowfall

2017-18: 30.3"

2016-17: 49.2"

2015-16: 11.75"

2014-15: 3.5"
2013-14: 11.75"
2012-13: 16.75"
2011-12: 98.5"

 

It's always sunny at Winters Hill! 

 


#54
TigerWoodsLibido

Posted 23 October 2017 - 03:58 PM

TigerWoodsLibido

    Daily Contributor

  • Members
  • PipPipPipPipPip
  • 2246 posts
  • LocationSpringfield, OR 502'
Yup. That's why NE Texas experiences a lot of ice storms because that lower level air is indeed colder than aloft as you say.

Springfield, Oregon cold season 18-19 Stats:

Coldest high: 54 (Oct 5)
Coldest low: 35 (Oct 15)
Total snowfall: 0"
Last accumulating snowfall: February 21-22, 2018
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 1985

Personal Stats:

Last accumulating snowfall : March 6, 2017
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 2008

My Twitter @353jerseys4hope


#55
OKwx2k4

Posted 24 October 2017 - 01:34 AM

OKwx2k4

    Advanced Member

  • Members
  • PipPipPipPipPipPip
  • 3441 posts

From my experience living in Oklahoma you are correct. The lower level cold air usually moves well ahead of the upper level cold.


I live in practically the best cold air damming location in Oklahoma and this is an accurate description.

#56
Phil

Posted 24 October 2017 - 09:04 AM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.
I always though cold air damming had to do with trapping low level cold, as opposed to funneling it in. At least that's how meteorologists view it around here.

Cold air takes forever to make it over the Appalachian mountains thanks to downsloping/adiabatic warming, but it's also very slow to evacuate, for the same reason(s). That's what we usually refer to as "cold air damning", as the mountains tend to "dam" the cold air in, much like a river dam does water.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#57
Front Ranger

Posted 24 October 2017 - 09:09 AM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

I always though cold air damming had to do with trapping low level cold, as opposed to funneling it in. At least that's how meteorologists view it around here.

Cold air takes forever to make it over the Appalachian mountains thanks to downsloping/adiabatic warming, but it's also very slow to evacuate, for the same reason(s).

 

Same here.


  • Phil likes this

Cool anomalies soothe the soul.


#58
TigerWoodsLibido

Posted 24 October 2017 - 09:43 AM

TigerWoodsLibido

    Daily Contributor

  • Members
  • PipPipPipPipPip
  • 2246 posts
  • LocationSpringfield, OR 502'

I always though cold air damming had to do with trapping low level cold, as opposed to funneling it in. At least that's how meteorologists view it around here.

Cold air takes forever to make it over the Appalachian mountains thanks to downsloping/adiabatic warming, but it's also very slow to evacuate, for the same reason(s). That's what we usually refer to as "cold air damning", as the mountains tend to "dam" the cold air in, much like a river dam does water.

 

Same thing happens in the western Willamette Valley when we are in the icebox and a low pressure system overruns it.  The eastern outflow from the Columbia River Gorge toward the low center creates a cold air dam that pushes the column of cold air in the west valley higher, so as to delay or outright prevent freezing rain or sleet developing (such as what happened in 2008).  This is why places like Lebanon, Silverton and areas in the east valley have the warm nose affect them sooner with freezing rain/sleet or simply rising above freezing in the lower levels sooner than, say, McMinnville, Grand Ronde, Dallas, Monmouth/Independence, and sometimes even Philomath/Corvallis


  • Phil likes this

Springfield, Oregon cold season 18-19 Stats:

Coldest high: 54 (Oct 5)
Coldest low: 35 (Oct 15)
Total snowfall: 0"
Last accumulating snowfall: February 21-22, 2018
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 1985

Personal Stats:

Last accumulating snowfall : March 6, 2017
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 2008

My Twitter @353jerseys4hope


#59
Chris

Posted 31 October 2017 - 01:55 PM

Chris

    Community Mod

  • Admin
  • 1189 posts
  • LocationOregon Coast Range 1000'

Here's Mark Nelsen's prediction, from his KPTV blog

 

screenshot_191.png

 

screenshot_192.png

 

screenshot_193.png

screenshot_195.png



#60
Kayla

Posted 31 October 2017 - 06:10 PM

Kayla

    Advanced Member

  • Members
  • PipPipPipPipPipPip
  • 2686 posts
  • LocationBozeman, MT

Here's Mark Nelsen's prediction, from his KPTV blog

 

He REALLY went out on a limb with this forecast... :lol:


Cold Season 2018/19:

Total snowfall: 11.0"
Highest daily snowfall: 7.0"

Highest snow depth: 7.0"

Coldest high: 36.1º
Coldest low: 18.0º

Number of subzero days: 0

 

Personal Weather Station on Wunderground: https://www.wundergr...OZEM152#history


#61
Phil

Posted 31 October 2017 - 08:29 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.
How is 2016/17 on Mark's Niña list, while 2008/09 isn't? The system state was easily more Niña-esque overall in 2008/09 than it was last winter. Like, it's not even f**king close.
  • Front Ranger likes this
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#62
TigerWoodsLibido

Posted 31 October 2017 - 09:03 PM

TigerWoodsLibido

    Daily Contributor

  • Members
  • PipPipPipPipPip
  • 2246 posts
  • LocationSpringfield, OR 502'

Mark Nelsen relies way too much on the GFS and MOS guidance.  He was the worst forecaster for the 2008 event as he completely ignored the effects of the east wind cold air dam that kept the west valley in the snow much longer and it did not get above freezing while his forecast called for temps to rise to 48 degrees.  We didn't see the 40s for at least 3-4 days after that storm.  Easily had over 2' of snow on the ground in the west valley.  He made the same mistake last year in one of the early January events as Monmouth stayed in the snow for virtually the entire time Portland was being entombed in ice.


  • Phil likes this

Springfield, Oregon cold season 18-19 Stats:

Coldest high: 54 (Oct 5)
Coldest low: 35 (Oct 15)
Total snowfall: 0"
Last accumulating snowfall: February 21-22, 2018
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 1985

Personal Stats:

Last accumulating snowfall : March 6, 2017
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 2008

My Twitter @353jerseys4hope


#63
Front Ranger

Posted 31 October 2017 - 10:07 PM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

How is 2016/17 on Mark's Niña list, while 2008/09 isn't? The system state was easily more Niña-esque overall in 2008/09 than it was last winter. Like, it's not even f**king close.

 

Agreed. 2008-09 produced a bunch of snow, though, so it didn't fit his weak/moderate Nina narrative.


  • Phil likes this

Cool anomalies soothe the soul.


#64
TT-SEA

Posted 01 November 2017 - 07:12 AM

TT-SEA

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 34286 posts
  • LocationNorth Bend WA

Mark Nelsen relies way too much on the GFS and MOS guidance.  He was the worst forecaster for the 2008 event as he completely ignored the effects of the east wind cold air dam that kept the west valley in the snow much longer and it did not get above freezing while his forecast called for temps to rise to 48 degrees.  We didn't see the 40s for at least 3-4 days after that storm.  Easily had over 2' of snow on the ground in the west valley.  He made the same mistake last year in one of the early January events as Monmouth stayed in the snow for virtually the entire time Portland was being entombed in ice.

 

I have seen Mark talk many times about how scouring out cold air can be very slow in the Portland area with east wind events and how the models often struggle in that situation.   Its really difficult to forecast.   He certainly understands how it works... he lives in the Gorge.   

 

Its tricky and destined to cause forecasting problems down there.   I have seen other times when he assumed it would stay cold and snowy and then it gets above freezing and there is nothing but cold rain.



#65
Jesse

Posted 01 November 2017 - 11:24 AM

Jesse

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 25498 posts
  • LocationEast Vancouver, WA (300')

He REALLY went out on a limb with this forecast... :lol:

 

He's gotten older and crankier over the years. Summer warmth is by far his favorite thing to forecast these days.



#66
Deweydog

Posted 01 November 2017 - 03:26 PM

Deweydog

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 17277 posts
  • LocationHockinson, WA
Mark has developed a boring accuracy bias over the years. Definitely doesn't play well with the weenies. Oh the good ol' days of the 1990's when he'd go full nuclear with his seven day after a couple tasty GFS runs... Even in 2008 he I believe had at one point a seven day with at least five straight highs in mid 20'$. That's money!!!

All roads lead to Walgreens.  


#67
Front Ranger

Posted 01 November 2017 - 06:40 PM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

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

 

More difficult winter outlook than normal, due to a lack of analogs without major holes, and fairly different timing of patterns depending on if November ends up warm or cold in the West.

 

IF November ends up cold in the West, I'd strongly favor 1956, 1961, 1971, 1985, and 2000. 

 

IF November ends up warm, I'd favor 1954, 1962, 1989, 1995, 2007 and 2013.

 

December

 

Strong signal for cold across the northern tier of the U.S., with the cold anomalies centered in the northern plains/upper Midwest. Warm across much of the southern tier. Anomalously high heights over the Aleutians, with the polar vortex likely spending some time in northern Canada. -1 to -3 anomalies predicted in the PNW, with northern areas likely to see the greatest cold. Decent chance this is the coldest month of the winter for New England.

 

January

 

Good signal for cold throughout the West, centered in the interior West/Great Basin. Expect NE Pacific ridging near the sweet spot for Arctic blasts offshore of North America, with the intensity of said blasts depending on amplification of the ridge. -2 to -5 anomalies predicted for the PNW. Under the influence of -EPO and perhaps weak -NAO, the rest of the country looks cool to near normal. Some moderation likely in the northern Plains.

 

February

 

Two main signals emerge this month: strong SE ridging, and a weakening of the -EPO, with strong ridging alternating between offshore and over the West coast. Expect most of the West to be below normal once again, but with the coldest anomalies shifting back to the northern plains. Warmth likely extends all the way up the east coast. Much of Canada is VERY cold. -1 to -3 for the PNW.

 

March

 

Hardest month to read by far, with not much in the way of meaningful signals. Moderation looks likely for the middle of the country, though the Northwest could easily remain cool. There is still some ridging in the NE Pacific, but also increasing likelihood of +EPO. The entire southern tier should be warm, especially the SE. 0 to -2 for the PNW.

 

Winter Temperature:

 

Attached File  winterforecast.png   188.03KB   0 downloads

 

Precipitation:

 

There is an above average chance that this winter ends up drier than normal for much of the West Coast and northern plains. Near normal precip for the Great Basin/Rockies, and wetter than normal storm track along southern plains and lower Midwest, which should be the battle ground between warmth/cold.


  • Phil and Kayla like this

Cool anomalies soothe the soul.


#68
Phil

Posted 01 November 2017 - 06:46 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.
Great analysis, man. Looks good to me.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#69
TigerWoodsLibido

Posted 01 November 2017 - 09:11 PM

TigerWoodsLibido

    Daily Contributor

  • Members
  • PipPipPipPipPip
  • 2246 posts
  • LocationSpringfield, OR 502'

Would be pretty great for all of us in the PNW


Springfield, Oregon cold season 18-19 Stats:

Coldest high: 54 (Oct 5)
Coldest low: 35 (Oct 15)
Total snowfall: 0"
Last accumulating snowfall: February 21-22, 2018
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 1985

Personal Stats:

Last accumulating snowfall : March 6, 2017
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 2008

My Twitter @353jerseys4hope


#70
Front Ranger

Posted 02 November 2017 - 05:29 AM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

Great analysis, man. Looks good to me.

 

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.


  • Phil likes this

Cool anomalies soothe the soul.


#71
Phil

Posted 02 November 2017 - 08:54 AM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.

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.


Interesting take. You might be right, assuming that anticyclone continues to retrograde into the Siberia/WPO area (which would fit with climo). I've been too busy to do much analysis on the pattern progression lately, unfortunately, so I have no idea what will happen.

I do see something in mid/late December, when the ongoing poleward propagation of AAM comes to a head over the Arctic/NAM domain, but other than that, I'm not sure.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#72
Kayla

Posted 02 November 2017 - 09:40 AM

Kayla

    Advanced Member

  • Members
  • PipPipPipPipPipPip
  • 2686 posts
  • LocationBozeman, MT

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.

 

Thanks for sticking your neck out there and putting together this forecast. Looks great!

 

I'm honestly still liking the 1996 analog. Pattern progression has been pretty spot on for at least out here. Slightly below average October, below average November with above average precip and an average December with above average precip.

 

I'm thinking the west sees a brief ridge mid month before we go back into a similar pattern that we're in now by the end of the month.


  • Front Ranger likes this

Cold Season 2018/19:

Total snowfall: 11.0"
Highest daily snowfall: 7.0"

Highest snow depth: 7.0"

Coldest high: 36.1º
Coldest low: 18.0º

Number of subzero days: 0

 

Personal Weather Station on Wunderground: https://www.wundergr...OZEM152#history


#73
BLI snowman

Posted 02 November 2017 - 10:40 AM

BLI snowman

    Lacking H20

  • Members
  • PipPipPipPipPipPipPip
  • 7313 posts
  • LocationBlythe, CA

I think we torch at least one month this winter. December seems like it might be the best bet.


  • Deweydog likes this

#74
Front Ranger

Posted 02 November 2017 - 11:36 AM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

I think we torch at least one month this winter. December seems like it might be the best bet.

 

I agree that if a month ends up warm, December is most likely. However, if November ends up pretty warm, I'd say it's pretty unlikely. Hardly any examples of that with -ENSO.


Cool anomalies soothe the soul.


#75
BLI snowman

Posted 02 November 2017 - 12:05 PM

BLI snowman

    Lacking H20

  • Members
  • PipPipPipPipPipPipPip
  • 7313 posts
  • LocationBlythe, CA

I agree that if a month ends up warm, December is most likely. However, if November ends up pretty warm, I'd say it's pretty unlikely. Hardly any examples of that with -ENSO.

 

Also seems less and less likely judging from the next couple weeks.



#76
TigerWoodsLibido

Posted 02 November 2017 - 12:16 PM

TigerWoodsLibido

    Daily Contributor

  • Members
  • PipPipPipPipPip
  • 2246 posts
  • LocationSpringfield, OR 502'

I agree that if a month ends up warm, December is most likely. However, if November ends up pretty warm, I'd say it's pretty unlikely. Hardly any examples of that with -ENSO.

 

We will be in the warm sector of the system next week and in the 50s so I guess that's right about normal.  Still a lot of November left.


Springfield, Oregon cold season 18-19 Stats:

Coldest high: 54 (Oct 5)
Coldest low: 35 (Oct 15)
Total snowfall: 0"
Last accumulating snowfall: February 21-22, 2018
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 1985

Personal Stats:

Last accumulating snowfall : March 6, 2017
Last sub-freezing high: Jan 13, 2017 (31)
Last White Christmas: 2008

My Twitter @353jerseys4hope


#77
Front Ranger

Posted 02 November 2017 - 01:39 PM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

Also seems less and less likely judging from the next couple weeks.

 

A lot of uncertainty just past day 6 at this point.


Cool anomalies soothe the soul.


#78
Phil

Posted 02 November 2017 - 03:27 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.
Looking at the residual +QBO/westerlies at 50mb, and the huge swath of easterlies downwelling above it, I'm having a very hard time believing we won't see a major, low-frequency pattern shake-up sometime in December, perhaps around the winter solstice.

When the lower stratosphere flips modes, I suspect this NPAC wavetrain (poleward Aleutian anticyclone/-EPO) will either reshuffle somehow or collapse equatorward (from a seasonal-scale standpoint) as the convection/Z-Cells begin to respond. Exactly when/how this process unfolds is still unclear to me, however I'm target the period around the winter solstice, for the time being.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#79
Phil

Posted 02 November 2017 - 03:30 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.
Looking aloft in the QBO/SAO boundary, the next period of downwelling should occur towards the winter solstice, at which point the lower stratosphere will join the upper stratosphere in the -QBO boundary state configuration. Whether coincidently or not, this is perfectly timed to the completing of the poleward AAM propagation cycle that began in September.

I'd give the westerlies @ 50mb another 7-8 weeks to live.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#80
Phil

Posted 02 November 2017 - 03:33 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.
So, pattern wise, something big/anomalous should go down around the winter solstice/holiday period. Exactly what that may be, and how it unfolds, is still debatable (IMO).
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#81
wx_statman

Posted 02 November 2017 - 06:47 PM

wx_statman

    Advanced Member

  • Members
  • PipPipPipPipPipPip
  • 4540 posts
  • LocationPortland, OR

Looking aloft in the QBO/SAO boundary, the next period of downwelling should occur towards the winter solstice, at which point the lower stratosphere will join the upper stratosphere in the -QBO boundary state configuration. Whether coincidently or not, this is perfectly timed to the completing of the poleward AAM propagation cycle that began in September.

I'd give the westerlies @ 50mb another 7-8 weeks to live.

 

Very interesting. We haven't seen a flip to -QBO @ 50mb in the Dec-Jan timeframe since January 1977. That was of course during the great reorganization of the Pacific background state.


  • Phil likes this

#82
Phil

Posted 02 November 2017 - 07:35 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.

Very interesting. We haven't seen a flip to -QBO @ 50mb in the Dec-Jan timeframe since January 1977. That was of course during the great reorganization of the Pacific background state.


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.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#83
wx_statman

Posted 02 November 2017 - 08:07 PM

wx_statman

    Advanced Member

  • Members
  • PipPipPipPipPipPip
  • 4540 posts
  • LocationPortland, OR

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 and Jesse like this

#84
Phil

Posted 02 November 2017 - 10:16 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.

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!
  • wx_statman likes this
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#85
Brian_in_Leavenworth

Posted 06 November 2017 - 12:34 PM

Brian_in_Leavenworth

    Forum Member

  • Members
  • PipPipPip
  • 458 posts

Interesting winter prediction here:  http://m.uploadedit....09722707103.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.

  • Phil, snow_wizard and Front Ranger like this

#86
Front Ranger

Posted 06 November 2017 - 12:55 PM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

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 likes this

Cool anomalies soothe the soul.


#87
Phil

Posted 06 November 2017 - 12:57 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.
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.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#88
Phil

Posted 06 November 2017 - 05:19 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.
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.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#89
Front Ranger

Posted 06 November 2017 - 05:44 PM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

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 likes this

Cool anomalies soothe the soul.


#90
Phil

Posted 06 November 2017 - 06:05 PM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.

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.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#91
Front Ranger

Posted 07 November 2017 - 09:08 AM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

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

 

Attached File  gfs-ens_T850a_namer_54.png   110.9KB   0 downloads


Cool anomalies soothe the soul.


#92
snow_wizard

Posted 07 November 2017 - 07:48 PM

snow_wizard

    The Snow Wizard

  • Mods
  • 13740 posts
  • LocationCovington, WA

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.


Death To Warm Anomalies!

 

Winter 2018-19 stats

 

Total Snowfall = 0.0"

Coldest Low = 35

Lows 32 or below = 0

Highs 32 or below = 0

Lows Below 20 = 0

Highs 40 or below = 0

 

 


#93
snow_wizard

Posted 07 November 2017 - 07:49 PM

snow_wizard

    The Snow Wizard

  • Mods
  • 13740 posts
  • LocationCovington, WA

 

Interesting winter prediction here:  http://m.uploadedit....09722707103.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!


Death To Warm Anomalies!

 

Winter 2018-19 stats

 

Total Snowfall = 0.0"

Coldest Low = 35

Lows 32 or below = 0

Highs 32 or below = 0

Lows Below 20 = 0

Highs 40 or below = 0

 

 


#94
snow_wizard

Posted 07 November 2017 - 10:44 PM

snow_wizard

    The Snow Wizard

  • Mods
  • 13740 posts
  • LocationCovington, WA

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.


Death To Warm Anomalies!

 

Winter 2018-19 stats

 

Total Snowfall = 0.0"

Coldest Low = 35

Lows 32 or below = 0

Highs 32 or below = 0

Lows Below 20 = 0

Highs 40 or below = 0

 

 


#95
Front Ranger

Posted 08 November 2017 - 11:00 AM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

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.


Cool anomalies soothe the soul.


#96
snow_wizard

Posted 10 November 2017 - 12:10 AM

snow_wizard

    The Snow Wizard

  • Mods
  • 13740 posts
  • LocationCovington, WA

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.

 

 

Attached Files


Death To Warm Anomalies!

 

Winter 2018-19 stats

 

Total Snowfall = 0.0"

Coldest Low = 35

Lows 32 or below = 0

Highs 32 or below = 0

Lows Below 20 = 0

Highs 40 or below = 0

 

 


#97
snow_wizard

Posted 10 November 2017 - 12:13 AM

snow_wizard

    The Snow Wizard

  • Mods
  • 13740 posts
  • LocationCovington, WA

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.


Death To Warm Anomalies!

 

Winter 2018-19 stats

 

Total Snowfall = 0.0"

Coldest Low = 35

Lows 32 or below = 0

Highs 32 or below = 0

Lows Below 20 = 0

Highs 40 or below = 0

 

 


#98
ShawniganLake

Posted 10 November 2017 - 07:50 AM

ShawniganLake

    Special Contributor

  • Members
  • PipPipPipPipPipPipPip
  • 5747 posts
  • LocationShawnigan Lake, BC. Southern Vancouver Island, 500ft

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?

#99
Phil

Posted 10 November 2017 - 08:32 AM

Phil

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 21104 posts
  • LocationCabin John, MD.
So far, Flatiron's forecast looks pretty good to me.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...pwsdash#history

#100
Front Ranger

Posted 10 November 2017 - 11:20 AM

Front Ranger

    Forum Fantastic

  • Members
  • PipPipPipPipPipPipPipPip
  • 15229 posts
  • LocationWestminster, CO

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.


  • Phil likes this

Cool anomalies soothe the soul.