Winter 2020-2021

[raindancewx]

I hope you understand how severe 1970-71 is in small doses if you use it as an analog - lots of very fast changes in airmasses. The January high in Albuquerque wasn't even below average here despite the severity of this week, which saw multiple lows below -10F:

I do think the rapid/severe change in airmasses is part of the pattern for the next few months in at least the Rockies. We're going to see 80s to snow this month after 90s to snow last month in NM & CO.

 

 

 

[uncle W]

37 minutes ago, raindancewx said:

I hope you understand how severe 1970-71 is in small doses if you use it as an analog - lots of very fast changes in airmasses. The January high in Albuquerque wasn't even below average here despite the severity of this week, which saw multiple lows below -10F:

I do think the rapid/severe change in airmasses is part of the pattern for the next few months in at least the Rockies. We're going to see 80s to snow this month after 90s to snow last month in NM & CO.

 

 

 

meh...the 6" of snow that fell New Years day 1971 was washed away by a rain storm a few days later...January 1971 was cold in NYC...February was milder and storms were just warm enough for rain on the coast...heavy snows inland...

[sebastiaan1973]

Thanks Benchmark. Intresting read.

In your blog, you speak about a mixed La Nina

http://easternmassweather.blogspot.com/2020/10/mixed-signals-regarding-enso-for-winter.html in

1970-1971

1999-2000

2007-2008

All of these years had a SSW. 

[michsnowfreak]

11 hours ago, raindancewx said:

I hope you understand how severe 1970-71 is in small doses if you use it as an analog - lots of very fast changes in airmasses. The January high in Albuquerque wasn't even below average here despite the severity of this week, which saw multiple lows below -10F:

I do think the rapid/severe change in airmasses is part of the pattern for the next few months in at least the Rockies. We're going to see 80s to snow this month after 90s to snow last month in NM & CO.

 

 

 

isn't la nina in general known for its wild swings? That's what I always thought. 

[40/70 Benchmark]

13 hours ago, raindancewx said:

I hope you understand how severe 1970-71 is in small doses if you use it as an analog - lots of very fast changes in airmasses. The January high in Albuquerque wasn't even below average here despite the severity of this week, which saw multiple lows below -10F:

I do think the rapid/severe change in airmasses is part of the pattern for the next few months in at least the Rockies. We're going to see 80s to snow this month after 90s to snow last month in NM & CO.

 

 

 

One of the best analogs IMO.....volatility should be a central theme this season.

[40/70 Benchmark]

2 hours ago, sebastiaan1973 said:

Thanks Benchmark. Intresting read.

In your blog, you speak about a mixed La Nina

http://easternmassweather.blogspot.com/2020/10/mixed-signals-regarding-enso-for-winter.html in

1970-1971

1999-2000

2007-2008

All of these years had a SSW. 

Interesting-

I would say 1999-2000 is the best QBO match of the 3....1970 and 2007 were very negative QBO.

[CoastalWx]

2 hours ago, michsnowfreak said:

isn't la nina in general known for its wild swings? That's what I always thought. 

Yes. Unless you have the Bering Sea to Gulf of AK trough to blowtorch the US, you'll get volatility with the propensity for very cold airmasses to enter the central US.

[ORH_wxman]

4 minutes ago, 40/70 Benchmark said:

One of the best analogs IMO.....volatility should be a central theme this season.

'70-'71 was absolutely frigid in New England despite the volatility out west. I don't have the exact figures in front of me but ORH went something like this for departures for DJFM.....-7, -6, -1, -5.

I think the main reason for that was that winter had a predominately negative NAO with a poleward Aleutian ridge edged toward the WPO side....it's a very cold pattern for Canada, and then throw in a -NAO, it's a very exceptional pattern for New England. It quickly transitioned into above average temps int he southeast US. 

[CoastalWx]

3 minutes ago, ORH_wxman said:

'70-'71 was absolutely frigid in New England despite the volatility out west. I don't have the exact figures in front of me but ORH went something like this for departures for DJFM.....-7, -6, -1, -5.

I think the main reason for that was that winter had a predominately negative NAO with a poleward Aleutian ridge edged toward the WPO side....it's a very cold pattern for Canada, and then throw in a -NAO, it's a very exceptional pattern for New England. It quickly transitioned into above average temps int he southeast US. 

I looked up Jan '71 for here. That was a frigid AND dry month. The lack of moisture basically was the reason for not having a blockbuster month. Go figure. 

[ORH_wxman]

I just pulled this up....you can see the two cores of cold...one in the typical area of the upper plains, but then a secondary cold max over New England....it was due to the NAO that winter. Prob lots of would-be cutters getting rejected and getting squashed south of New England as redevelopers, so west of the Apps gets warm-sectored on some of those while it never happens over this way...and that winter was super active for storms, so this happened a lot.

 

[40/70 Benchmark]

7 minutes ago, ORH_wxman said:

'70-'71 was absolutely frigid in New England despite the volatility out west. I don't have the exact figures in front of me but ORH went something like this for departures for DJFM.....-7, -6, -1, -5.

I think the main reason for that was that winter had a predominately negative NAO with a poleward Aleutian ridge edged toward the WPO side....it's a very cold pattern for Canada, and then throw in a -NAO, it's a very exceptional pattern for New England. It quickly transitioned into above average temps int he southeast US. 

Its important to note that although I do value it as an analog, I do not expect the entirety of the season to transpire exactly like that. I know that you know this. I will explain how that season will be representative of the overall pattern and when.

[CoastalWx]

Feb was -1.5, but fairly wet with BN snow. Definitely a frustrating Jan-Feb IMO if that were to happen.

[ORH_wxman]

1 minute ago, CoastalWx said:

I looked up Jan '71 for here. That was a frigid AND dry month. The lack of moisture basically was the reason for not having a blockbuster month. Go figure. 

The New Years Day '71 system actually got squashed too far south for us....it was NYC's only good storm that winter. I think parts of CT got warning snows, but up in our area it was like 3-5".

[CoastalWx]

2 minutes ago, ORH_wxman said:

The New Years Day '71 system actually got squashed too far south for us....it was NYC's only good storm that winter. I think parts of CT got warning snows, but up in our area it was like 3-5".

Looks like we got about 6" here. We had snow OTG all month, but too bad we couldn't grab a few more storms. 2nd biggest storm that month was 3.4". 

[ORH_wxman]

1 minute ago, CoastalWx said:

Feb was -1.5, but fairly wet with BN snow. Definitely a frustrating Jan-Feb IMO if that were to happen.

That month had two big ice storms in the interior....a snow to ice scenario. Prob sucked for the coast. I think ORH was near normal snow in Feb '71 but had a ton of ice. I think it was the 2/7 or 2/8/71 that had the big one. Not quite on the level of Dec '08 or Dec '64 in ORH but pretty big ice storm. A lot of sleet saved it from being in the class with those others.

[ORH_wxman]

3 minutes ago, CoastalWx said:

Looks like we got about 6" here. We had snow OTG all month, but too bad we couldn't grab a few more storms. 2nd biggest storm that month was 3.4". 

We were prob a little unlucky in Jan '71 but it made up for being lucky in Dec '70.

Either way, it was a very solid winter....esp over the interior. The coast had some frustrating periods, esp in Feb '71...and I think there was another snow to ice event in early March too that prob sucked for the coast. It was an epic winter for CNE/NNE though....even just north of ORH had like 30" more snow...and ORH already had 80" that winter. I think the Ashburnham coop had like 105-110" or something.

[CoastalWx]

1 minute ago, ORH_wxman said:

We were prob a little unlucky in Jan '71 but it made up for being lucky in Dec '70.

Either way, it was a very solid winter....esp over the interior. The coast had some frustrating periods, esp in Feb '71...and I think there was another snow to ice event in early March too that prob sucked for the coast. It was an epic winter for CNE/NNE though....even just north of ORH had like 30" more snow...and ORH already had 80" that winter. I think the Ashburnham coop had like 105-110" or something.

December would have made the grade a lot better. 2nd best locally and just a few tenths of an inch below '08 here.  I'll take that anytime. Not too often you have a foot of snow OTG for Christmas around here like you did in 1970.

[ORH_wxman]

12 minutes ago, CoastalWx said:

December would have made the grade a lot better. 2nd best locally and just a few tenths of an inch below '08 here.  I'll take that anytime. Not too often you have a foot of snow OTG for Christmas around here like you did in 1970.

Yeah double digit snow pack on Xmas is rare on the coast...it's not super common here over the interior either though it happens a little more frequently. For the coast, off the top of my head, my guess would be maybe:

1995, 1975, 1970, 1961, 1945?, any earlier is knickers of yore territory and I don't have good knowledge embedded in me on those years....maybe i missed one or two in the late 20th century

For a place like ORH, maybe you add on 2007, 2002 (if you count later in the afternoon...only was a couple inches at 7am), and perhaps 1966. Maybe 1960, though that storm had prob settled to below 10" by Xmas.

[ORH_wxman]

Xmas 2017 was close, but no cigar...it was like 5" on top of 2-3" of glacier.

[RUNNAWAYICEBERG]

Cold/dry then warm/wet. Like the 80s baby. 

[CoastalWx]

7 minutes ago, ORH_wxman said:

Yeah double digit snow pack on Xmas is rare on the coast...it's not super common here over the interior either though it happens a little more frequently. For the coast, off the top of my head, my guess would be maybe:

1995, 1975, 1970, 1961, 1945?, any earlier is knickers of yore territory and I don't have good knowledge embedded in me on those years....maybe i missed one or two in the late 20th century

For a place like ORH, maybe you add on 2007, 2002 (if you count later in the afternoon...only was a couple inches at 7am), and perhaps 1966. Maybe 1960, though that storm had prob settled to below 10" by Xmas.

Yeah I think I had around a foot on Christmas, '95.  Christmas '08 and '09 had a good pack, but Christmas '08 started to torch. I think in '09, best pack was down in SE MA because of the big storm earlier.

[ORH_wxman]

2 minutes ago, CoastalWx said:

Yeah I think I had around a foot on Christmas, '95.  Christmas '08 and '09 had a good pack, but Christmas '08 started to torch. I think in '09, best pack was down in SE MA because of the big storm earlier.

Totally forgot '09....yeah up here we actually had less than the southeast areas on Xmas morning. Prob like 8" or so. SE areas had over a foot probably. Yeah '08 was torched on the coast....I had to pick up my sister in Boston that morning, and drove into bare ground (with patches) while it was still like 7-8" of glacier in ORH. '07 actually survived a bit better on the coast I think.

[CoastalWx]

5 minutes ago, ORH_wxman said:

Totally forgot '09....yeah up here we actually had less than the southeast areas on Xmas morning. Prob like 8" or so. SE areas had over a foot probably. Yeah '08 was torched on the coast....I had to pick up my sister in Boston that morning, and drove into bare ground (with patches) while it was still like 7-8" of glacier in ORH. '07 actually survived a bit better on the coast I think.

07 was bare IIRC. We lost it.

 

Edit, we had a bit of a glacier. Was deep until the Grinch came.

[backedgeapproaching]

31 minutes ago, ORH_wxman said:

We were prob a little unlucky in Jan '71 but it made up for being lucky in Dec '70.

Either way, it was a very solid winter....esp over the interior. The coast had some frustrating periods, esp in Feb '71...and I think there was another snow to ice event in early March too that prob sucked for the coast. It was an epic winter for CNE/NNE though....even just north of ORH had like 30" more snow...and ORH already had 80" that winter. I think the Ashburnham coop had like 105-110" or something.

Was just looking at the COOP data locally in SVT and most locations peaked at 40-60" depth in March, so definitely looked like a solid winter without even looking at snow totals. Even bottom of the valley here which torches was 36" peak.

[michsnowfreak]

57 minutes ago, CoastalWx said:

Yes. Unless you have the Bering Sea to Gulf of AK trough to blowtorch the US, you'll get volatility with the propensity for very cold airmasses to enter the central US.

Makes sense. Not all, but most la nina winters feature above avg snowfall and precip here with lots of storniness, but usually not any amazing snowpack because of the thaws/torches thrown in there. 2007-08 was famous for that. in a week you could have 3 snowstorms, a low below zero and a high in the 50s. An even more extreme example was 1949-50, though this one had more emphasis on the warm spells than 2007-08.

[ORH_wxman]

2 minutes ago, michsnowfreak said:

Makes sense. Not all, but most la nina winters feature above avg snowfall and precip here with lots of storniness, but usually not any amazing snowpack because of the thaws/torches thrown in there. 2007-08 was famous for that. in a week you could have 3 snowstorms, a low below zero and a high in the 50s. An even more extreme example was 1949-50, though this one had more emphasis on the warm spells than 2007-08.

What about 2010-2011 there? That must have had pretty deep pack.

[Snowstorms]

1 hour ago, ORH_wxman said:

'70-'71 was absolutely frigid in New England despite the volatility out west. I don't have the exact figures in front of me but ORH went something like this for departures for DJFM.....-7, -6, -1, -5.

I think the main reason for that was that winter had a predominately negative NAO with a poleward Aleutian ridge edged toward the WPO side....it's a very cold pattern for Canada, and then throw in a -NAO, it's a very exceptional pattern for New England. It quickly transitioned into above average temps int he southeast US. 

1970-71 was Canada's coldest winter ever. The entire country was below normal. Monthly departures here in Toronto were about the same as ORH. We got 30" in Dec 1970. Wouldn't the massive warm pool in the Central Pacific influence or increase the chances for a more poleward Aleutian ridge? 

[michsnowfreak]

37 minutes ago, ORH_wxman said:

What about 2010-2011 there? That must have had pretty deep pack.

2010-11 was a cold, snowy winter but still had a few thaws. if not for a brief torch on new years and in mid feb we would have had a great pack.  After a nice white Christmas season, a torch on New Year's Eve zapped the 6" pack away. Snow cover returned a few days later and we nickeled and dimed all through January. much of Januarys snowpack ranged from 3-7" (all powder so settling/compacting)  The early February snowpack got up to about 16 to 18" before a mid February torch melted it.  This torch was a little worse than the New Year's Eve torch naturally because there was more snow to melt. The last of the snow outside of piles and drifts melted on the 19th then on the 20th we got a 10" snowstorm. The entire winter was all powder until a few clingy March storms. The winter ended around 70" with well below average temps but those few damn torches were the black marks. very few days of bare ground that winter but the 2 torches prevented a 2013-14esque pack.

 

[weathafella]

You can already see the tendency in the ensembles to push the poleward Aleutian ridge.   The only question is whether it holds and also whether it migrates East or west.   

[40/70 Benchmark]

12 minutes ago, weathafella said:

You can already see the tendency in the ensembles to push the poleward Aleutian ridge.   The only question is whether it holds and also whether it migrates East or west.   

I do think it sets up, but will not persist all season.