Global Average Temperature and the Propagation of Uncertainty

[LibertyBell]

23 hours ago, bdgwx said:

Hansen et al. 1981 was pretty close. If anything they underestimated the warming. From 1979 to 2022 I show 0.8 C of warming based off the linear regression trend of GISTEMP.

about the IPCC predictions, they were a little too conservative, or, put another way, the likely outcome is going to be on the more aggressive side of their predictions....I've noticed the timeline has moved up with each new report.

 

[bluewave]

The climate models did a pretty good job overall when averaged out.

 

 

[George001]

I’m curious to when we can expect New England winters to become snowless due to climate change. There’s growing evidence that the warmth is starting to win out in the mid Atlantic and that’s going to happen farther north as well as climate change continues to accelerate. Its only a matter of time before areas as far north as Boston become nearly snowless at some point during most of our lifetimes. That almost seems like a certainty, the real question is how fast will this happen.

[chubbs]

7 hours ago, George001 said:

I’m curious to when we can expect New England winters to become snowless due to climate change. There’s growing evidence that the warmth is starting to win out in the mid Atlantic and that’s going to happen farther north as well as climate change continues to accelerate. Its only a matter of time before areas as far north as Boston become nearly snowless at some point during most of our lifetimes. That almost seems like a certainty, the real question is how fast will this happen.

My two cents - That depends on us. Feasible to get off fossil fuels in the next three decades, which would end the warming. More foot dragging--> less winter

[Stormchaserchuck1]

On 3/23/2023 at 11:38 PM, George001 said:

I’m curious to when we can expect New England winters to become snowless due to climate change. There’s growing evidence that the warmth is starting to win out in the mid Atlantic and that’s going to happen farther north as well as climate change continues to accelerate. Its only a matter of time before areas as far north as Boston become nearly snowless at some point during most of our lifetimes. That almost seems like a certainty, the real question is how fast will this happen.

I think Dec-Feb 2017-18 Boston getting only 2" of snow, then the headfakes of going into a snowier Winter (Fall 2018 and Fall 2022), not happening, were also accelerants in this direction. 

[raindancewx]

On 3/23/2023 at 9:38 PM, George001 said:

I’m curious to when we can expect New England winters to become snowless due to climate change. There’s growing evidence that the warmth is starting to win out in the mid Atlantic and that’s going to happen farther north as well as climate change continues to accelerate. Its only a matter of time before areas as far north as Boston become nearly snowless at some point during most of our lifetimes. That almost seems like a certainty, the real question is how fast will this happen.

If you look at average snowfall annually/snowfall frequency in North America and plot it against average temperature annually, most of the continent sees sporadic snow up to climates with average temperatures of about ~60-65 degrees. El Paso, Atlanta, Charlotte, Chihuahua, and Norfolk are all examples of places with that level of warmth that see snow in 1/4 to 3/4 of all years still. The rate of warming since the Dustbowl, even if it were to double, implies Boston has 200-300 years before reaching the El Paso / Atlanta / Charlotte / Chihuahua / Norfolk range of 2-10 inch annual snow totals. You'll not live to a see a 10, 20, 30 year period where Boston gets no snow in under 80-90% of the years. 

That said, you're not too far from the next level, 55-60 degrees, which includes Philadelphia, Albuquerque, St. Louis, Amarillo, etc. The 55-60 annual temperature zone tends to see median snowfall in the 5-20 inch range, with infrequent total dud years and infrequent heavy snow years. That's what I'd expect Boston to look like in 100 years, a slightly snowier version of 1991-2020 Philadelphia averages, which means some near 0 duds (1997-98, 2019-20, 2022-23 for Philadelphia), some great years (2014-15, 2013-14, 2009-10), but rarely outside a 10-30 inch range for snowfall.

Locally, we're essentially split into thirds long-term - the dud years are 3 inches or less, the near median years are around 3-13 inches, and the good years are 13+. The difference is, Boston will always have far less sunlight in winter than a place like Philadelphia or Albuquerque in winter, so even if your high low split is 45/25 on January 18, 2125, you'd still have more hours near the 25 than St. Louis would with an identical high/low split. For reference, Albuquerque has an average annual temperature of 58F, Philadelphia is 56F using the current 30 year averages. St. Louis is about 57F, and averages 17 inches of snow. Amarillo is about 59F annually, and averages 18 inches of snow. My guess is Boston will have an average temperature of 55-56 degrees for the 30 years centered on 2120 (up from 52 or 53 from the 30 year period centered on 2020).

 

[LibertyBell]

11 hours ago, raindancewx said:

If you look at average snowfall annually/snowfall frequency in North America and plot it against average temperature annually, most of the continent sees sporadic snow up to climates with average temperatures of about ~60-65 degrees. El Paso, Atlanta, Charlotte, Chihuahua, and Norfolk are all examples of places with that level of warmth that see snow in 1/4 to 3/4 of all years still. The rate of warming since the Dustbowl, even if it were to double, implies Boston has 200-300 years before reaching the El Paso / Atlanta / Charlotte / Chihuahua / Norfolk range of 2-10 inch annual snow totals. You'll not live to a see a 10, 20, 30 year period where Boston gets no snow in under 80-90% of the years. 

That said, you're not too far from the next level, 55-60 degrees, which includes Philadelphia, Albuquerque, St. Louis, Amarillo, etc. The 55-60 annual temperature zone tends to see median snowfall in the 5-20 inch range, with infrequent total dud years and infrequent heavy snow years. That's what I'd expect Boston to look like in 100 years, a slightly snowier version of 1991-2020 Philadelphia averages, which means some near 0 duds (1997-98, 2019-20, 2022-23 for Philadelphia), some great years (2014-15, 2013-14, 2009-10), but rarely outside a 10-30 inch range for snowfall.

Locally, we're essentially split into thirds long-term - the dud years are 3 inches or less, the near median years are around 3-13 inches, and the good years are 13+. The difference is, Boston will always have far less sunlight in winter than a place like Philadelphia or Albuquerque in winter, so even if your high low split is 45/25 on January 18, 2125, you'd still have more hours near the 25 than St. Louis would with an identical high/low split. For reference, Albuquerque has an average annual temperature of 58F, Philadelphia is 56F using the current 30 year averages. St. Louis is about 57F, and averages 17 inches of snow. Amarillo is about 59F annually, and averages 18 inches of snow. My guess is Boston will have an average temperature of 55-56 degrees for the 30 years centered on 2120 (up from 52 or 53 from the 30 year period centered on 2020).

 

I believe NYC will be in that 55-60 zone by 2040 or 2050 at the latest

 

[bluewave]

On 3/23/2023 at 11:38 PM, George001 said:

I’m curious to when we can expect New England winters to become snowless due to climate change. There’s growing evidence that the warmth is starting to win out in the mid Atlantic and that’s going to happen farther north as well as climate change continues to accelerate. Its only a matter of time before areas as far north as Boston become nearly snowless at some point during most of our lifetimes. That almost seems like a certainty, the real question is how fast will this happen.

Future temperatures and snowfall in Boston will come down to which emissions path we follow.

 

 

 

 

 

[bdgwx]

The IPCC's Climate Atlas could be useful tool for assessing questions like these. Unfortunately I find it difficult to use specifically for snowfall though. The Regional Information map itself makes sense, but when I use the "Point information" tool I get a value in mm/day that doesn't make much sense to me and seems to conflict with other information available. We can say that each incremental increase in global warming results in less snowfall for the northeast and other areas of the US for that matter.

[LibertyBell]

4 hours ago, bluewave said:

Future temperatures and snowfall in Boston will come down to which emissions path we follow.

 

 

 

 

 

we need carbon taxes and in a hurry

[LibertyBell]

9 hours ago, bluewave said:

Future temperatures and snowfall in Boston will come down to which emissions path we follow.

 

 

 

 

 

I wonder how quickly we'll get to 2.5 and then 3.0, as the temperatures rise, the rise will accelerate so I see 3.0 occurring before 2100.

 

[Typhoon Tip]

The issue that immediately jumps to mind for me when I hear or read these answers to the question of snow vs CC over eastern N/A ... they appear to assume a linearity, and/or symmetric result and that's philosophically dubious to me.

The forced circulation of the planetary body of atmospheric responses do not typically motivate as a linear 1::1 cause to effect, at all temporal scales and spatial sizes - the latter of course being slower by simple momentum arithmetic and Newtonian dynamics.  and so on

Perhaps a way of backing into that realization?   -  considering "thresholds" (as a verb) phenomenon. These abstract virtual boundaries in how the systems respond to forcing in nature appear to take place once compensating stabilization means, in situ, are finally overcome. An "elasticity" or bounding event or series, resets a location into a new paradigm - in this sense ...we are talking about climate.  There's a reason that scientific circles accept the vernacular, "nearing thresholds..."  etc..

A purely linear/ and symmetric, or coupled causality to observed results, would not suffer threshold phenomenon. A linear atmospheric systemic response, to which climate describes, would move concertedly with the advent of the new forcing. Thresholds, on the other hand, are an acceleration. That's not a straight line in simpler terms.

We cannot logically assume, given that reality, that raising the temperature 1.5C since the Industrial Revolution --> x-y-z, having snow results so far = a-b-c, will continue along that linear projection. It is more likely ...at some point along this journey...  either knowing it is happening, or unwittingly we all just realize, we've ended up on the other side of the virtual boundary (threshold). Some thresholds are crossed silently.

Some would argue that much of eastern SNE is already much more NJ -like, just by anecdotal accounting. Which obviously that is far less than the consilient findings of the scientific ambit.  It's still fun to relate this morass to the common everyday life, though - otherwise why the f are we doing this thing called humanity  ( other than unwittingly forcing a "Fermi boundary event"   )

 

[LibertyBell]

1 hour ago, Typhoon Tip said:

The issue that immediately jumps to mind for me when I hear or read these answers to the question of snow vs CC over eastern N/A ... they appear to assume a linearity, and/or symmetric result and that's philosophically dubious to me.

The forced circulation of the planetary body of atmospheric responses do not typically motivate as a linear 1::1 cause to effect, at all temporal scales and spatial sizes - the latter of course being slower by simple momentum arithmetic and Newtonian dynamics.  and so on

Perhaps a way of backing into that realization?   -  considering "thresholds" (as a verb) phenomenon. These abstract virtual boundaries in how the systems respond to forcing in nature appear to take place once compensating stabilization means, in situ, are finally overcome. An "elasticity" or bounding event or series, resets a location into a new paradigm - in this sense ...we are talking about climate.  There's a reason that scientific circles accept the vernacular, "nearing thresholds..."  etc..

A purely linear/ and symmetric, or coupled causality to observed results, would not suffer threshold phenomenon. A linear atmospheric systemic response, to which climate describes, would move concertedly with the advent of the new forcing. Thresholds, on the other hand, are an acceleration. That's not a straight line in simpler terms.

We cannot logically assume, given that reality, that raising the temperature 1.5C since the Industrial Revolution --> x-y-z, having snow results so far = a-b-c, will continue along that linear projection. It is more likely ...at some point along this journey...  either knowing it is happening, or unwittingly we all just realize, we've ended up on the other side of the virtual boundary (threshold). Some thresholds are crossed silently.

Some would argue that much of eastern SNE is already much more NJ -like, just by anecdotal accounting. Which obviously that is far less than the consilient findings of the scientific ambit.  It's still fun to relate this morass to the common everyday life, though - otherwise why the f are we doing this thing called humanity  ( other than unwittingly forcing a "Fermi boundary event"   )

 

I love these Fermi boundary events....did someone in one of your associations mention this?  I've been talking about this for 30 years as being the real answer to the Fermi Paradox (and I was just talking about this in the NYC subforum winter banter thread)....it's ironic that humanity is about to discover the answer to the Fermi Paradox firsthand!  Such "exciting" times ahead!

 

[bluewave]

4 hours ago, Typhoon Tip said:

The issue that immediately jumps to mind for me when I hear or read these answers to the question of snow vs CC over eastern N/A ... they appear to assume a linearity, and/or symmetric result and that's philosophically dubious to me.

The forced circulation of the planetary body of atmospheric responses do not typically motivate as a linear 1::1 cause to effect, at all temporal scales and spatial sizes - the latter of course being slower by simple momentum arithmetic and Newtonian dynamics.  and so on

Perhaps a way of backing into that realization?   -  considering "thresholds" (as a verb) phenomenon. These abstract virtual boundaries in how the systems respond to forcing in nature appear to take place once compensating stabilization means, in situ, are finally overcome. An "elasticity" or bounding event or series, resets a location into a new paradigm - in this sense ...we are talking about climate.  There's a reason that scientific circles accept the vernacular, "nearing thresholds..."  etc..

A purely linear/ and symmetric, or coupled causality to observed results, would not suffer threshold phenomenon. A linear atmospheric systemic response, to which climate describes, would move concertedly with the advent of the new forcing. Thresholds, on the other hand, are an acceleration. That's not a straight line in simpler terms.

We cannot logically assume, given that reality, that raising the temperature 1.5C since the Industrial Revolution --> x-y-z, having snow results so far = a-b-c, will continue along that linear projection. It is more likely ...at some point along this journey...  either knowing it is happening, or unwittingly we all just realize, we've ended up on the other side of the virtual boundary (threshold). Some thresholds are crossed silently.

Some would argue that much of eastern SNE is already much more NJ -like, just by anecdotal accounting. Which obviously that is far less than the consilient findings of the scientific ambit.  It's still fun to relate this morass to the common everyday life, though - otherwise why the f are we doing this thing called humanity  ( other than unwittingly forcing a "Fermi boundary event"   )

 

Some type of threshold or peak may have been crossed for snowfall at Boston following the 15-16 super El Niño. NYC started to see a decline in snowfall in 18-19. DC also saw less snowfall like Boston following the super El Niño. But we may need another 5-10 years of data in order to confirm since snowfall data can be very noisy. The warming of the winters has become really pronounced with 8 warmer to record warm winters in a row since 15-16. 

 

 Total Snowfall for Boston Area, MA (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Year	Oct	Nov	Dec	Jan	Feb	Mar	Apr	Season
Mean	0.5	0.0	5.3	11.3	11.4	6.8	1.4	36.5
2022-2023	0.0	T	1.0	6.9	3.6	0.9	M	12.4
2021-2022	0.0	T	0.4	36.2	15.3	2.1	T	54.0
2020-2021	4.3	T	13.0	5.8	15.3	0.1	0.1	38.6
2019-2020	0.0	T	11.5	3.1	0.5	T	0.7	15.8
2018-2019	0.0	0.1	0.1	2.1	11.6	13.5	T	27.4
2017-2018	0.0	T	9.2	17.8	8.3	23.3	1.3	59.9
2016-2017	0.0	T	5.9	8.9	21.5	10.1	1.2	47.6
2015-2016	T	0.0	0.9	9.5	15.0	4.1	6.6	36.1

ick column heading to sort ascending, click again to sort descending.

Year	Oct	Nov	Dec	Jan	Feb	Mar	Apr	Season
Mean	0.1	0.4	13.1	18.9	21.2	5.7	0.2	59.5
2014-2015	0.0	2.6	0.3	34.3	64.8	8.6	T	110.6
2013-2014	0.0	T	11.7	21.8	22.9	2.2	0.3	58.9
2012-2013	0.0	0.4	3.4	5.0	34.0	20.6	T	63.4
2011-2012	1.0	T	T	6.8	0.9	0.6	0.0	9.3
2010-2011	0.0	T	22.0	38.3	18.5	1.3	0.9	81.0
2009-2010	0.1	0.0	15.2	13.2	7.0	0.2	0.0	35.7
2008-2009	0.0	T	25.3	23.7	6.2	10.7	0.0	65.9
2007-2008	0.0	T	26.9	8.3	15.0	1.0	0.0	51.2

 

 

 

Monthly Total Snowfall for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Oct	Nov	Dec	Jan	Feb	Mar	Apr	Season
Mean	0.0	1.3	2.6	4.2	6.6	2.2	T	16.8
2022-2023	0.0	0.0	T	T	2.2	0.1	M	2.3
2021-2022	0.0	T	0.2	15.3	2.0	0.4	0.0	17.9
2020-2021	0.0	0.0	10.5	2.1	26.0	T	0.0	38.6
2019-2020	0.0	0.0	2.5	2.3	T	T	T	4.8
2018-2019	0.0	6.4	T	1.1	2.6	10.4	0.0	20.5

 

 

 

 

Monthly Total Snowfall for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

Year	Oct	Nov	Dec	Jan	Feb	Mar	Apr	Season
Mean	0.0	0.0	4.1	16.7	12.2	8.2	1.1	42.3
2017-2018	0.0	T	7.7	11.2	4.9	11.6	5.5	40.9
2016-2017	0.0	T	3.2	7.9	9.4	9.7	0.0	30.2
2015-2016	0.0	0.0	T	27.9	4.0	0.9	T	32.8
2014-2015	0.0	0.2	1.0	16.9	13.6	18.6	0.0	50.3
2013-2014	0.0	T	8.6	19.7	29.0	0.1	T	57.4

 

Monthly Total Snowfall for Washington Area, DC (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Year	Oct	Nov	Dec	Jan	Feb	Mar	Apr	Season
Mean	0.0	0.2	0.3	6.0	1.3	1.0	T	8.7
2022-2023	0.0	0.0	T	T	0.4	T	M	0.4
2021-2022	0.0	0.0	0.0	12.3	T	0.9	0.0	13.2
2020-2021	0.0	0.0	T	2.6	2.8	0.0	0.0	5.4
2019-2020	0.0	0.0	0.4	0.2	T	0.0	0.0	0.6
2018-2019	0.0	1.4	0.0	11.5	3.7	0.3	0.0	16.9
2017-2018	0.0	0.0	1.9	1.2	0.2	4.5	T	7.8
2016-2017	0.0	0.0	T	1.4	T	2.0	0.0	3.4
2015-2016	0.0	0.0	0.0	18.8	3.1	0.3	T	22.2

 

Monthly Total Snowfall for Washington Area, DC (ThreadEx)
Click column heading to sort ascending, click again to sort descending.

Year	Oct	Nov	Dec	Jan	Feb	Mar	Apr	Season
Mean	T	T	2.9	3.8	6.9	3.1	T	16.8
2014-2015	0.0	T	T	3.6	9.8	4.9	T	18.3
2013-2014	0.0	T	1.5	6.6	11.2	12.7	T	32.0
2012-2013	0.0	T	0.2	0.9	0.4	1.6	0.0	3.1
2011-2012	T	0.0	T	1.7	0.3	T	0.0	2.0
2010-2011	0.0	T	2.1	7.3	0.5	0.2	T	10.1
2009-2010	0.0	0.0	16.6	7.4	32.1	T	0.0	56.1
2008-2009	0.0	T	T	1.9	0.1	5.5	0.0	7.5
2007-2008	0.0	0.0	2.6	1.3	1.0	0.0	0.0	4.9

 

A record breaking 8 warmer than normal winters in a row since the 15-16 super El Niño in NYC.
 

NYC

Feb 23…+5.2

Jan 23…+9.8

Dec 22…-0.6

…………..+4.8

 

Feb 22….+1.4

Jan 22….-3.2

Dec 21….+4.7

……………..+1.0

 

Feb 21….-1.7

Jan 21….+1.1

Dec 20…+1.7

…………..+0.4

 

Feb 20…+4.8

Jan 20….+6.5

Dec 19….+0.8

…………….+4.0

 

Feb 19….+0.9

Jan 19….-0.1

Dec 18…+2.6

…………….+1.1

 

Feb 18…+6.7

Jan 18….-0.9

Dec 17…..-2.5

…………….+1.1

 

Feb 17…..+6.3

Jan 17….+5.4

Dec 16….+0.8

…………….+4.2

 

Feb 16….+2.4

Jan 16….+1.9

Dec 15….+13.3

……………..+5.9

[ORH_wxman]

You'll need a lot longer than 10 more years to figure out snowfall climo.

BOS average of nearly 60 inches between 2007-2015 is a ridiculous baseline to measure against as it is. The 36.5" mean since 2015-16 is a lot closer to their longterm snowfall climo than the 59.5" mean from 2007-2015.

 

BOS moving 20 year average...even that doesn't tell you much on the 20 year level.

[bluewave]

53 minutes ago, ORH_wxman said:

You'll need a lot longer than 10 more years to figure out snowfall climo.

BOS average of nearly 60 inches between 2007-2015 is a ridiculous baseline to measure against as it is. The 36.5" mean since 2015-16 is a lot closer to their longterm snowfall climo than the 59.5" mean from 2007-2015.

We were trying to figure out when or if a snowfall threshold has been passed due to warming. But like I said, it will  take much more data to determine. The 2007-2015 period is interesting in that it represents a peak in snowfall for our modern era at a place like Boston. If we can’t realize another peak like this in the coming decades, then the warming following the super El Niño may turn out to be threshold when the decline began. But the warming has been undeniable. The trick is at what point does the warming lead to reduced snowfall? Determining longer term climo is challenging for snowfall since measurement methods have changed over the years. Many older snowfall seasons would be higher with the more frequent measurement standards of modern times. So the slight rise at Boston could become closer to even or show a slight decline with corrected higher measurements in the earlier era.

 

https://news.ucar.edu/14009/snowfall-measurement-flaky-history

Earlier in our weather history, the standard practice was to record snowfall amounts less frequently, such as every 12 or 24 hours, or even to take just one measurement of depth on the ground at the end of the storm.

You might think that one or two measurements per day should add up to pretty much the same as measurements taken every 6 hours during the storm. It’s a logical assumption, but you would be mistaken. Snow on the ground gets compacted as additional snow falls. Therefore, multiple measurements during a storm typically result in a higher total than if snowfall is derived from just one or two measurements per day.

That can make quite a significant difference. It turns out that it’s not uncommon for the snow on the ground at the end of a storm to be 15 to 20 percent less than the total that would be derived from multiple snowboard measurements.  As the cooperative climate observer for Boulder, Colorado, I examined the 15 biggest snowfalls of the last two decades, all measured at the NOAA campus in Boulder. The sum of the snowboard measurements averaged 17 percent greater than the maximum depth on the ground at the end of the storm. For a 20-inch snowfall, that would be a boost of 3.4 inches—enough to dethrone many close rivals on the top-10 snowstorm list that were not necessarily lesser storms!

Another common practice at the cooperative observing stations prior to 1950 did not involve measuring snow at all, but instead took the liquid derived from the snow and applied a 10:1 ratio (every inch of liquid equals ten inches of snow). This is no longer the official practice and has become increasingly less common since 1950. But it too introduces a potential low bias in historic snowfalls because in most parts of the country (and in the recent blizzard in the Northeast) one inch of liquid produces more than 10 inches of snow.

This means that many of the storms from the 1980s or earlier would probably appear in the record as bigger storms if the observers had used the currently accepted methodology. Now, for those of you northeasterners with aching backs from shoveling, I am not saying that your recent storm wasn’t big in places like Boston, Portland, or Long Island. But I am saying that some of the past greats—the February Blizzard of 1978, the Knickerbocker storm of January 1922, and the great Blizzard of March 1888—are probably underestimated.

So keep in mind when viewing those lists of snowy greats: the older ones are not directly comparable with those in recent decades. It’s not as bad as comparing apples to oranges, but it may be like comparing apples to crabapples.

Going forward, we can look for increasingly accurate snow totals. Researchers at NCAR and other organizations are studying new approaches for measuring snow more accurately (see related story: Snowfall, inch by inch).  

But we can’t apply those techniques to the past. For now, all we can say is that snowfall measurements taken more than about 20 or 30 years ago may be unsuitable for detecting trends – and perhaps snowfall records from the past should not be melting away quite as quickly as it appears.

Update • January 29, 2015 | Thanks to thoughtful feedback by several colleagues, this article has been updated. Paragraph 3 now includes a description of how climate studies handle the data inconsistencies. Paragraph 9 was added to describe the pre-1950s practice, no longer in wide use, of recording liquid water content only, and not snow depth.

 

 

 

[ORH_wxman]

How do you know the 2007-2015 peak was due to warming and not other factors? 
 

That’s the whole problem with the exercise. When you use such short periods to try and figure out if warming caused some sort of a tend, you inherently introduce massive natural variability into the equation. 

[bluewave]

14 minutes ago, ORH_wxman said:

How do you know the 2007-2015 peak was due to warming and not other factors? 
 

That’s the whole problem with the exercise. When you use such short periods to try and figure out if warming caused some sort of a tend, you inherently introduce massive natural variability into the equation. 

I didn’t specifically address the reason for the 2007-2015 peak in snowfall at Boston. But you raise an interesting question. There have been several papers focusing on the long term warming in the WPAC in regard to the record snowfall at Boston that year. The Rossby wave train from WPAC lead to the record blocking in the EPO an PNA regions which set the table for what happened that winter.

[ORH_wxman]

10 minutes ago, bluewave said:

I didn’t specifically address the reason for the 2007-2015 peak in snowfall at Boston. But you raise an interesting question. There have been several papers focusing on the long term warming in the WPAC in regard to the record snowfall at Boston that year. The Rossby wave train from WPAC lead to the record blocking in the EPO an PNA regions which set the table for what happened that winter.

But you’re going to use the 2007-2015 period as baseline to try and pick out when an “inflection” happened (supposedly 2015 in your original hypothesis) due to warming and then using future 8 year chunks to measure against it….I originally objected due to how short such a period is. We could’ve done the same exercise in the 1960s/1970s and then determined 2 decades later that we reached an “inflection point” because we couldn’t match the snowiest 8 year period from then…and we would have been wrong…because 8 years is obscenely short to try and figure out climate trends. 
 

I don’t think you can use rolling 8 year chunks to figure it out. You need something way longer. 

[ORH_wxman]

I think if you theoretically ran it out like 50-100 years you could maybe do 8 year chunks to try and compare….but at that point, you might as well just use rolling 30 year normals. 

[bluewave]

2 hours ago, ORH_wxman said:

But you’re going to use the 2007-2015 period as baseline to try and pick out when an “inflection” happened (supposedly 2015 in your original hypothesis) due to warming and then using future 8 year chunks to measure against it….I originally objected due to how short such a period is. We could’ve done the same exercise in the 1960s/1970s and then determined 2 decades later that we reached an “inflection point” because we couldn’t match the snowiest 8 year period from then…and we would have been wrong…because 8 years is obscenely short to try and figure out climate trends. 
 

I don’t think you can use rolling 8 year chunks to figure it out. You need something way longer. 

I was more asking a question rather than making a definitive statement in regard to snowfall. That’s why I mentioned that we will need more data to make a determination. We know with pretty high degree of certainty that the range between higher and lower snowfall seasons has been increasing since the 90s. Many high and low extremes rather than seasons falling more toward the middle of the distribution. So the increasing range may be indicative of a change in the system before warming skews toward the probability extreme lows becoming more common than extreme highs like in 14-15. Conditions are much warmer now than the 1960s and 1970s. So we are much closer now to the possibilities of approaching diminishing snowfall outcomes as is expected with climate change. The only question is what the exact timing will be. 

[LibertyBell]

2 hours ago, ORH_wxman said:

You'll need a lot longer than 10 more years to figure out snowfall climo.

BOS average of nearly 60 inches between 2007-2015 is a ridiculous baseline to measure against as it is. The 36.5" mean since 2015-16 is a lot closer to their longterm snowfall climo than the 59.5" mean from 2007-2015.

 

BOS moving 20 year average...even that doesn't tell you much on the 20 year level.

I was shocked it went that high, Will.  I always figured that Boston's snowfall climo mean should be around 42"

50" is Minneapolis territory and Boston definitely isn't as snowy as Minneapolis is.

 

[Typhoon Tip]

Not sure I see very much disagreement between y'all - in so far as where it counts...  You're both suggesting you need more data, specifically ... as it pertains to validating whether or not declination of snow totaling is now (or not) a dependable delta in Boston's climate.

First of all, I wouldn't use Logan as a proxy in that.  Too much oceanic interference - or in the least, the proximity to the ocean would need to be ruled out somehow geo-physically/statistically as a contaminated data series.  

Probably, use the triangular method: HFD-CON-ALB.  Then perhaps do a separate region that is bounded by BED-PVD-ORH.  Reanalysis techniques may also speed some of that up... however, I would aver at this time that if anything, the snow should be increasing, until such time as a "threshold" is breached.   It's unclear that 8 years of anything in climate means very much.  If we go by that scale, the 1970s would have us staring up the fascia of a 1/2 mi high ice sheet by now - kidding... 

That all said, the threshold idea ( which IS veracious, unfortunately) means that it may not take 50-100 years.  It may not take 20 years for that matter.... or 10 or 5... That's the point. Particularly if it's a silent boundary, like going through an Event Horizon - you may not noticing anything particularly out of the ordinary going over a threshold.  Again... you just sort of wake up one day and realize you're not going back.

What has me a little spooked is that the climate modeling is already behind the rapidity of noted changes, so theoretical thresholds are closer than thought would be as recent as the projections from 20 years ago.   See...  don't look at the 1.5C since the Industrial Revolution.  Decimals in that average are not linearly, or symmetrically distributed across the face of the planet, nor is the affect of CC. 

[LibertyBell]

2 hours ago, ORH_wxman said:

You'll need a lot longer than 10 more years to figure out snowfall climo.

BOS average of nearly 60 inches between 2007-2015 is a ridiculous baseline to measure against as it is. The 36.5" mean since 2015-16 is a lot closer to their longterm snowfall climo than the 59.5" mean from 2007-2015.

 

BOS moving 20 year average...even that doesn't tell you much on the 20 year level.

all you have to do is look at the 80s to see how 10 years isn't enough for snowfall.....30 years may not even be enough.  I would go with 60 year averages honestly.

 

[LibertyBell]

2 minutes ago, Typhoon Tip said:

Not sure I see very much disagreement between y'all - in so far as where it counts...  You're both suggesting you need more data, specifically ... as it pertains to validating declination of snow totaling is now a dependable delta in Boston's climate.

First of all, I wouldn't use Logan as a proxy in that.  Too much oceanic interference - or in the least, the proximity to the ocean would need to be ruled out somehow geo-physically/statistically as a contaminated data series.  

Probably, use the triangular method: HFD-CON-ALB.  Then perhaps do a separate region that is perhaps BED-PVD-ORH.  Reanalysis techniques may also speed some of that up... however, I would aver at this time that if anything, the snow should be increasing, until such time as a "threshold" is breached.   It's unclear that 8 years of anything in climate means very much.  If we go by that scale, the 1970s would have us staring up the fascia of a 1/2 high ice sheet by - kidding... 

That all said, the threshold idea ( which IS veracious, unfortunately) means that it may not take 50-100 years.  It may not take 20 years for that matter.... or 10 or 5... That's the point. Particularly if the if it's a silent boundary, like going through an Event Horizon - you may not noticing anything particularly out of the ordinary going over a threshold.  Again... you just sort of wake up one day and realize you're on going back.

What has me a little spooked is that the climate modeling is already behind the rapidity of noted changes, so theoretical thresholds are closer than thought would be as recent as the projections from 20 years ago.   See...  don't look at the 1.5C since the Industrial Revolution.  Decimals in that average are not linearly, or symmetrically distributed across the face of the planet, nor is the affect of CC. 

whats fascinating that inside a supermassive black hole you wouldn't even get crushed, it really is more like entering  a new universe....sure you can't go back but you wouldn't even realize that.

 

[Typhoon Tip]

2 hours ago, ORH_wxman said:

You'll need a lot longer than 10 more years to figure out snowfall climo.

BOS average of nearly 60 inches between 2007-2015 is a ridiculous baseline to measure against as it is. The 36.5" mean since 2015-16 is a lot closer to their longterm snowfall climo than the 59.5" mean from 2007-2015.

 

BOS moving 20 year average...even that doesn't tell you much on the 20 year level.

LOL ... proof that the 1980s blew pickle dicks

[LibertyBell]

Just now, Typhoon Tip said:

LOL ... proof that the 1980s blew pickle dicks

it was really cold though lol

 

[ORH_wxman]

3 minutes ago, Typhoon Tip said:

LOL ... proof that the 1980s blew pickle dicks

Yeah that is a brutal dip even in the 20 year average. 

[ORH_wxman]

Another factor the complicates these types of questions of projecting future snowfall trends is regional temperature variability. Like if we did an analysis on the warming from, say, 1970-2000, we would’ve seen a bullseye of warming over the northern plains with a cooling trend in SE Canada…you do the same analysis from 1995ish until now, you get a cooling trend in the same northern plains spot while SE Canada has the highest warming (and within the US border the highest warming is the northeast in that time frame). 
 

 

[bdgwx]

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