Jump to content
  • Member Statistics

    17,502
    Total Members
    7,904
    Most Online
    Weathernoob335
    Newest Member
    Weathernoob335
    Joined

January 2023


wdrag
 Share

Recommended Posts

32 minutes ago, bluewave said:

The other possibility is that the record breaking SE Ridge since 2015 is being forced by climate change. So it could turn out to be a new climate change teleconnection. Record Gulf Stream warmth combined with record MJO 4-6 warm pool in the WPAC.

6A748CEF-5FCD-4DA5-B1CA-7E6644376A9B.png.9dff3572f35354a8d0fc18ef08750346.png


F6D804C6-22FD-4B62-9E7E-02E864144B07.png.25f702b4c6401a16fc914dcc425651c6.png

 

I think it's everything together. I think that Pacific warm pool is a big deal though. I fear that thing. I strongly believe it's playing a role with that as it likes to drive a -PNA typically. So that's a logical response to that. But I also think la nina is amplifying that response to an extent since then. Because we seem to be in a la nina like cycle since then as well. By increasing the gradient next to that warm pool. Amplifying it's effectiveness. We did have the weak el nino in 18-19. However the gradient was non existent to the west of that because of that warm pool. So I think this is why that one acted atypical and more enso neutral like. No contrast. Same sort of situation for 19-20. This makes me very skeptical of the next el nino as well though. We'll need to see some gradients. Otherwise I think it's going to be useless again. 

20230127_134801.thumb.jpg.51e338166c7cf5bef08a0f7ac2151330.jpg

  • Like 3
Link to comment
Share on other sites

1 hour ago, rclab said:

Good afternoon Don. You sparked a memory from the late 50’s. I remember a newsman in DC reporting on a congressional bill and saying that it would have to be passed by the time the first snow flys on November 15th. Stay well as always ….

That really is something.  Now we almost never get freezes before Nov 15th...

  • Like 3
Link to comment
Share on other sites

16 minutes ago, EasternLI said:

I think it's everything together. I think that Pacific warm pool is a big deal though. I fear that thing. I strongly believe it's playing a role with that as it likes to drive a -PNA typically. So that's a logical response to that. But I also think la nina is amplifying that response to an extent since then. Because we seem to be in a la nina like cycle since then as well. By increasing the gradient next to that warm pool. Amplifying it's effectiveness. We did have the weak el nino in 18-19. However the gradient was non existent to the west of that because of that warm pool. So I think this is why that one acted atypical and more enso neutral like. No contrast. Same sort of situation for 19-20. This makes me very skeptical of the next el nino as well though. We'll need to see some gradients. Otherwise I think it's going to be useless again. 

20230127_134801.thumb.jpg.51e338166c7cf5bef08a0f7ac2151330.jpg

Yeah, the warming Gulf Stream and Western Pacific  are probably our two most important climate influences since 2015-2016. They both reinforce a more La Niña-like pattern. So we get the dominant  SE Ridge pattern. 

 

 

 

 

  • Like 2
  • Thanks 2
Link to comment
Share on other sites

3 minutes ago, bluewave said:

Yeah, the warming Gulf Stream and Western Pacific  are probably our two most important climate influences since 2015-2016. They both reinforce a more La Niña-like pattern. So we get the perma SE Ridge pattern. 

 

 

 

 

Couldn’t the slowing AMOC eventually override this warming signal by the overall reduced volume of warm water transported poleward? Granted, this is likely not an “in our lifetimes” kind of thing, merely something I’m curious about. 

Link to comment
Share on other sites

2 hours ago, donsutherland1 said:

In New York City, winters are warming, the measurable snow season is shrinking in length, and the average number of events is falling. However, the benefits of added moisture (warm air holds more moisture) has contributed to rising seasonal snowfall as the average event is now larger. There will come a time when the warming is sufficiently great to offset the benefits of added moisture. That process is underway in Washington, DC, but not Philadelphia or New York. It could be another decade or two before such a trend develops in Philadelphia and New York City (an additional 1.0°-1.5° of winter warming is likely needed if Washington's data is representative).

As we move toward that inflection point, one will probably see greater variability between high snow and very low snowfall winters, the latter will often be exceptionally warm even against the 1991-2020 reference period.

Good to hear that you believe that it could be quite awhile before our average snowfall starts going down. Thanks as always for your insight, Don. Your posts are great. 

Link to comment
Share on other sites

1 minute ago, Volcanic Winter said:

Couldn’t the slowing AMOC eventually override this warming signal by the overall reduced volume of warm water transported poleward? Granted, this is likely not an “in our lifetimes” kind of thing, merely something I’m curious about. 

The slowing AMOC is enhancing the warming pattern. It allows the warm waters to pile up along the East Coast. The only part of the globe that is cooling from this is localized area south of Greenland. 
 

 

  • Like 2
  • Thanks 2
Link to comment
Share on other sites

3 minutes ago, winterwx21 said:

Good to hear that you believe that it could be quite awhile before our average snowfall starts going down. Thanks as always for your insight, Don. Your posts are great. 

Thanks Winterwx21.

The variability between snowy winters and those with a noted lack of snowfall could increase as we move through the transition.

Perhaps there is already somewhat of a signal starting to appear when it comes to measurable snowfall droughts. 6 of the 11 (55%) stretches of 300 or more days without measurable snow have occurred since 2000. If one throws in 1997-98, 7 of the 11 (64%) have occurred since 1990. If one expands the pool to cases of 290 days or more, 9/21 (43%) of such streaks have occurred since 2000 while 10/21 (48%) have occurred since 1990.

  • Like 3
  • Thanks 1
Link to comment
Share on other sites

28 minutes ago, donsutherland1 said:

Thanks Winterwx21.

The variability between snowy winters and those with a noted lack of snowfall could increase as we move through the transition.

Perhaps there is already somewhat of a signal starting to appear when it comes to measurable snowfall droughts. 6 of the 11 (55%) stretches of 300 or more days without measurable snow have occurred since 2000. If one throws in 1997-98, 7 of the 11 (64%) have occurred since 1990. If one expands the pool to cases of 290 days or more, 9/21 (43%) of such streaks have occurred since 2000 while 10/21 (48%) have occurred since 1990.

It’s possible that the 5 year moving average getting above 40” in NYC during the 2010s may have been a short term peak within a long term decline. 

7A1F4111-225F-459A-B5F5-BF22273EBE1E.thumb.jpeg.b2561fcb8663f6deec80493079402955.jpeg


1A253236-11CF-4C4D-AD90-52351BC37AEA.thumb.jpeg.08a4a483947a48a2d7eb41b601c739c7.jpeg

  • Like 3
  • Thanks 3
Link to comment
Share on other sites

27 minutes ago, donsutherland1 said:

I agree. 

The longer term decline would be more pronounced if the snowfall measurements were taken as frequently as today. 

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.

 

  • Like 4
  • Thanks 3
Link to comment
Share on other sites

1 hour ago, Snowshack said:

Nice little light snow shower on north shore of LI.   Colder surfaces already coated.  Might go unnoticed in a typical year but have face pressed against the window now.  

I was hoping that would happen in Central Park but to warm. That would have been an unexpected surprise if they got .01 of an inch.

Link to comment
Share on other sites

50 minutes ago, bluewave said:

It’s possible that the 5 year moving average getting above 40” in NYC during the 2010s may have been a short term peak within a long term decline. 

7A1F4111-225F-459A-B5F5-BF22273EBE1E.thumb.jpeg.b2561fcb8663f6deec80493079402955.jpeg


1A253236-11CF-4C4D-AD90-52351BC37AEA.thumb.jpeg.08a4a483947a48a2d7eb41b601c739c7.jpeg

The underlying data in that chart looks suspect.  Just one easy example, January average mean in 1977 was 22⁰.  1918 may have been the coldest, but it was a lot colder than 26⁰.  I'm not sure if the average max that year was that high.

Not arguing with the trend line, but this looks off.

Link to comment
Share on other sites

20 minutes ago, bluewave said:

The longer term decline would be more pronounced if the snowfall measurements were taken as frequently as today. 

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.

 

My understanding is that since 2015 is has reverted back and it's supposed to be the peak depth of accumulated new snow in a 24 hour period.  I recognize that may not be happening at at least some airports, but the apples to crabapples comparison also applies within the set of contemporary snowfall measurements.

  • Like 1
Link to comment
Share on other sites

20 minutes ago, NorthShoreWx said:

The underlying data in that chart looks suspect.  Just one easy example, January average mean in 1977 was 22⁰.  1918 may have been the coldest, but it was a lot colder than 26⁰.  I'm not sure if the average max that year was that high.

Not arguing with the trend line, but this looks off.

That’s the NYC DJF mean temperature trend. So the winter of 76-77 was correct. It was our last top 10 coldest winter.

Time Series Summary for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.
Rank
Season
Mean Avg Temperature 
Missing Count
1 1917-1918 25.7 0
2 1880-1881 26.5 0
3 1903-1904 27.3 0
4 1919-1920 27.4 0
5 1874-1875 27.7 4
- 1872-1873 27.7 0
6 1904-1905 28.1 0
7 1935-1936 28.3 0
8 1976-1977 28.4 0
- 1884-1885 28.4 0
- 1882-1883 28.4 0
9 1892-1893 28.6 0
- 1887-1888 28.6 0
10 1878-1879 29.0 2

 

  • Thanks 3
Link to comment
Share on other sites

  • Rjay unpinned this topic

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...