NYC's 15 year snow average is now 34.00"

[yhbrooklyn]

The 2000-01 through 2014-15 is now the snowiest in over 100 years.

The last 15 year period to be over 34" was 1892-93 through 1906-07.

Impressive.

It is also the 5th snowiest 15 year period since records began.

In order to get to #1, we'd have to get another 13" this year, so low chances.

[RU848789]

In order to get to #1, we'd have to get another 13" this year, so low chances.

 

Or replace the zookeeper, lol...

 

Pretty amazing stat and the whole period occurring at the same time the internet exploded on every level, including meteorological forums, like this one, and all the previous incarnations.  There's now a whole generation of people under 20-25 who really have never known what "normal" snowfall is like.  When we go back to lower snowfall years/decades they're really going to struggle, I think, as it's easy to feel like this amount of annual snowfall is normal.  It ain't.  

[Allsnow]

Awesome

[jm1220]

NYC has essentially become what Allentown or Harrisburg, PA is long-term over the past 15 years. It's been an amazing stretch for I-95, particularly from Philly north since 2000. Climo hits hard though, and eventually the pattern will have to break to the long term mean. 

[LongBeachSurfFreak]

NYC has essentially become what Allentown or Harrisburg, PA is long-term over the past 15 years. It's been an amazing stretch for I-95, particularly from Philly north since 2000. Climo hits hard though, and eventually the pattern will have to break to the long term mean.

Or this is the new norm. No one can say definitely on either side but I personally think it is.

[Cfa]

I find stuff like this very interesting, climate interests me just as much as weather does. I wonder why it's been so snowy.

[jm1220]

Or this is the new norm. No one can say definitely on either side but I personally think it is.

We'd have to look back much further than we can now to answer that. Of course, Long Island served as the ultimate R/S line once since the north shore and south shore were literally divided by a mile tall wall of ice. Imagine that!!

[Rjay]

Or this is the new norm. No one can say definitely on either side but I personally think it is.

+1

[EasternLI]

Or this is the new norm. No one can say definitely on either side but I personally think it is.

 

Agree

[nzucker]

Or this is the new norm. No one can say definitely on either side but I personally think it is.

Climate change may have a small role in increased snowfall amounts in the largest storms, yet I doubt NYC' owes its snowy decade to AGW. The tendency for northern latitudes to receive more snow in a warner world is doubtless true, yet 10-15 years in one city is too short a time and too small an area. Climo will revert to norm and NYC will see a few years of below average snowfall just as 06-07 and 07-08 happened after four seasons ofv40"+....interior areas like the Poconos and NNJ will go back to benefiting from the rain-snow line. There is a reason NYC doesn't average 35" a season permanently and you will see that reason sooner or later.

[jm1220]

Climate change may have a small role in increased snowfall amounts in the largest storms, yet I doubt NYC' owes its snowy decade to AGW. The tendency for northern latitudes to receive more snow in a warner world is doubtless true, yet 10-15 years in one city is too short a time and too small an area. Climo will revert to norm and NYC will see a few years of below average snowfall just as 06-07 and 07-08 happened after four seasons ofv40"+....interior areas like the Poconos and NNJ will go back to benefiting from the rain-snow line. There is a reason NYC doesn't average 35" a season permanently and you will see that reason sooner or later.

That's often missed, IMO. The pattern has favored big coastal storms that have had big snow totals on the coast, but fewer storms that favor the interior like were common in the 70s, 80s, and 90s. Storms with an Appalachian heavy snow axis are less common now than before 2000. That's why I say that if that axis was shifted a few hundred miles over the last decade, weenies would be in near riot-mode constantly. The spine of the Appalachians hasn't enjoyed the huge winters the coast has in general. 

[FreeRain]

The 2000-01 through 2014-15 is now the snowiest in over 100 years.

The last 15 year period to be over 34" was 1892-93 through 1906-07.

Impressive.

 

 

Amazing stat considering the notorious Zookeeper.

[Guest Pamela]

Comparative snow totals in the Mid Atlantic & Northeast in recent years...

 

Total Snowfall
2000-01 through 2014-15 (through March 6th, 2015) (Last 15 Years)

Boston / Logan Airport: 785.5 inches / average 52.37 inches
Brookhaven Lab, L.I. / Upton: 648.6 inches / average 43.24 inches
New York City / Central Park: 510.0 inches / average 34.00 inches
Philadelphia / International Airport: 412.9 inches / average 27.53 inches
Baltimore / BWI Airport: 319.5 inches / average 21.30 inches
Washington / Reagan Airport: 233.0 inches / average 15.53 inches

[Guest Pamela]

Comparative snow totals in the Mid Atlantic & Northeast in recent years...

 

Total Snowfall

2000-01 through 2014-15 (through March 6th, 2015) (Last 15 Years)

Boston / Logan Airport: 785.5 inches / average 52.37 inches

Brookhaven Lab, L.I. / Upton: 648.6 inches / average 43.24 inches

New York City / Central Park: 510.0 inches / average 34.00 inches

Philadelphia / International Airport: 412.9 inches / average 27.53 inches

Baltimore / BWI Airport: 319.5 inches / average 21.30 inches

Washington / Reagan Airport: 233.0 inches / average 15.53 inches

 

All the stations listed are well above normal for the last 15 years; with the exception of Washington DC...which is very close to normal. Actually Baltimore is not too far from normal either. 

[Guest Pamela]

Comparative snow totals in the Mid Atlantic & Northeast in recent years...

 

Total Snowfall

2000-01 through 2014-15 (through March 6th, 2015) (Last 15 Years)

Boston / Logan Airport: 785.5 inches / average 52.37 inches

Brookhaven Lab, L.I. / Upton: 648.6 inches / average 43.24 inches

New York City / Central Park: 510.0 inches / average 34.00 inches

Philadelphia / International Airport: 412.9 inches / average 27.53 inches

Baltimore / BWI Airport: 319.5 inches / average 21.30 inches

Washington / Reagan Airport: 233.0 inches / average 15.53 inches

 

The absurd anomalies in Boston first manifest during the 1992-93 winter....they began to show up down the coast at Upton one winter later, 1993-94. 

[doncat]

15 year normal at this station is 35"... There were four clunkers during that span with 15" or less.

[Jb1979]

Chiming in from the Philly area with a breakdown I did of the past 100 winters at KPHL. Definitely relevant for you guys since due to our proximity our patterns longterm are closely related even if there is the occasional winter where absurd blocking gives us significantly more than you or the temp gradient sets up too far north for us but buries you.

 

Anyway a graph I did is below. The green line is the 100 year mean. The yellow shaded area is +15/-15 from the mean or what I consider "normal" winters. The last 20 years are shaded in red. The big takeaway is that the past 20 years have been much mire volatile - with fewer normal winters and more "extreme" winters. Thought you might find it interesting.

[Isotherm]

15 year normal at this station is 35"... There were four clunkers during that span with 15" or less.

 

 

15 year normal is an impressive 36.4" here, with also 4 terrible winters of < 15" (01-02, 06-07, 07-08, 11-12). Really phenomenal for a 15 year period to contain only 4 well below normal winters.

 

I'm of the opinion that we're going to see tendency / continuance of more high latitude blocking episodes in the coming winters due to the decline in solar parameters overall. There's solid scientific research that correlates the weakened solar constant w/ an increased propensity for high latitude blocking. Thus, I do believe we've entered a new climatic normal to some extent, such that snowfall will generally be elevated in comparison to the 1970-2000 30 year time frame. If one examines the lower solar period of the 1700s and part of the 1800s, one would find a high frequency of cold / snowy winters. There will continue to be clunkers with < 15" of snowfall, but I believe on the whole, our snowfall averages will continue to slowly increase over the course of the coming decade. My call from several years ago was that the 2010-2020 decade would actually prove snowier than 2000-2010 in NYC. We'll see how the second half of the decade plays out.

[wxman]

To state the obvious, the snowy 15 year period standing alone creates a new, higher average snowfall over any given period of examination.  

[coastalplainsnowman]

Just curious, any stats on where the standard deviation for the last 15 years stacks up against other 15 year periods?  Probably among the highest I would think.

 

Also, any idea what the least snowy 15 year average was over that timeframe?  Thanks.

[rsteff]

Not surprised at all

[SomeWeatherGeek]

When people mentioned El Niño earlier this year, I automatically thought we'd get screwed like 97-98 winter which NYC ended up with only a measly 5. Thank Goodness we ended up with a backloaded winter which was very impressive. Coldest winter I ever remember. I think the next snow event has to be a dynamic system such as a cutter heavy thump of snow to rain or a dynamic nor'easter, otherwise if we end up with a SWFE we may get a sheared out system that would mostly be a taint type of system. Sun angle takes into effect and much higher temperatures we've had this winter. I think we'll get a cutter than gives us a 3-6 followed by slop and rain. Also it would help if the system came in at night. Still cold out there even though the sun is out and about.

[bluewave]

There is no doubt about the amazing run of heavy snowstorms and high snowfall seasons

since 2000. You could go back to the 94-94 and 95-96 seasons to start the period.

But the latest research indicates that past periods were snowier than we suspected

due to improved ways of measuring snowfall since then.

 

 

http://www2.ucar.edu/atmosnews/perspective/14009/snowfall-measurement-flaky-history

 

 

SNOWFALL MEASUREMENT: A FLAKY HISTORY Many pre-1990 numbers would be higher using current methods

 

 

Matt Kelsch • January 28, 2014 | As this week’s blizzard rumbled toward the U.S. Northeast, many media outlets posted the top-10 snow events for major cities. An unusual number of snowfalls in those top 10 lists have been within the last 20 years, even in cities that have records going back to the 1800s. Why is that? Could it be climate change? Are other factors involved?

 

As a hydrometeorological instructor in UCAR’s COMET program and a weather observer for the National Weather Service, I am keenly interested in weather trends. In this case, climate change is an important factor to explore, since we know that the heaviest precipitation events have intensified in many parts of the world (see related story: Torrents and droughts and twisters - oh my!).

But when we turn to snowstorms in the Northeast, or elsewhere in the U.S., there is an additional factor at work when comparing modern numbers with historical ones. Quite simply, our measuring techniques have changed, and we are not necessarily comparing apples to apples. In fact, the apparent trend toward bigger snowfalls is at least partially the result of new—and more accurate—ways of measuring snowfall totals. Climate studies carefully select a subset of stations with consistent snow records, or avoid the snowfall variable altogether.

Official measurement of snowfall these days uses a flat, usually white, surface called a snowboard (which pre-dates the popular winter sport equipment of the same name). The snowboard depth measurement is done ideally every 6 hours, but not more frequently, and the snow is cleared after each measurement. At the end of the snowfall, all of the measurements are added up for the storm total. 

NOAA’s cooperative climate observers and thousands of volunteers with the Community Collaborative Rain, Hail and Snow (CoCoRaHS), a nationwide observer network, are trained in this method. This practice first became standard at airports starting in the 1950s, but later at other official climate reporting sites, such as Manhattan’s Central Park, where 6-hourly measurements did not become routine until the 1990s.

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.

Matt Kelsch is a hydrometeorologist in UCAR's COMET Program. He specializes in weather and climate events involving water, such as floods, droughts, rain, hail, or snow. Kelsch develops and delivers educational materials designed for both domestic and international groups including National Weather Service forecasters, the military, the World Meteorological Organization, university students and faculty, government agencies, and private industry.

 

 

[yhbrooklyn]

When people mentioned El Niño earlier this year, I automatically thought we'd get screwed like 97-98 winter which NYC ended up with only a measly 5. Thank Goodness we ended up with a backloaded winter which was very impressive. Coldest winter I ever remember. I think the next snow event has to be a dynamic system such as a cutter heavy thump of snow to rain or a dynamic nor'easter, otherwise if we end up with a SWFE we may get a sheared out system that would mostly be a taint type of system. Sun angle takes into effect and much higher temperatures we've had this winter. I think we'll get a cutter than gives us a 3-6 followed by slop and rain. Also it would help if the system came in at night. Still cold out there even though the sun is out and about.

1997-98 was even worse than you think. We got 5" on March 22 which melted by noon. Actual winter only had half an inch. Season total was 5.5".

 

 

Just curious, any stats on where the standard deviation for the last 15 years stacks up against other 15 year periods?  Probably among the highest I would think.

 

Also, any idea what the least snowy 15 year average was over that timeframe?  Thanks.

 

Lowest 15 year average is 20.11" from 1978-79 through 1992-93. I'm sure that surprises no one who recalls the 80s.

[LongBeachSurfFreak]

1888 is the ultimate under measurement in NYC. There was no measurement until well after the storm ended. With tremendous winds an settling I think it was at least a 30" storm at cpk using modern snow board

[uncle W]

Hello from Florida...snow depth measurements should be the same as in the past and three of the last five years are among the greatest of a

L time...

[yhbrooklyn]

Hello from Florida...snow depth measurements should be the same as in the past and three of the last five years are among the greatest of a

L time...

Snow measurements in Florida should be relatively easy.

[jm1220]

All the stations listed are well above normal for the last 15 years; with the exception of Washington DC...which is very close to normal. Actually Baltimore is not too far from normal either. 

Could you list Dulles? It would be interesting to see Reagan Airport in a snowhole vs. Dulles which is more like PHL climo-wise.

[Guest Pamela]

1888 is the ultimate under measurement in NYC. There was no measurement until well after the storm ended. With tremendous winds an settling I think it was at least a 30" storm at cpk using modern snow board

 

That's not the case...I have the commentary of the NWS NYC in front of me in print; (could not find it online)...the observer on duty those 3 days wrote extensively (several hundred words):  Excerpts from the report:

 

March 11: Cloudy during the morning; light rain began at 12:50 PM and ended at 2:50 PM; began again at 3:25 PM; and ended at 4:57 PM; began again at 6:45 PM and continued. 

 

March 12: The light rain turned into snow at  12:10 AM and continued throughout the day, with high northwesterly winds reaching a maximum velocity of 48 mph.

The high winds began during the early morning.  At 3:00 AM the anemometer wires were blown down, and owing to the cold weather and the severe driving snow it was not possible to raise them up and in working order until 10:00 AM.....snowfall 16.5 inches.

Cloudy sunset.

 

March 13: The light snow ended at 5:55 AM ; began again at 1:55 PM and ended at 7:05 PM; began again at 8:15 PM in flurries and continued.  High westerly winds throughout the day.   Halyards frozen; impossible to display flags,  (Weather) Office constantly filled with reporters and the public seeking the latest information.  Snowfall: 3.0 inches.  Cloudy sunset.

 

March 14: The light snow ended at 3:40 AM; began again 6:25 AM and ended at 7:15 AM; began again at 10:40AM and ended at 2:50 PM.  Fresh to brisk northwesterly winds...  Business reviving...railroads still blocked by snow but clearing tracks rapidly.  Ferries running regularly.  Snowfall 1.4 inches.  Yellow sunset. 

[Guest Pamela]

1888 is the ultimate under measurement in NYC. There was no measurement until well after the storm ended. With tremendous winds an settling I think it was at least a 30" storm at cpk using modern snow board

 

Most of northern NJ saw in the 20 to 25 inch range like NYC per the observers of the day...it was only until one got into CT (west of New London County) that the incredible snow amounts were recorded...46" at New Haven...50" at Middletown...50" (approx.) in the mid Hudson Valley at Albany.  Far to the south, Cape May saw but 10"...and parts of Sussex County saw as little as 12". 

This makes sense; as western & central New England being the focal point for the heaviest axis of precip...being just to the west of the sharp front separating easterly winds and maritime air from the arctic air west of the boundary and a north to northwesterly flow.