bluewave

Snowfall from earlier eras was undercounted by about 15-20%. So we need to increase the pre 1980s totals by about that much. But we do know that the big snowfall increases since the 1980s are legit since we have used the new measurement standards since then. So we need a snowfall reanalysis project for earlier snowstorms like they do with hurricanes. https://news.ucar.edu/14009/snowfall-measurement-flaky-history 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!

Living in a place like this must be a real experience during high wind events. https://dnyuz.com/2021/02/03/the-down-side-to-life-in-a-supertall-tower-leaks-creaks-breaks/ Many of the mechanical issues cited at 432 Park are occurring at other supertall residential towers, according to several engineers who have worked on the buildings. All buildings sway in the wind, but at exceptional heights, those forces are stronger. A management email explained that “a high-wind condition” stopped an elevator and caused a resident to be “entrapped” on the evening of Oct. 31, 2019 for 1 hour and 25 minutes. Wind sway can cause the cables in the elevator shaft to slap around and lead to slowdowns or shutdowns, according to an engineer who asked not to be named, because he has worked on other towers in New York with similar issues. One of the most common complaints in supertall buildings is noise, said Luke Leung, a director at the architectural firm Skidmore, Owings and Merrill. He has heard metal partitions between walls groan as buildings sway, and the ghostly whistle of rushing air in doorways and elevator shafts.

Yeah, someone should do a study including all our major snowstorms following the snowfall increase since the 02-03 winter. But just a few individual events listed in this thread show the increase related the to record SST warmth. The SST data should be combined with the increases in high latitude Atlantic and Pacific blocking that we have experienced over the same time period. We can probably add links between topical forcing and record Arctic warmth that can influence circulation patterns favorable for Northeast snowstorms.

Maybe they were referring to calendar day snowfall. Sometimes these distinctions aren’t always communicated clearly. Maximum 1-Day Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Value Ending Date Period of record: 1869-01-01 to 2021-02-02 1 27.3 2016-01-23 2 26.1 1947-12-26 3 24.1 2006-02-12 4 18.0 1872-12-26 5 16.5 1888-03-12 6 16.3 2003-02-17 7 15.8 1948-12-20 8 15.7 1941-03-08 9 15.5 1978-02-06 10 14.8 2021-02-01

Only the 4th time since 2010 that NYC went 40 days without reaching 55°. Number of Consecutive Days Max Temperature < 55 for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date Period of record: 2010-01-01 to 2021-02-02 1 65 2015-03-10 2 63 2011-02-13 3 40 2010-03-06 - 40 2021-02-03 4 33 2014-03-07 5 28 2018-03-29 6 26 2019-03-13 7 24 2010-01-24 8 23 2018-01-11 - 23 2013-01-13

This was the 11th snowstorm in the OKX forecast zones since 09-10 with a 20”+ max. 2021 Jan 31-Feb 2....Blomingdale, NJ.....26.1 2018 Mar 21-22...Patchogue, NY......20.1 Mar 8....New Farfield, CT..........26.8 2017 Mar 14...Montgomery, NY.......23.5 2016 Jan 23..JFK,NY.........................30.5 2015 Jan 26-27....Orient,NY.............28.5 2013 Feb 8....Upton, NY..................30.9 2011 Jan 11-12.......Meriden, CT....29.0 2010 Feb 25-26...Mount Hope, NY...27.5 Dec 26........Elizabeth, NJ........31.5 2009 Dec 19-20....Upton, NY..........26.3

The CPC GEFS AO forecast is correcting more negative with the extreme 500 mb blocking pattern. Looks like a -4 to -5 SD drop coming up. We have a nice track record for snowstorms following winter AO drops of this magnitude in the past. But as always, how soon the biggest storm arrives following these big AO drops can be quite variable.

We saw s SE jackpot shift from the12-17 event to the recent one on 1-31 to 2-2. BGM was the epicenter on 12-17 and that moved over to Northern NJ with the recent storm. The blocking was weaker in December so this allowed the low to tuck in over Southern NJ. The blocking intensified this past weekend and the low tucked in a little further east of ACY. Now with the strongest blocking of the whole season and years coming up, maybe the storm track will shift more SE toward the BM. So perhaps at some point this month ,we get the maximum snowfall totals from a KU setting up on Long Island to Southern New England.

The coming pattern is a great example of we need extreme blocking these days to get really cold around here. This will be one of the strongest west based blocks at 500 mb that we have seen during the month of February. Models have a 5.5 SD west based block in the coming days.

Yeah, that was in the era of much colder Februaries. When we get cold these days in February, it really stands out. The coldest recent February was 2015 with the weak El Niño. Our only February below 0° was during the Super El Niño in 2016. Those 1970s La Niñas were during our long 10”+ snowstorm drought from 1970 to 1977. This winter we already have 2. NYC February average temperature 1970-1980....32.4° 2010-2020....36.0°

Updated for this most recent event from Jan 31 to Feb 2, 2021. Bloomingdale, NJ 26.2 in 0100 AM 02/02 Trained Spotter

This could be our first La Niña winter in 30 years when NYC finishes with a cold departure in February and it’s the snowiest month. Even the 1995-1996 winter couldn’t pull off this feat. While it had a cold departure in February, the snowiest winter month was January. Just goes to show how competing influences during the last 3 winters overrode ENSO climatology. NYC La Ninas last 30 years Temperature departures Snowfall Season.....Dec....Jan....Feb 20-21......+1.7....+2.2.....? ................10.5.....2.1.....14.8...so far 17-18......-2.5......-0.9......+6.7 ................7.7......11.2......4.9 16-17......+0.8....+5.4.....+6.3 ................3.2.......7.9......9.4 11-12......+5.8....+4.7.....+5.6 .................0.0.....4.3........0.2 10-11......-4.7.....-2.9......+0.7 ...............20.1.....36.0.....4.8 08-09......+0.6.....-4.7.....+1.4 .................6.0......9.0......4.3 07-08.......+4.9.....+3.9....+0.5 .................2.9........T.........9.0 05-06.......-2.2.......+8.3.....+0.4 ..................9.7.......2.0......26.9 00-01......-6.4......+1.0....+0.6 ................13.4......8.3......9.5 99-00......+2.4......-1.3.....+3.5 ..................T.........9.5.......5.2 98-99.......+5.6.....+1.3.....+3.5 .................2.0........1.5.......4.7 95-96.......-5.1......-2.1.......-1.5 .................11.5......26.1......21.2

Walt, excellent post as usual. This is a map illustrating the February peak in Northeast snowstorms. The other thing that stands out in the research you provided is the historic number of storms during the last 15 years. The 51 Northeast snowstorms is off the charts counting all months in the snowfall season. 2006-2007 to 2020-2021.....51 storms 1991-1992 to 2005-2006.....30 storms 1975-1976 to 1990-1991.....25 storms 1960-1961 to 1974-1975......24 storms 1945-1946 to 1959-1960..... 20 storms

We are playing with loaded snow dice so below normal snowfall seasons are harder to achieve these days.

One or two down years in a row seems to be the max before snowfall rebounds in our snowier climate since 02-03.

More areas join the 20”+ club.

First double digit snowfall at ISP since 3-22-18.

You guys may have the best shot at 30” in the area with the right pivot.

Sneaky warm layer at 850 mb. SFC 1002 23 -0.5 -1.3 94 0.8 -0.8 13 24 272.4 273.0 272.2 281.8 3.46 1 1000 42 -1.0 -2.0 93 1.0 -1.4 14 21 272.2 272.7 271.8 281.1 3.31 2 950 449 -4.1 -4.1 100 0.0 -4.1 27 52 273.1 273.6 271.8 281.2 2.97 3 900 876 -1.6 -2.0 97 0.4 -1.7 52 70 279.9 280.5 276.7 290.1 3.67 4 850 1334 0.1 -0.3 97 0.4 -0.0 71 57 286.3 287.1 280.8 298.8 4.41 5 800 1818 -2.1 -2.9 94 0.8 -2.5 83 52 288.9 289.5 281.3 300.0 3.85 6 750 2327 -6.6 -6.6 100 0.0 -6.6 73 54 289.4 289.9 280.7 298.5 3.10 7 700 2868 -4.8 -4.8 100 0.0 -4.8 118 63 297.1 297.8 284.8 308.5 3.81

Parts of NNJ closing in on 25”.

First time this winter that the EPS weeklies corrected colder the closer we got to the forecast period. Feb 1-8 Feb 8-15

Temperature up to 31.3° here in SW with very light snow.

Snow got really light here in SW Suffolk and the temperature dropped to 30.6°.

Nice band of heavy snow across the whole South Shore of Suffolk. MacArthur/ISP HVY SNOW 31 30 96 NE29G43 29.87F VSB 1/4 WCI 16 Shirley HVY SNOW 31 28 89 NE12G24 29.90F VSB 1/4 WCI 22 Westhampton HVY SNOW 32 30 92 NE20G35 29.91F VSB 1/4 WCI 20