bluewave

It’s looking more and more like 2010 to 2018 was peak snowfall for NYC. But it it wasn’t advertised ahead of time. It’s only starting to become more obvious now that we are 6 years out from that period.

Yeah, we usually don’t find out the temperature threshold until it has already past. And there could be multiple thresholds which factor into our seasonal snowfall. One is the warming local average winter temperatures which result in declining snowfall averages over time. Another is a SST threshold in a part of the world like the MJO 4-7 regions which shift the storm tracks and lead to warmer local temperatures and lower seasonal snowfall. The record snowfall from 09-10 to 17-18 may have also been related to warming in some area of the planet which created the forcing patterns necessary for so many amazing snowfall seasons. But we may have surpassed that goldilocks snowfall zone when the 15-16 super El Niño resulted in the big jump in global temperatures. Almost like the 15-16 to 17-18 winters while warm, still had the lingering heavy snowfall pattern which seemed to emerge around 02-03 and peaked during the 2010s. Following the 17-18 winter, we have been been struggling with both warmer temperatures and unfavorable Pacific patterns leading to also unfavorable storm tracks and storm day temperatures. We did have a great 20-21 season but NYC couldn’t rival the 50”+ seasons like 09-10, 10-11, 13-14, and 14-15. January 22 was also a great month out on Long Island, but more disappointing around NYC to CNJ.

The 2010s will probably be remembered as the modern golden era for NYC snowfall. 10 year NYC average snowfall 49-50 to 58-59….19.9 59-60 to 68-69….32.0 69-70 to 78-79…..22.5 79-80 to 88-89…..19.7 89-90 to 98-99….24.4 99-00 to 08-09….28.0 09-10 to 18-19……37.9 19-20 to 20-29……13.2 so far

The black line is the 9 year moving average. It first peaked at 34.9° in 1933. Then there was a higher peak of 36.3° in 1958. It took until 1999 to exceed that at 36.4°. We are currently at 38.5° which is a full 2° warmer than any previous peak.

It’s the first time the 9 year winter moving average temperature in NYC went over 38.0°.

It matters to the extent that we have experienced a shift to much warmer winters with the +13 December 2015. The record warmth over the last 9 winters is unprecedented in our records. The winter current average of 38.6° is normal for parts of Virginia. We have never had a 9 winter average anywhere close to this warm before. Monthly Mean Avg Temperature for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Dec Jan Feb Season Mean 41.0 35.7 39.1 38.6 2023-2024 44.6 37.0 40.8 2022-2023 38.5 43.5 41.1 41.0 2021-2022 43.8 30.3 37.3 37.1 2020-2021 39.2 34.8 34.2 36.1 2019-2020 38.3 39.1 40.1 39.2 2018-2019 40.1 32.5 36.2 36.3 2017-2018 35.0 31.7 42.0 36.2 2016-2017 38.3 38.0 41.6 39.3 2015-2016 50.8 34.5 37.7 41.0

The big warm up for us comes by later next week as the block moves over to the Northeast. Then it will take a while for temperatures to get back closer to normal by mid-February.

All it took was one of the strongest omega blocks on record for this time of year to finally dry things out in early February.

That trough hanging back near the Baja would potentially act as a kicker favoring the main storm track across the Southeast and Mid-Atlantic. That’s what the long range EPS indicates for mid to late February. But it only takes one to stray a little further north for NYC to break its under 2” streak.

We are on track for the warmest first 2 weeks of February on record for the CONUS.

The historic winter warmth pattern since December 2015 continues. A record breaking 20 warmer winter months out of the last 26. NYC Jan 24..+3.3 Dec 23..+5.5 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

Probably better to keep expectations in check until we get closer to the mid portion of February. The first half of the month will be near record levels of warmth for North America. So even if the 500 mb pattern shifts like the models are indicating, there won’t be an immediate cold air source available. So it may take time to get the pattern back closer to average temperature wise. Then we will have to see where the storm track sets up. But since we will be in mid to late February, just cold enough will work with the right storm track.

Pretty impressive warmth for North America as a whole for the first half of February.

The weeklies are going all in on phase 8 as we approach the Presidents Day period.

That Arctic outbreak fit our recent pattern of having a near 60° day within a week of dropping under 10°. Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 2016-02-14 15 -1 2016-02-15 35 13 2016-02-16 54 35 2016-02-17 39 35 2016-02-18 36 27 2016-02-19 39 24 2016-02-20 61 39 Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 2023-02-04 27 3 2023-02-05 49 27 2023-02-06 52 34 2023-02-07 43 30 2023-02-08 53 39 2023-02-09 55 42 2023-02-10 61 45 Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 2022-12-24 15 7 2022-12-25 28 14 2022-12-26 29 18 2022-12-27 35 29 2022-12-28 47 33 2022-12-29 51 40 2022-12-30 62 46 Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 2019-01-21 14 4 0.00 0.0 0 2019-01-22 31 13 0.00 0.0 0 2019-01-23 52 31 T 0.0 0 2019-01-24 59 35 1.33 0.0 0 Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 2018-01-07 18 5 2018-01-08 31 17 2018-01-09 44 30 2018-01-10 43 30 2018-01-11 53 41 2018-01-12 61 44 Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 2015-01-04 56 41 2015-01-05 49 21 2015-01-06 22 19 2015-01-07 23 9 2015-01-08 21 8 Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 2014-01-06 55 19 2014-01-07 19 4 2014-01-08 22 9 2014-01-09 32 22 2014-01-10 37 30 2014-01-11 58 37

At least we are doing better than Buffalo.

Close to the cloudiest January since 1973 on Long Island at 63% now. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=45&network=NY_ASOS&zstation=ISP&hour=9&year=2024&month=1&_r=t&dpi=100&_fmt=png

We got a nice follow up storm to the east of NYC in early February pushing us up to around 40”. It gave JFK its first 40/40 winter. Data for October 1, 2015 through April 30, 2016 Click column heading to sort ascending, click again to sort descending. State Name Station Type Total Snowfall NY MIDDLE VILLAGE 0.5 SW CoCoRaHS 42.2 NY ISLIP-LI MACARTHUR AP WBAN 41.4 NY JFK INTERNATIONAL AIRPORT WBAN 41.4 NY CENTERPORT COOP 41.0 NY FLORAL PARK 0.4 W CoCoRaHS 40.9 Data for December 1, 2015 through February 28, 2016 Click column heading to sort ascending, click again to sort descending. State Name Station Type Mean Avg Temperature CT GROTON COOP 41.7 NY LAGUARDIA AIRPORT WBAN 41.6 NY NY CITY CENTRAL PARK WBAN 40.9 NY JFK INTERNATIONAL AIRPORT WBAN 40.8 NY MONTAUK AIRPORT WBAN 40.4 NY MOUNT SINAI COOP 40.3 NY FARMINGDALE REPUBLIC AP WBAN 40.2 NJ NEWARK LIBERTY INTL AP WBAN 40.0

The 15-16 winter was the real outlier for Decembers with a T or less of snow in NYC since 1950. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Dec Click column heading to sort ascending, click again to sort descending. Rank Year Total Snowfall Seasonal Snowfall 2011 0.0 7.4 - 2006 0.0 12.4 2023 T 2.3…so far - 2022 T 2.3 - 2018 T 20.5 - 2015 T 32.8 - 2001 T 3.5 - 1999 T 16.3 - 1997 T 5.5 - 1996 T 10.0 - 1994 T 11.8 - 1972 T 2.8 - 1971 T 22.9 - 1965 T 21.4 - 1953 T 15.8

We haven’t had a warm and dry winter since 2001-2002. All our warm winters since then have been wet with either snow or rain. Probably the most winter bike rides that I ever got in on the Long Beach boardwalk. Time Series Summary for NY CITY CENTRAL PARK, NY - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Total Precipitation Missing Count 1 1900-1901 4.22 0 2 2001-2002 4.88 0 3 1958-1959 5.28 0 4 1871-1872 5.41 0 5 1979-1980 5.45 0 6 1955-1956 5.97 0 7 1943-1944 6.13 0 8 1876-1877 6.40 0 9 1988-1989 6.45 0 10 1946-1947 6.59 0 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 2001-2002 41.5 0 2 2022-2023 41.0 0 - 2015-2016 41.0 0 3 2011-2012 40.5 0 4 1931-1932 40.1 0 5 1997-1998 39.6 0 6 2016-2017 39.3 0 7 2019-2020 39.2 0 8 1990-1991 39.1 0 9 1998-1999 38.6 0 10 1948-1949 38.5 0

Our only spring record snowfall in the 2020s so far happened in May.

We did much better in March during the 2010s than the 2020s so far. Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Mar Season Mean 0.1 0.1 2023 0.1 0.1 2022 0.4 0.4 2021 T T 2020 T T Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Mar Season Mean 6.0 6.0 2019 10.4 10.4 2018 11.6 11.6 2017 9.7 9.7 2016 0.9 0.9 2015 18.6 18.6 2014 0.1 0.1 2013 7.3 7.3 2012 0.0 0.0 2011 1.0 1.0 2010 T T

Only the 3rd time on record that northern suburbs like HPN haven’t dropped below 15° by 1-30. Time Series Summary for WESTCHESTER CO AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Lowest Min Temperature Oct 1 to Jan 30 Missing Count 1 2002-01-30 16 0 2 2024-01-30 15 1 - 1950-01-30 15 61 3 2020-01-30 13 2

The 500 mb pattern was closer to La Niña with a deep trough out West and a Southeast ridge. But the raging STJ with all the precipitation was classic El Niño. So a bit of a combination pattern as a function of the much further than west forcing for an El Niño in January.

I was talking about longer range and not inside day 7.