bluewave

That just goes to show how important the storm track and teleconnections are for snow here. Both winters featured that strong ridge stuck just north of Hawaii. So we had similar DJF snowfall even though this winter was 3 degrees warmer.

97-98 finished the whole snowfall season 7th lowest. They had the benefit of a -AO for DJFM that finally clicked for them on 3-22 with 5.0”. But this year we continue with the record SPV and +AO. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 1 1973-04-30 2.8 0 2 2002-04-30 3.5 0 3 1919-04-30 3.8 0 4 2020-04-30 4.8 72 5 1901-04-30 5.1 2 6 1932-04-30 5.3 0 7 1998-04-30 5.5 0 8 2012-04-30 7.4 0 9 1989-04-30 8.1 0 - 1878-04-30 8.1 0 10 1951-04-30 9.3 0

This is the same winter snowfall pattern as last year. It’s 9th lowest in snowfall and last winter finished 7th. Identical storm track pattern of cutter, hugger, and southern stream suppressed snowstorms. 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 Snowfall Missing Count 1 1997-1998 0.5 0 2 1918-1919 1.1 0 3 1972-1973 2.6 0 4 1931-1932 2.7 0 5 1991-1992 3.2 0 6 2001-2002 3.5 0 7 2018-2019 3.7 0 8 2011-2012 4.5 0 9 2019-2020 4.8 10 10 1989-1990 5.0 0

Last July was really close. 7-21-19 set or tied multiple record high temperatures at 99 degrees. Since the dew points were so high, the heat indices were similar to 7-22-11. The month also finished top 10 warmest around +3. JFK came within 1 degree of the all-time highest heat index at 114 degrees.

The record +AO just reinforces that background North Atlantic SST pattern that has been stuck in place for years. So we get record SST warmth off the East Coast and that cold pool south of Greemland.

You can see how quickly the models pull the ridge back to the Aleutians. This strong +EPO/-PDO is different from recent years. So this March may turn out warmer than we have experienced from 2017 to 2019.

Yeah, it will be interesting to see if we can pick up any snow this March. The lack of measurable snowfall since January 20th is different from recent years. This is the first time since 2002 with no measurable snowfall during the peak of the season. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Jan 20 to Feb 20 Missing Count 2020-02-20 T 3 2019-02-20 2.9 0 2018-02-20 5.9 0 2017-02-20 10.4 0 2016-02-20 31.5 0 2015-02-20 24.0 0 2014-02-20 42.1 0 2013-02-20 13.7 0 2012-02-20 4.5 0 2011-02-20 25.8 0 2010-02-20 17.3 0 2009-02-20 7.3 0 2008-02-20 2.8 0 2007-02-20 4.3 0 2006-02-20 26.9 0 2005-02-20 15.5 0 2004-02-20 11.0 0 2003-02-20 28.6 0 2002-02-20 T 0

The bar is set pretty low this year. All NYC needs is 2.6 inches of snow in March to make it the snowiest month of the season. It would be the 5th time since 14-15 if NYC can pull it off. 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 2014-2015 0.0 0.2 1.0 16.9 13.6 18.6 0.0 50.3 2015-2016 0.0 0.0 T 27.9 4.0 0.9 T 32.8 2016-2017 0.0 T 3.2 7.9 9.4 9.7 0.0 30.2 2017-2018 0.0 T 7.7 11.2 4.9 11.6 5.5 40.9 2018-2019 0.0 6.4 T 1.1 2.6 10.4 0.0 20.5 2019-2020 0.0 0.0 2.5 2.3 T M M 4.8

Just a remarkable shift to winter warmth since December 2015. Your area is also in 4th place. 3 top 4 finishes in 5 winters is as extreme as it gets. Time Series Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Number of Days Min Temperature > 32 Missing Count 1 2015-2016 44 0 2 2016-2017 40 0 3 2011-2012 38 0 - 2001-2002 38 0 4 2019-2020 36 11

NYC moves into 4th place for most winter days with the low temperature remaining above freezing. Today was the 49th day. 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 Number of Days Min Temperature > 32 Missing Count 1 2011-2012 58 0 - 1997-1998 58 0 2 2016-2017 55 0 - 2015-2016 55 0 - 2001-2002 55 0 3 1931-1932 53 0 4 1998-1999 49 0 2019-2020 49 11

Today is 19th day to reach 50 or warmer at Newark since December 22nd. It’s the 4th highest number of days for the time period. Feels like an early spring day out there. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Max Temperature >= 50 Dec 22 to Feb 17 Missing Count 1 2006-02-17 22 0 2 2012-02-17 21 0 - 1990-02-17 21 0 - 1932-02-17 21 0 3 1991-02-17 20 0 - 1950-02-17 20 0 4 1972-02-17 19 0 - 1933-02-17 19 0 2020-02-17 19 0

It’s been a real challenge with this Niña background pattern. This is the first time since the early 2010’s that the +EPO was strong enough to drop the -PDO this much.

We will have to make due with a much weaker -EPO than we had near the end of Feb and start of Mar last year. The AO is also much more positive this year coming off the current record breaking period. Looks like a transient +PNA before the ridge pulls back near the Aleutians.

Models have been too aggressive with the -EPO long range all winter. So this is no big surprise. It looks like we may get a transient +PNA near the start of March before the ridge pulls back closer to the Aleutians. We had a decent -EPO at this time last year which extended into March.

This is only our 6th time with no measurable snowfall during the peak snowfall season so far. It’s also the first time that this has occurred since 2002 and 1998. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Jan 20 to Feb 16 Missing Count 1 1890-02-16 0.0 0 2 2020-02-16 T 0 - 2002-02-16 T 0 - 1998-02-16 T 0 - 1981-02-16 T 0 - 1968-02-16 T 0 - 1900-02-16 T 0

Welcome to the all or nothing snowfall era. ISP has been either much above or much below since 2010. A midrange 20’s snowfall season has been missing. Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 2020-04-30 6.8 76 2019-04-30 12.8 0 2018-04-30 65.9 0 2017-04-30 39.3 0 2016-04-30 41.4 0 2015-04-30 63.7 0 2014-04-30 63.7 0 2013-04-30 46.9 0 2012-04-30 4.7 0 2011-04-30 55.3 0 2010-04-30 53.8 0

Even for the snowy 2010’s, March 2018 was a big outlier for late season snowfall. ISP broke the March record with 31.9 inches of snow. The interesting stat is that ISP has had only 19.6 inches of snowfall for the last 2 winters. So more than 10 inches less than March 2018. Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season 2017-2018 0.0 T 6.0 22.0 1.4 31.9 4.6 65.9 2018-2019 0.0 4.3 T 0.9 3.5 4.1 T 12.8 2019-2020 0.0 0.1 4.2 2.5 0.0 M M 6.8

14 degrees in NYC is the 4th warmest winter minimum temperature on record. ISP is 2nd warmest at 13 degrees. Albany comes in at 4th warmest and only the 8th time above 0. 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 Lowest Min Temperature Missing Count 1 2001-2002 19 0 2 1931-1932 18 0 3 1974-1975 15 0 4 2019-2020 14 14 - 2016-2017 14 0 - 2005-2006 14 0 - 2000-2001 14 0 - 1997-1998 14 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Lowest Min Temperature Missing Count 1 2001-2002 15 0 - 1997-1998 15 0 3 2019-2020 13 14 Time Series Summary for Albany Area, NY (ThreadEx) - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Lowest Min Temperature Missing Count 1 1931-1932 9 0 2 1936-1937 4 0 - 1889-1890 4 0 4 2019-2020 1 14 - 2016-2017 1 0 - 2005-2006 1 0 - 2001-2002 1 0 - 2000-2001 1 0

This Niña background pattern hasn’t worked for us the last 2 winters when combined with a struggling El Niño. We did fine with snowfall when combined with an actual La Niña in 16-17 and 17-18. So maybe we need a stronger El Niño or return to official La Niña in future winters to bring the snowfall back. The WPAC warm pool into the IO produces the Niña-like state. It also leads to stronger and more frequent MJO phase 5-7 events for us. So it’s no surprise that the CIPS shows a strong ridge near the Aleutians in the means for March. It has been stuck in that zone north of Hawaii for the last 2 winters.

We have seen plenty of hard AO /NAO reversals in recent years. Just look at the record -NAO from last April through November that suddenly reversed. The only other era with close to such an extreme +NAO +AO like we have now was 1989 to 1993. Most of those years featured a flip to more negative at some point in the spring or summer. But it’s difficult to speculate with the record breaking +AO phase right now.

The default summer pattern since 2010 has been above normal to record warmth and dewpoints. But the specific details this year look pretty complex. We currently have one strongest +AO patterns on record. Does this continue or reverse in time for the summer? The Niña -like ridge north of Hawaii has flipped the -PDO to most negative in years. Will this continue or can the El Niño try to come on to counter that Pacific pattern? Plenty of mixed signals going into the spring.

We would definitely need some help from the -EPO/+PNA as that Atlantic vortex is on steroids. Maybe the current SOI drop and +AAM spike could help out in this regard. Current SOI 15 Feb 2020 1009.07 1008.90 -21.95 -2.09 -4.47 14 Feb 2020 1009.59 1008.40 -17.05 -1.79 -4.32 13 Feb 2020 1010.64 1008.50 -12.49 -1.61 -4.11 12 Feb 2020 1012.36 1009.50 -9.03 -1.55

Seems like the records closer your area only go back to 1998. Time Series Summary for MONTGOMERY ORANGE COUNTY AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Lowest Min Temperature Oct 1 to Apr 30 Missing Count 1 2020-04-30 5 76 - 1998-04-30 6 95 3 2008-04-30 3 0 4 2007-04-30 2 0 - 2002-04-30 2 5 6 2017-04-30 0 0 - 2012-04-30 0 5 - 2010-04-30 0 1

The only long term records for SE interior NY appear to be POU. Looks like the last time the seasonal minimum was this high was back in 1998. Time Series Summary for Poughkeepsie Area, NY (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date Lowest Min Temperature Oct 1 to Apr 30 Missing Count 1 1937-04-30 10 4 2 1932-04-30 8 3 3 1998-04-30 6 8 - 1947-04-30 6 0 4 2020-04-30 5 76 - 1953-04-30 5 0 5 2008-04-30 3 0 - 2007-04-30 3 0 - 1944-04-30 3 0 6 2002-04-30 2 0 - 1992-04-30 2 0 7 2012-04-30 1 1