bluewave

Those snow piles at some of the Massapequa shopping centers look like small mountains.

37° and just plain rain here in SW Suffolk.

The core of the cold was focused over a smaller geographic region around the Plains during this extreme -AO episode. Notice how much more real estate the winter cold anomalies covered in 09-10, 76-77, and 69-70. So relative to other extreme -AO patterns, this was the warmest for our area.

The 500 mb blocking east of New England and the Canadian Maritimes just set a new all-time June to January record by a wide margin.

Yeah, even Fay and Isaias were tucked in during the hurricane season. This is a rare year for summer ridging east of New England and Canadian Maritimes continuing right into the winter. Record SSTs and ridging have been very impressive since last summer.

Yeah, we just didn’t have the supercharged STJ. The south based blocking seems to have helped to tuck in the storm tracks more than normal. The ridging poking down just east of New England allowed storms to track closer to Southern NJ. It also probably helped to give us about a degree or two of warming. My guess is that we would have the 50”+ of snow like Allentown as of today had the blocking been a little less south based.

It was colder than this winter. But the coldest departures were in the Southeast. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Season Mean Avg Temperature Missing Count 2020-2021 35.2 8 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Season Mean Avg Temperature Missing Count 2009-2010 33.8 0

This was only our 4th winter with a -1 or lower AO for each of the 3 winter moths. But notice how much more south based this one was vs the previous 3. So that made this the warmest winter of the 4. 20-21 09-10 76-77 69-70

Februaries have become really frontloaded for snow since 2011. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Feb 1 to Feb 14 Missing Count 2021-02-14 21.2 0 2020-02-14 T 0 2019-02-14 1.2 0 2018-02-14 0.5 0 2017-02-14 9.4 0 2016-02-14 2.6 0 2015-02-14 6.3 0 2014-02-14 25.7 0 2013-02-14 12.2 0 2012-02-14 0.2 0 2011-02-14 1.6 0 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Feb 15 to Feb 28 Missing Count 2021-02-28 4.4 8 2020-02-29 0.0 0 2019-02-28 1.4 0 2018-02-28 4.4 0 2017-02-28 0.0 0 2016-02-29 1.4 0 2015-02-28 7.3 0 2014-02-28 3.3 0 2013-02-28 T 0 2012-02-29 T 0 2011-02-28 3.2 0

We are finally on track for a colder winter month. This will be only the 4th colder winter month since the historic +13.3 December 2015. But we needed an extreme -AO pattern to pull it off. NYC Dec 15....+13.3 Jan 16....+1.9 Feb 16....+2.4 Dec 16....+0.8 Jan 17....+5.4 Feb 17....+6.3 Dec 17....-2.5 Jan 18.....-0.8 Feb 18....+6.7 Dec 18....+2.6 Jan 19....-0.1 Feb 19....+0.9 Dec 19....+0.8 Jan 20....+6.5 Feb 20....+4.8 Dec 20.....+1.7 Jan 21.....+2.2 Feb 21.....-2.9

We are in the top 5 for number of days in February with at least 1” of snow on the ground. This is a first for a moderate La Niña. The other years were neutral or El Niño’s. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Feb Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Snow Depth >= 1 1 1936 29 2 2015 28 3 1978 23 4 2014 22 - 2003 22 5 1969 20 5 2021 20 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Feb Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Snow Depth >= 1 1 2015 28 2 1978 22 3 2014 21 4 2021 20 5 2005 19

Yeah, the bar was lower during those recent years that you posted when March was the snowiest month. It will be interesting to see how we do this March. I added the March snowfall in NYC following a 20”+ Februaries since 1950. Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Feb Mar 2010 36.9 T 2014 29.0 0.1 2006 26.9 1.3 1994 26.4 8.1 2003 26.1 3.5 2021 25.6 M 1967 23.6 17.4 1978 23.0 6.8 1983 21.5 T 1996 21.2 13.2 1979 20.1 T

It’s pretty tough to have the snowiest month in March when when one of the winter months has 20”+.

March is one of those months the that snowfall in NYC is really sensitive to temperature. All the above normal snowfall Marches in NYC since 2010 have had a cold monthly temperature departure. The milder Marches had below normal snowfall.

50° is about the warmest that we can do over the next week. So EWR should remain near the top 5 lowest max temperature for Jan and Feb. We’ll have to see if Newark can sneak in higher than 53° before the end of the month. Very odd to have such a low maximum temperature with a mild average DJF above freezing. KEWR GFSX MOS GUIDANCE 2/20/2021 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 SAT 20| SUN 21| MON 22| TUE 23| WED 24| THU 25| FRI 26| SAT 27 CLIMO X/N 34| 19 38| 24 41| 33 45| 36 50| 36 44| 25 38| 21 41 27 45 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Jan 1 to Feb 28 DJF Average Temperature 1 1969-02-28 48 31.7° 2 1941-02-28 50 32.1° 3 1968-02-29 51 32.0° - 1963-02-28 51 29.4° 4 2003-02-28 52 30.7° 5 2021-02-28 53 34.4°

This has been the one of the most tucked in storm track snowy winters of the last 30 years. Very unusual for NYC not to have 50” when ABE does. So you can see how rare it is to have a snowy season with the storm tracks so close to Southern NJ. Time Series Summary for Allentown Area, PA (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date ABE Snowfall NYC Snowfall 1 1994-04-30 75.2 53.4 2 1996-04-30 71.4 75.6 3 2014-04-30 68.1 57.4 4 2010-04-30 59.8 51.4 5 2003-04-30 54.4 49.3 6 2021-04-30 53.2 38.2 7 2015-04-30 50.1 50.3

The North Atlantic can influence the Indian Ocean also.

Maybe that’s due to the recent Arctic outbreak occurring in a much warmer would with more available moisture for heavy snowfall.

We were just discussing in the other thread how the strongest Arctic outbreaks have been focused in the Plains recently. Notice how the Plains are one of the few parts of the world that will see a drop in the average temperatures when the new 30 year normals come out. Also matches the warmer temperatures here this week relative to the 1989 and 1899 Arctic outbreaks.

Yeah, Atlantic, Pacific, and Indian Ocean warming are all important. We just don’t have the seasonal forecast models that can accurately handle those interactions. Sometimes one model may get a part of the forecast right. But miss other important drivers.

It certainly does make long range seasonal forecasting more interesting. Looks like the oceans have warmed to the point that it’s interfering with the expected ENSO responses. Absent better seasonal models and more computer power, seasonal forecasts will be even more challenging than they were before.

Yeah, such a low maximum temperature for January and February is really out of place. The current max in NYC since January 1st is only 51°. That’s the 4th coldest on record. It would be the coldest max for Jan and Feb with such a mild DJF average temperature. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Jan 1 to Feb 28 DJF average Temperature 1 1969-02-28 48 32.9 2 1941-02-28 49 33.0 3 2003-02-28 50 31.2 - 1968-02-29 50 31.2 4 2021-02-28 51 35.3 - 1963-02-28 51 29.9 - 1920-02-29 51 27.4 - 1895-02-28 51 30.2 5 1908-02-29 52 33.0 - 1879-02-28 52 29.0 6 1958-02-28 53 33.2 - 1923-02-28 53 29.9 - 1905-02-28 53 28.1 - 1901-02-28 53 31.7 - 1899-02-28 53 31.3 - 1881-02-28 53 26.5 - 1871-02-28 53 31.2

Steady light snow now in SW Suffolk with larger flakes and 32°.