bluewave

A study out today expands on the rapid SST warming off the Northeast Coast that has been a big player for us. https://www.washingtonpost.com/climate-environment/2021/02/25/atlantic-ocean-currents-weakening-amoc-gulf-stream/

Looks like the EPS begins the first week of March with an omega and east based blocking pattern. Has near to below average temperatures in the Northeast. Sometimes these shorter wavelengths in early March can surprise. So it may take the models time to work out the storm details. March 1-8

Yeah, the strong blocking pattern this winter was the dominant factor for us. But you can see how the unfavorable MJO phases pretty much ran the table during the 18-19 and 19-20 winters.The pattern was more split between the unfavorable MJO and blocking during 15-16, 16-17, and 17-18 winters.

That’s a good question. The MJO data goes back to the 1970s. February 2010 had the MJO 7 going more quickly into phase 8. The MJO also went fairly quickly into a phase 8 in 1978. This year the MJO has been stuck in 6-7 for more than a month. But we have seen bigger AO swings in recent years. We also have the warmer WAPAC SSTs favoring longer and more amplified phases 4-7.

One of the more unusual weather records this month was how rapidly the AO rose from below -5 to over +2 today. I think this is why the models backed off their snowier forecasts that they had for mid to late February. The last 3 Februaries that went below -5 were 2010, 1978, and 1969. The AO didn’t reach +2 during 2010 until November. The AO made it to +2 in mid-March 1978. It also took longer in 1969 to get back to plus +2 in late October. https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.ao.index.b500101.current.ascii

Yeah, temperatures look to drop back into the 30s this evening.

JFK is at 62 days so far. The record is 113 days with a low under 40 set during 00-01.

JFK snuck in a 53° back on January 2nd. So that is still the high for January and February. This is the first 60+ day streak with a low under 40 since the last one ended in March 2019.

Looks like we have a chance at our first January and February that could stay below 55° since 2003. Models have highs in the low 50s on Saturday. So warm ups remain tame by recent standards. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Highest Max Temperature Jan 1 to Feb 28 Missing Count 2021-02-28 54 4 2020-02-29 69 0 2019-02-28 65 0 2018-02-28 78 0 2017-02-28 70 0 2016-02-29 61 0 2015-02-28 56 0 2014-02-28 58 0 2013-02-28 61 0 2012-02-29 62 0 2011-02-28 67 0 2010-02-28 57 0 2009-02-28 65 0 2008-02-29 68 0 2007-02-28 72 0 2006-02-28 64 0 2005-02-28 66 0 2004-02-29 59 0 2003-02-28 50 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Ending Date Highest Max Temperature Jan 1 to Feb 28 Missing Count 2021-02-28 54 4 2020-02-29 70 0 2019-02-28 68 0 2018-02-28 80 0 2017-02-28 74 0 2016-02-29 65 0 2015-02-28 56 0 2014-02-28 61 0 2013-02-28 66 0 2012-02-29 64 0 2011-02-28 71 0 2010-02-28 59 0 2009-02-28 66 0 2008-02-29 69 0 2007-02-28 72 0 2006-02-28 63 0 2005-02-28 67 0 2004-02-29 62 0 2003-02-28 52 0

Impressive thaw pattern across the US.

It looks like NYC finally had a 40° low temperature today. This was the first time since December 24th. It’s also the first time going over 60 days since 2015. https://www.wrh.noaa.gov/mesowest/getobext.php?sid=KNYC&table=1&num=168&banner=off Number of Consecutive Days Min Temperature < 40 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 2021-02-23 1 63 2015-03-08 2 61 2021-02-23 3 56 2013-03-10 4 46 2011-02-16 5 41 2010-03-07 6 38 2014-02-21 7 29 2019-02-03 8 27 2018-03-28 9 26 2019-03-13 10 23 2017-02-18

Updated for February 2021.

Fairly tame warm up by recent late winter standards. Temperatures should rise to around 50° Wednesday. Maybe a few degrees warmer Saturday. So we are on track for our first January and February without any 60 degree days since 2014 and 2015. If both Newark and NYC remain below 55°, then it would be the first time since 2003. Newark may try to reach the top 10 for longest streak under 55° days. Newark is currently at 12th longest with 60 days. Number of Consecutive Days Max Temperature < 55 for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date 1 111 1963-03-23 2 87 1941-03-22 3 84 2003-03-14 4 83 1956-02-24 5 78 1969-03-16 6 77 1977-02-22 7 76 1968-03-07 - 76 1948-02-17 8 69 1971-02-11 9 65 2015-03-10 10 63 2011-02-13 - 63 1940-02-11 11 60 2004-02-27 - 60 2021-02-23

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