bluewave

Yeah, we usually have the heaviest snowfall rates right before we start mixing with sleet. But this time the heaviest rates came after. So a nice surprise.

This is currently my heaviest snow rate of the whole season in SW Suffolk. Started with giant 1.5 “ diameter snowflakes. Now I have visibility under .2 mile in very heavy snow.

Looks like some really large 56 DBZ flakes near Far Rockaway.

Biggest snowflakes of the season here in SW Suffolk in excess of 1” diameter.

Sleet and crunchy rimed flakes here in SW Suffolk now.

The 3km NAM did pretty good.

Yeah, showing up on radar now.

Moderate snow now in SW Suffolk and 26°.

Somebody is probably going 2” per hour in that 40 DBZ band.

Yeah, the more amped up storm a few days ago became a stronger 50/50 low than forecast allowing more confluence over New England.

The high over New England really came on stronger over the last 3 days. The dewpoints are just in the single digits for Boston. So you can see why the bands are struggling to get north of our area right now. Boston CLOUDY 24 5 44 N6 30.53R WCI

Steady light snow here in SW Suffolk with a light dusting on the ground.

This winter has probably been the most Nino-like moderate La Niña that we have ever seen. The +PNA for much of the winter has been classic El Niño. The warmer to colder and snowier progression by later in the winter is also El Niño. The -5 AO AO drop this February only occurred in the past during El Niño winters. Funny how the last two El Niño winters in 18-19 and 19-20 had more Niña-like patterns. So something is going on that is altering the expected ENSO response during the last three winters. Probably related to the anomalous warm SST blobs that have popped up all around the globe. The location of marine heatwaves need to be taken into account. But the interactions may be beyond what seasonal forecasts can resolve. The most reliable relationship between snowy winters and the -AO has worked out nicely this winter or us . February -5 AO readings and ENSO 2021.....-1.2 2010.....+1.6 1978.....+0.8 1969.....+1.1

This has to one of the most backloaded February La Ninas for snow and cold across the US that we have ever seen. Gives new meaning to competing winter influences. Makes it very difficult to produce seasonal forecasts during the fall based solely on ENSO and past analogs. It’s the third consecutive winter that forecasts went against ENSO expectations. Even though 15-16, 16-17, and 17-18 were extreme winters for their weather swings, at least they retained the El Niño and La Niña expected progressions.

This year really takes the prize for snow extent volatility. We went from record highs in October to record lows and now we are on top again. Also interesting how a version of the October pattern repeated in February. https://www.star.nesdis.noaa.gov/smcd/emb/snow/HTML/snow_extent_plots.html

Upton has had 11 years reach 40”+ since 2003 and 9 years reach 50”+. 2002 2003 0 2 11.5 5.8 31.8 5.5 5.5 62.1 2003 2004 0 0 25 22 2.2 11 0 60.2 2004 2005 0 0.5 13 29 20 16 0 78.5 2005 2006 0 1.5 7 4 14 4 0 30.5 2006 2007 0 0 Trace 0.5 3.5 5.5 0 9.5 2007 2008 0 Trace 3 0.5 7 1 0 11.5 2008 2009 0 Trace 10.9 12.1 5.2 14.8 0 43 2009 2010 0 0 26.3 12.7 28.4 0.4 0 67.8 2010 2011 0 0 19.8 35.7 4.7 1.3 0 61.5 2011 2012 0 0 0 5.5 0 0 0 5.5 2012 2013 0 1.1 1.4 4.7 35.8 8.8 0 51.8 2013 2014 0 0.2 5.4 24.8 23.9 3.2 0 57.5 2014 2015 0 0 0.3 22.8 15.2 23.9 0 62.2 2015 2016 0 0 Trace 18.8 14.3 2.7 0.1 35.9 2016 2017 0 0 4.1 14.3 15.8 7.9 0 42.1 2017 2018 0 0 7.4 21.2 1.3 21 4.3 55.2 2018 2019 0 4.6 Trace 1 3.5 6 0 15.1 2019 2020 0 2.19 3.8 2.7 0 0 0 8.69

A 40” season used to be a big deal before 2003. Now it’s just another above average season. This would make 10 years reaching 40” since 2003. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 2021-04-30 33.8 74 2020-04-30 4.8 1 2019-04-30 20.5 0 2018-04-30 40.9 0 2017-04-30 30.2 0 2016-04-30 32.8 0 2015-04-30 50.3 0 2014-04-30 57.4 0 2013-04-30 26.1 0 2012-04-30 7.4 0 2011-04-30 61.9 0 2010-04-30 51.4 0 2009-04-30 27.6 0 2008-04-30 11.9 0 2007-04-30 12.4 0 2006-04-30 40.0 0 2005-04-30 41.0 0 2004-04-30 42.6 0 2003-04-30 49.3 0

The 1980s Arctic outbreaks covered more real estate than this one. You can see how the US average temperatures on the peak outbreak days were colder in 1983 and 1989. Brian B has a fantastic post below comparing some of the strongest Arctic outbreaks back to 1899.

I agree with you. The US is much warmer now that it was during the 1980s and earlier times. The only area of small cold departures during the last 10 winter average has been focused over the Upper Plains. You can see how much more expansive the cold was across the US during the 1980s. So it makes sense that this historic cold outbreak was focused closer to the Plains. The 1989 Arctic outbreak matched the 1980s cold pattern which was more spread out over a wider area.

This was the 9th longest streak under 50° at Islip before the 50s today. Number of Consecutive Days Max Temperature < 50 for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Run Length Ending Date Period of record: 1963-09-05 to 2021-02-15 1 79 1968-03-10 2 62 2011-02-13 3 57 1977-02-15 4 54 2004-02-27 5 49 2015-03-08 6 48 1990-01-15 7 47 1985-02-18 8 45 1969-03-17 9 44 2021-02-15 - 44 1981-01-26

Looks like the Euro is overdoing the confluence in New England. So that 6”+ zone will probably bump north in later runs similar to the other guidance today.

Long Island will always eventually changeover with more tucked in storm tracks.

The forecast soundings look a little better this morning. Maybe we could sneak in a 3-6” front end thump at the coast before the sleet arrives. The high over New England is positioned better. We’ll see if we can hold this in coming days.

But the bigger snow piles are still doing OK.