bluewave

That’s why 1995-1996 remains the undisputed seasonal snowfall champion. Even with our snowier climate since 2003, it’s been too difficult to get more than 2 months with 10”+ snowfall during any given season in NYC. 2010-2011 may have come closest if we could have kept the snowy pattern going another month or so. 1995-1996 was the last time NYC had 4 months with 10”+ snowfall and 2 with 20”+ in a single season. Part of the issue is that winters have become warmer since the snowfall increase in 2002-2003. So we can’t get the extended cold from late November to April like we had that year. It’s also very difficult to get a perfect Atlantic and Pacific blocking pattern for such a long duration like we had in 1995-1996. 10”+ snowfall months bolded 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 1995-1996 0.0 2.9 11.5 26.1 21.2 13.2 0.7 75.6 1996-1997 0.0 0.1 T 4.4 3.8 1.7 T 10.0 1997-1998 0.0 T T 0.5 0.0 5.0 0.0 5.5 1998-1999 0.0 0.0 2.0 4.5 1.7 4.5 0.0 12.7 1999-2000 0.0 0.0 T 9.5 5.2 0.4 1.2 16.3 2000-2001 T 0.0 13.4 8.3 9.5 3.8 0.0 35.0 2001-2002 0.0 0.0 T 3.5 T T T 3.5 2002-2003 T T 11.0 4.7 26.1 3.5 4.0 49.3 2003-2004 0.0 0.0 19.8 17.3 0.7 4.8 0.0 42.6 2004-2005 0.0 T 3.0 15.3 15.8 6.9 0.0 41.0 2005-2006 0.0 T 9.7 2.0 26.9 1.3 0.1 40.0 2006-2007 0.0 0.0 0.0 2.6 3.8 6.0 T 12.4 2007-2008 0.0 T 2.9 T 9.0 T 0.0 11.9 2008-2009 0.0 T 6.0 9.0 4.3 8.3 T 27.6 2009-2010 0.0 0.0 12.4 2.1 36.9 T 0.0 51.4 2010-2011 0.0 T 20.1 36.0 4.8 1.0 T 61.9 2011-2012 2.9 0.0 0.0 4.3 0.2 0.0 0.0 7.4 2012-2013 0.0 4.7 0.4 1.5 12.2 7.3 0.0 26.1 2013-2014 0.0 T 8.6 19.7 29.0 0.1 T 57.4 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 T T 4.8 2020-2021 0.0 0.0 10.5 2.1 26.0 T M 38.6

The 0z Euro was even more aggressive with the warming for Long Island with the WSW afternoon wind shift. Now has 70s away from the immediate South Shore beaches. That would result in steeper low level lapse rates and wind gust potential over 50 mph. We will have to watch for that sting jet-like feature behind the front.

The weak low that almost had subtropical characteristics will bring some much needed rains today. The models have elevated convection with locally heavy downpour potential. This tucked in low track looks similar to the tropical systems last summer that affected the area. More of the same on tap for this year? Stay tuned....

Friday could be the warmest day of the year so far. Euro has mid to upper 70s. Then 50 mph + wind gust potential with the cold front.

COOP sites are maintained much better than Central Park. Most recent photo in 2013...must be even more overgrown by now... Old photo before vegetation was overgrown

The low temperatures in NYC seem to be doing better that the highs during the summer. Notice how there has been a slight decline in average high temperatures since 1981. This reflects the overgrowth of trees and vegetation. White Plains and NYC have a similar rise in minimum temperatures. But you can see the highs increasing there since the sensor at the airport isn’t under a dense canopy. So while people rightly take issue with Central Park snowfall measurements, the error is far less than the temperature sensor getting overgrown by vegetation.

Yeah, the issue of trees blocking direct sunlight has had a much bigger impact on temperature accuracy. You can see the cooler maximum temperatures now when the trees are fully leafed out. UHI has been remarkably steady since 1900 in Central Park.

We are on track for our first 2 consecutive warmer than average Marches since 2011-2012. March was one of our few colder months of the year from 2013 to 2019. November has been the other cooler month but we had record warmth this year. NY Coastal Climate Division https://www.ncdc.noaa.gov/cag/divisional/time-series/3004/tavg/1/3/2010-2020?base_prd=true&begbaseyear=1981&endbaseyear=2010 202003 45.0°F 8 5.2°F 201903 38.8°F 5 -1.0°F 201803 38.8°F 6 -1.0°F 201703 37.7°F 3 -2.1°F 201603 45.8°F 10 6.0°F 201503 35.1°F 1 -4.7°F 201403 35.5°F 2 -4.3°F 201303 38.7°F 4 -1.1°F 201203 47.9°F 11 8.1°F 201103 40.8°F 7 1.0°F 201003 45.4°F 9 5.6°F

The Euro and CAMS have some elevated convection with this feature on Wednesday. But it’s hard to tell how widespread the coverage will be. Maybe we can get something.

The lack of clouds, rain, and humidity has been impressive around the region for March.

Another low dewpoint special today. Central Park SUNNY 62 13 14

This was the warmest winter at Newark that recorded 45”+ of snow. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Apr 30 DJF Avg Temp 1 1996-04-30 78.4 31.6° 2 1961-04-30 73.5 30.8° 3 2011-04-30 68.2 32.9° 4 1978-04-30 64.9 28.6° 5 1994-04-30 64.5 31.0° 6 2014-04-30 61.1 31.3° 7 1958-04-30 58.3 32.8° 8 1967-04-30 57.3 34.3° 9 2003-04-30 53.1 30.7° 10 1948-04-30 51.0 28.9° 11 2010-04-30 47.9 33.7° 12 2004-04-30 47.8 31.8° 13 2015-04-30 46.4 30.4° 14 2021-04-30 45.7 35.2°

Historic rainfall and flooding in March 2010. While our area had around 10”, SNE was 10-20”. https://www.weather.gov/media/box/science/March_2010_Floods.pdf

The latest Euro is warm and dry. Has more wind than rain with the cutter later in the week. So that could be our next chance of 70s. Only has a brief cool down near the end of the month.

The March low dewpoint and underperforming rainfall pattern continues. Newark Liberty SUNNY 60 13 15 W7 PRECIPITATION (IN) TODAY 0.00 1.75 1958 0.14 -0.14 T MONTH TO DATE 0.92 2.59 -1.67 2.24

Newark is on track for its earliest last measurable snowfall following a 45”+ season. So you can see how extreme that AO reversal was back in mid-February. With the exception of 14-15, our snowfall has been very AO dependent. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Apr 30 Last Measurable 1 1996-04-30 78.4 4-10 2 1961-04-30 73.5 3-31 3 2011-04-30 68.2 3-21 4 1978-04-30 64.9 3-16 5 1994-04-30 64.5 3-18 6 2014-04-30 61.1 4-16 7 1958-04-30 58.3 3-21 8 1967-04-30 57.3 3-22 9 2003-04-30 53.1 4-7 10 1948-04-30 51.0 3-11 11 2010-04-30 47.9 2-26 12 2004-04-30 47.8 3-19 13 2015-04-30 46.4 3-21 14 2021-04-30 45.7 2-22

Looks like Monday.

The most interesting part of our tropical activity last 10 years has been the impressive blocking to our north and east. The strong WAR in 2011 forced Irene to run just inland up through the Carolinas to our area. Then Sandy in 2012 met the record block to our north and made the historic left turn into New Jersey. Last summer Isaias made the tucked in track just inland due to the strong ridge east of New England. So the 500 mb blocking patterns have prevented a stronger hurricane landfall from Suffolk up into New England. This Suffolk to New England track was common from the 30s to the 50s. But it has been absent since Hurricane Bob in 1991.

The extreme drought conditions in the West should be a player in the summer forecast. Another factor will probably be the record warm pool east of New England. So maybe a dueling WAR and Rockies/ Plains ridge for the summer. Warmest winter SSTs on record east of New England

It matches the pattern since the snowfall increase in 02-03. Notice how the big February years had a snowy December and less snowy January and March. 13-14 was able to manage a snowy January but less snowy March. We pretty much knew the snowfall was going to come to quick stop following the record AO rise in mid-February. AO volatility has been a common feature for us in recent years. The 10-11 season cut off abruptly preventing us from catching 95-96 when the AO rapidly rose. 15-16 featured the epic AO reversal that gave us the +13 in December and 30” snowstorm in January. 17-18 featured another big AO swing which produced 80° in February and 30” of snow in March. 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 2009-2010 0.0 0.0 12.4 2.1 36.9 T 0.0 51.4 2013-2014 0.0 T 8.6 19.7 29.0 0.1 T 57.4 2005-2006 0.0 T 9.7 2.0 26.9 1.3 0.1 40.0 2002-2003 T T 11.0 4.7 26.1 3.5 4.0 49.3 2020-2021 0.0 0.0 10.5 2.1 26.0 T M 38.6

Hard to believe that Christmas was our last cutter with 1.00”+ of rain in NYC and 60°. The main storm track since then has been Miller Bs sliding by to our south. It will be interesting to see if the Euro is correct about an actual warm and wet cutter for next week.

This happens all the time during convection season. Model forecasts often don’t match the location of the best convection. You could see all the best convection going by just our south yesterday. THE ATLANTIC CITY NJ CLIMATE SUMMARY FOR MARCH 18 2021... PRECIPITATION (IN) YESTERDAY 1.73 1.76 1946 0.15 1.58 0.01

About .68 here is SW Suffolk. Less rain than forecast. Maybe the convection associated with the high risk to our south threw the models off.

March has had an inverse relationship to February snowfall since the snowier era began in 2003. All the 20”+ Februaries had under 4” during March in NYC. The under 5" Februaries generally had a nice rebound in March like in 2018. 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 2003 26.1 3.5 2021 26.0 T Monthly Total Snowfall for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Feb Mar 2020 T T 2012 0.2 0.0 2004 0.7 4.8 2019 2.6 10.4 2007 3.8 6.0 2016 4.0 0.9 2009 4.3 8.3 2011 4.8 1.0 2018 4.9 11.6

It looks like we are on track for a warmer than normal March. While the departures won’t be a s high as last year, it would be the 2nd warmer March in a row. This is a departure from previous years when March was a reliably colder month. We also saw record warmth in November which has also been a colder month recently.