bluewave

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.

The last 3 snowfall seasons had their most extreme snowfalls in the fall or spring. 17-18 featured the record breaking 30" of snow in March on Long Island. The 18-19 season had the best snows in November and March with very little for DJF. May 2020 tied with 1977 for the latest trace of snow following one the lowest seasonal snowfall totals. This season we finally got our most interesting snowfall records in February.

One last shot of winter into the weekend before spring tries to make a return next week.

Probably our last chance for some snow this season as spring tries to make a push next week.

Pretty impressive set of records for Cheyenne. NYC had its record all-time snowstorm in January 2016. October 2011 featured the biggest October snowstorm. So it’s quite a feat to pull this of in the same season. Upon further review, the 2-day snow observation of 30.8" fell 1.1" short of the 2 day record of 31.9" set in 1949. However, we did break the 1 day record for snowfall at Cheyenne with 22.7"

First NYC dewpoint below -10 this late in March in a while. Central Park SUNNY 29 -11 17 VRB5G23

6th March at Newark with a 50° or greater temperature drop within 4 days. 3-11-21....75°.....3-15-21.....24°........-51° 3-1-17......73°......3-5-17......14°........-59° 3-14-07....79°......3-16-07....25°........-54° 3-8-87......77°......3-10-87....16°........-61° 3-19-86....72°......3-21-86....16°........-56° 3-2-72......78°......3-4-72.......20°.......-58°