bluewave

We were as backloaded as Glasgow was frontloaded.

First time since 1950 that NYC had no measurable snowfall first week of March with such a low warmest minimum. 2014 was the only recent year that came close. It was also the last time NYC had more than 25” of snow in February. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Min Temperature Mar 1 to Mar 7 Snowfall 1 1960-03-07 21 14.8 2 1978-03-07 25 5.0 3 1950-03-07 30 T 4 2006-03-07 31 1.3 - 1969-03-07 31 5.6 5 2021-03-07 32 0.0 - 2014-03-07 32 0.1 - 1952-03-07 32 5.3 6 2019-03-07 33 10.4 Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Feb Click column heading to sort ascending, click again to sort descending. Year Total Snowfall Missing Count 2021 26.0 0 2020 T 0 2019 2.6 0 2018 4.9 0 2017 9.4 0 2016 4.0 0 2015 13.6 0 2014 29.0 0

More confirmation of the GFS cold bias fix.

The AO reversal in February continues to set records. This is the first February with a daily -5 reading and only a monthly -1 average. The previous -5 drops in 2010, 1978, and 1969 all had -3 and lower monthly averages. https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.ao.index.b500101.current.ascii https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/monthly.ao.index.b50.current.ascii.table 2021 -2.484 -1.191 2010 -2.587 -4.266 1978 -0.347 -3.014 1969 -2.967 -3.114

The lack of multi-year ice has finally allowed the 1st transit of the Northern Sea Route in February.

The more slowly warming spring temperatures relative to the other seasons is reflected in the new 1991-2020 climate normals.

The spring of 2010 was a real outlier. Spring is the slowest warming season for us since 1981. So our springs usually feature a back and forth between warm and cool. But the warmer temperatures still have won out. Just not as lopsided as the other seasons. https://www.ncdc.noaa.gov/cag/divisional/time-series/3004/tavg/3/5/1981-2021?trend=true&trend_base=10&begtrendyear=1981&endtrendyear=2020 Seasonal warming for our area since 1981 DJF.........+0.8° F per decade MAM......+0.4°F JJA........+0.7°F SON.......+0.8°F

Euro coming in even warmer now for next week. Has the first 60s of the year by next Tuesday. Then it has a chance for some of the warmer spots to reach 70° by later next week. Looks like the big AO rise will really amp up the SE Ridge for a while.

That 1995 event was near the start of high dewpoint era. Matches the steep increase in minimum temperatures. 110°+ heat indices have occurred in 1993,1995, 1999, 2010, 2011, and 2019.

Yeah, the minimums are rising quickly at both urban and rural sites. POU has fewer July lows in the 40s. While the NYC lows in the 50s have been harder to come by.

The NYC years since the 1990s would be much warmer than the 1950s to 1980s if the sensor wasn’t blocked by the thick vegetation. The warmest 30 day periods at EWR and LGA were in more recent times. So we can add a few degrees to the more recent NYC warmest 30 day periods. warmest 30 day periods LGA 83.8...2010 83.3...2020 82.9....2005 82.8....2016 82.7....2006 82.5....2013 82.4....1999 81.9....1995 81.7....2019 81.8....1966 81.6....2012 81.5....1980....1955 EWR 83.6....1993 83.4....2011 83.1....1988 82.9....2010 82.6....2013 82.2....1994 82.0.....2005 81.9.....1999 81.6.....2012 81.4.....1980 81.3.....2016 81.2.....2020 81.1.....1955 80.6.....1966...1979 80.5.....1973

Yeah, the two most memorable heatwaves of the 1970s were late August into early September 1973 and mid-July 1977. The brief heatwave around 7-4-74 was also memorable since is was in the mid 90s for the July 4th celebrations. The 70s heatwaves usually didn’t last too long. Even the famous 1977 heatwave dropped into the 50s a few days later. NYC when the sensor was in the shade under thick foliage 1977-07-13 93 73 83.0 6.4 0 18 0.00 0.0 0 1977-07-14 92 73 82.5 5.8 0 18 0.00 0.0 0 1977-07-15 96 72 84.0 7.3 0 19 0.00 0.0 0 1977-07-16 98 75 86.5 9.8 0 22 T 0.0 0 1977-07-17 97 78 87.5 10.7 0 23 T 0.0 0 1977-07-18 100 78 89.0 12.2 0 24 0.00 0.0 0 1977-07-19 102 78 90.0 13.2 0 25 0.00 0.0 0 1977-07-20 92 75 83.5 6.7 0 19 0.06 0.0 0 1977-07-21 104 78 91.0 14.2 0 26 0.00 0.0 0 1977-07-22 88 68 78.0 1.2 0 13 0.00 0.0 0 1977-07-23 87 62 74.5 -2.3 0 10 0.00 0.0 0 1977-07-24 90 70 80.0 3.2 0 15 0.00 0.0 0 1977-07-25 78 70 74.0 -2.8 0 9 0.48 0.0 0 1977-07-26 82 62 72.0 -4.7 0 7 0.00 0.0 0 1977-07-27 81 58 69.5 -7.2 0 5 0.00 0.0 0

Looks like the new GFS upgrade will be on March 17th. It seems to have fixed the cold and suppressed bias. It did much better than the v15 with the December snowstorm. https://www.weather.gov/media/notification/pdf2/scn21-20gfs_v16.0.pdf Subject: Upgrade of NCEP Global Forecast Systems (GFS) to v16 Effective March 17, 2021 Effective on or about March 17, 2021, beginning with the 1200 Coordinated Universal Time (UTC) run, the National Centers for Environmental Prediction (NCEP) will upgrade the GFS and Global Data Assimilation System (GDAS) from version 15.3 to 16.0. NCEP also will roll in the operational standalone https://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/

With a NYC average of temperature of 75.0°, it wasn’t really a hot summer by recent standards. But it was the only July in NYC during the 1970s with 3 days reaching 100°. The sensor was in the open sunlight back then. 100° is a struggle now since all the foliage growing over the site keeps it cooler. Newark only had 2 days reach 100° with no 100s at LGA and JFK.