bluewave

Finally getting some more spring-like 70’s this weekend. Models hinting at the first May 30’s in NYC since the 1970’s next weekend. This would mean an unusually late freeze for some outlying areas if it verifies. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of May Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 1977 36 0 2 1978 38 0 - 1976 38 0 - 1970 38 0

Our recent long streaks were 16 days in November 2018 and 22 days in March 2018.

16th day in a row with a negative temperature departure in NYC. This is a rare feat after April 15th. Most of our streaks this long have occurred from November into March. 2020-04-15 -4.9 2020-04-16 -9.3 2020-04-17 -10.1 2020-04-18 -10.5 2020-04-19 -2.8 2020-04-20 -2.2 2020-04-21 -5.0 2020-04-22 -11.8 2020-04-23 -9.6 2020-04-24 -10.5 2020-04-25 -1.8 2020-04-26 -10.1 2020-04-27 -12.4 2020-04-28 -3.2 2020-04-29 -4.5 2020-04-30 -3.0

Sun is out now on Long Island. Looks like the heaviest rains will move through tonight.

This was the first April that Newark didn’t reach 70 degrees.It was also the 3rd lowest monthly max for NYC. First time that Islip stayed below 65 degrees in April. Also the first year that both January and March had a warmer monthly maximum temperature than April. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 69 1 2 1940 70 0 3 1931 71 0 Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 1874 64 0 - 1873 64 0 2 1940 67 0 - 1875 67 0 3 2020 68 1 - 1883 68 0 4 1884 69 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 64 1 2 1988 68 0 - 1975 68 0 3 2014 69 0 - 1998 69 0 - 1984 69 0 - 1980 69 0 - 1978 69 0 Monthly Highest Max Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Jan Feb Mar Apr Season 2020 70 62 80 69 80 Monthly Highest Max Temperature for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Jan Feb Mar Apr Season 2020 69 62 77 68 77

No surprise that this was one of the cloudiest Aprils on Long Island around noontime. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=45&network=NY_ASOS&zstation=ISP&hour=12&year=2020&month=4&dpi=100&_fmt=png

Right back to our default -EPO pattern since 2013. Just goes to show how unusual the strong winter +EPO was for this era. Occasionally the -EPO becomes strong enough to flatten out the SE Ridge. This is when we get the odd cold departure month. This EPO reversal returned the PDO back to positive territory after a dip negative.

All the summers since the super El Niño in 2016 had near to record high dew points. The only summer with slightly cooler departures in the 0 to -0.5 range was 2017. The 2016 summer was a top 10 warmest across the area. Numerous top 10 warmest Julys and Augusts during 2016, 2018, and 2019. Time Series Summary for LAGUARDIA AIRPORT, NY - Month of Jul Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2010 82.8 0 2 1999 81.9 0 3 2019 81.5 0 4 2013 81.2 0 5 2016 81.1 0 6 1955 80.9 0 7 1966 80.8 0 8 2006 80.7 0 9 1994 80.6 0 10 2012 80.4 0 Time Series Summary for LAGUARDIA AIRPORT, NY - Month of Aug Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2016 81.6 0 2 2018 81.0 0 3 2005 80.9 0 4 2001 79.8 0 5 2015 79.3 0 6 1995 79.1 0 7 1988 78.8 0 8 2012 78.7 0 - 1955 78.7 0 9 2010 78.6 0 10 2002 78.5 0

3rd highest number of days with measurable precipitation through the 26th in NYC. But the actual amounts were slightly below normal for the month so far. NYC...3.77....-0.17 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Precipitation >= .01 Apr 1 to Apr 26 Missing Count 1 1934-04-26 15 0 2 2019-04-26 14 0 - 1957-04-26 14 0 - 1936-04-26 14 0 - 1929-04-26 14 0 - 1874-04-26 14 0 3 2020-04-26 13 0

Maybe we can sneak in some 70’s from Friday into the weekend. But it looks like another cool down in about a week to 10 days.

You need at least 30-40 years to generate a meaningful trend with the NCDC charts. 10 years is too short a period of time to use on the site. You can generate charts for a wide variety of regions or cites. https://www.ncdc.noaa.gov/cag/divisional/time-series/3004/tavg/3/5/1981-2019?trend=true&trend_base=10&begtrendyear=1981&endtrendyear=2019

Spring has warmed less than all other seasons across our area since 1981. Local seasonal warming since 1981 DJF.......+0.7°F Decade MAM.....+0.4°F/Decade JJA........+0.6°F/Decade SON.......+0.8°F/Decade

EPS pretty bullish on maintaining the MJO 1-2 standing wave until further notice. This has translated into the blocking and Eastern Trough during April. It may be a result of the lingering record +IOD SST warmth from last fall. The rapid rebound to record SST’s north of Australia had a big influence on our winter pattern. So it will be interesting to see if events originating in the IO last fall can still have some effect on our summer regime.

This is probably the most significant monthly low max across the area since February 2015. We just don’t have the big -10 departure and top 2 monthly coldest finish. Since these cold records are few and far between, they really stand out. All the record warm records tend to run together and people get used to them. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Feb Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 1978 40 0 2 2015 42 0 3 1969 43 0 - 1934 43 0 4 1986 49 0 - 1968 49 0 - 1936 49 0 Time Series Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT - Month of Feb Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 1978 36 0 2 2015 37 0 3 1969 42 0 4 1963 43 0 5 1968 44 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Feb Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 1934 18.6 0 2 2015 22.6 0 3 1979 23.5 0 4 1936 24.4 0 5 1978 25.5 0

Some of the lowest April maximum temperatures on record across the region this month. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 69 5 2 1940 70 0 3 1931 71 0 Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 1874 64 0 - 1873 64 0 2 1940 67 0 - 1875 67 0 3 2020 68 5 - 1883 68 0 Time Series Summary for LAGUARDIA AIRPORT, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 1940 67 0 2 2020 69 5 - 1988 69 0 - 1980 69 0 Time Series Summary for JFK INTERNATIONAL AIRPORT, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 66 5 2 1998 67 0 3 2014 69 0 Time Series Summary for WESTCHESTER CO AP, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 64 5 2 1971 67 0 3 1975 68 0 Time Series Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 66 5 - 1998 66 0 - 1980 66 0 - 1950 66 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 64 5 2 1988 68 0 - 1975 68 0 Time Series Summary for New Brunswick Area, NJ (ThreadEx) - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 70 6 - 1916 70 0 3 1966 71 0 Time Series Summary for PHILADELPHIA INTL AP, PA - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 1975 73 0 2 1988 74 0 3 2020 75 5 - 1997 75 0 - 1984 75 0 Time Series Summary for POUGHKEEPSIE AIRPORT, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1 2020 68 5 2 1975 69 0 3 1988 71 0 - 1966 71 0 - 1961 71 0

This is the coolest April average and maximum temperature in NYC following a 40+ Dec-Mar. The only other April with close to a similar monthly max was 1998. That was also the coolest summer out of the group. Be interesting to see if we avoid the big heat of most other summers that followed such warm DJFM periods. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Dec 1 to Mar 31 April Avg and Max 1 2012-03-31 43.1 54.8 88 2 2016-03-31 43.0 53.3 82 3 2002-03-31 42.2 56.1 96 4 2020-03-31 41.4 50.1 68 5 1998-03-31 41.1 54.0 73 6 1991-03-31 40.5 55.7 90 Newark number of 90 degree days 2016...40.....5th highest 2012...33.....11th highest 2002...41.....4th highest 1998...21 1991...41.....4th highest

This would be a first. Monthly Highest Max Temperature for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Jan Feb Mar Apr Season 2020 69 62 77 68 77 Monthly Highest Max Temperature for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Jan Feb Mar Apr Season 2020 68 54 70 64 70 Monthly Highest Max Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Jan Feb Mar Apr Season 2020 70 62 80 69 80

Yeah, that record has been tough to beat. Numerous low 40’s for the May monthly minimum temperature. With all the rain in the forecast, the cooler maximums will probably be more impressive for NYC than the minimums. TEMPERATURE (F) YESTERDAY MAXIMUM 52 341 PM 86 2007 64 -12 77 MINIMUM 40 820 AM 29 1872 47 -7 56 AVERAGE 46 56 -10 67

Models continuing with the Eastern Trough right into May. April so far Forecast

Had a light mix of sleet and snow here in SW Suffolk this morning.

Yeah, the record Gulf SST’s helped fuel all the severe weather this month. The strong -EPO blocking near Alaska and -NAO allowed a piece of the TPV to drop into New England today. Notice how that block near Alaska pushed further east from the March position. Just a slight shift in concert with the -NAO flattened out the SE Ridge and delivered the cold. March April

Record low 850mb temperatures this morning.

The EPO reversal since the winter has been very impressive. The vortex cooled the NP SST’s over the winter. Now the warm blob south of Alaska is making another appearance with the strong ridge. There is also a sharp Atlantic SST gradient with cold to the north and warm south.

NYC is on track for only the 8th time not reaching 70 degrees in April. Pretty impressive that most of the other years were in the 1870’s and 1880’s. Just goes to show how strong this -EPO/-NAO pattern has been. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Rank Year Highest Max Temperature Missing Count 1874 64 0 1873 64 0 1940 67 0 1875 67 0 2020 68 9 1883 68 0 1884 69 0 1876 69 0

The maximum July temperature departure at Newark was +3.5 vs +3.0 for the minimum. JFK came close to their all-time record heat index late in July with the record heat and humidity. There were numerous record highs on July 20th and 21st.