bluewave

I believe this is our first two consecutive Julys with 10.00”+ at any of our major stations. Hard to know if this has happened before at the smaller PWS or coop sites. But the strong subtropical flavor continues with very wet and high dew point regimes of recent summers. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Jul Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 1889 11.89 0 2 1975 11.77 0 3 2021 10.48 4 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Jul Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 2020 11.22 0 2 1988 9.98 0 3 1984 8.65 0 4 2004 8.39 0 5 2021 8.30 4

Saturday looks like it will be the coolest morning.

The big story this summer is how we needed a record low pressure pattern to get back closer to the 2010s average following the near record finish last year.

Models hinting at a very cool ending to July. Be interesting to see if a spot like Newark can actually dip under 60°. The last time this happened on July 31st at Newark was 1956. KEWR GFSX MOS GUIDANCE 7/28/2021 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 WED 28| THU 29| FRI 30| SAT 31| SUN 01| MON 02| TUE 03| WED 04 CLIMO X/N 85| 69 78| 69 85| 59 82| 66 83| 65 82| 64 81| 67 85 67 86 Data for July 31 - NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 1932-07-31 83 56 T 0.0 M 1956-07-31 81 58 0.00 0.0 0 1936-07-31 79 58 0.00 0.0 0 1964-07-31 82 61 0.00 0.0 0

LGA gusting to 45 mph. 27 Jul 7:34 pm 83 58 43 NNW 25G45 10.00

All the July heat since 2010 has really raised the bar. Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Jul Season Mean 79.9 79.9 2021 79.1 79.1 2020 80.8 80.8 2019 80.6 80.6 2018 78.2 78.2 2017 77.3 77.3 2016 79.9 79.9 2015 79.0 79.0 2014 77.0 77.0 2013 80.9 80.9 2012 80.8 80.8 2011 82.7 82.7 2010 82.3 82.3 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Jul Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2011 82.7 0 2 1993 82.5 0 3 2010 82.3 0 4 1994 81.9 0 5 2013 80.9 0 6 2020 80.8 0 - 2012 80.8 0 - 1999 80.8 0 7 2019 80.6 0 8 1955 80.5 0 9 1988 80.4 0 10 2002 80.0 0 11 2016 79.9 0 12 1983 79.6 0 - 1966 79.6 0 13 1995 79.5 0 - 1949 79.5 0 14 2006 79.4 0 - 1987 79.4 0 15 1981 79.2 0 - 1952 79.2 0 16 2021 79.1 5 17 2015 79.0 0 18 1980 78.8 0 19 2008 78.7 0 20 1973 78.6 0 21 2005 78.3 0 - 1982 78.3 0 22 2018 78.2 0

This was one of the cooler Julys for a top 10 warmest June and July period. Monthly Mean Avg Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Jun Jul Season 1994 77.8 81.9 79.9 2010 76.2 82.3 79.3 1993 75.8 82.5 79.2 2011 74.5 82.7 78.6 2021 76.2 79.1 77.7 2020 74.4 80.8 77.6 1999 74.2 80.8 77.5 2013 73.3 80.9 77.1 2008 75.3 78.7 77.0 1987 74.4 79.4 76.9 1981 74.6 79.2 76.9

Only the 7th time that Newark reached 90°on 27 days by the end of July. It’s also the first time on the list since 1991 that there were so few 90°days in July. So the May and June heat allowed Newark to make it 5th place by the end of July. Monthly Number of Days Max Temperature >= 90 for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Apr May Jun Jul Season 2010 1 2 13 21 37 1993 0 3 9 22 34 1987 0 4 11 14 29 1994 1 1 10 16 28 2011 0 1 4 22 27 1991 0 8 10 9 27 2021 0 4 12 11 27

The unusually strong 500 mb anomaly over Canada allowed us to escape the major heat this July that has been common since 2010. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Jul Click column heading to sort ascending, click again to sort descending. Year Mean Avg Temperature Missing Count 2021 79.1 5 2020 80.8 0 2019 80.6 0 2018 78.2 0 2017 77.3 0 2016 79.9 0 2015 79.0 0 2014 77.0 0 2013 80.9 0 2012 80.8 0 2011 82.7 0 2010 82.3 0 Time Series Summary for LAGUARDIA AIRPORT, NY - Month of Jul Click column heading to sort ascending, click again to sort descending. Year Mean Avg Temperature Missing Count 2021 77.9 5 2020 82.9 0 2019 81.5 0 2018 79.8 0 2017 78.1 0 2016 81.1 0 2015 79.2 0 2014 77.0 0 2013 81.2 0 2012 80.4 0 2011 80.4 0 2010 82.8 0

So far this is the second most positive summer AO on record for the June into July period. 2016 wasn’t nearly as positive for this first half of summer interval. If the lower pressures were more aligned with the AO region, then it would be even more positive. That’s why the raw indices don’t always tell the complete story. It would be nice to have the daily AD anomaly to combine the two indices for a more complete picture. You can see the Arctic pressures were lowest in the series for the month of June just edging out 1970.

JFK was able to set its highest dew point record of 84° in 2016. But you can see how all the highest records were in recent years. The mid-July 1995 heatwave was impressive for several sites reaching the 100/80 mark.

This is actually the lowest Arctic pressures for the first half of summer since 1989. Looking at the raw indices like the AO doesn’t really do this pattern justice. While the core of the low pressure is closer to the Russian side this summer, the overall Arctic pressures haven’t been this low in the post 2007 era. In the much cooler late 80s with the healthier ice pack, we would be talking about a September daily minimum extent near 7 million sq km like 1989. But we’ll have to settle for whatever passes for good in the post 2007 Arctic this year.

That was 2018. JFK is currently at 7 days with a 75° or higher dew point . Only 3 more days needed for the first 6 year run. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=161&network=NY_ASOS&zstation=JFK&var=max_dwpf&dir=aoa&thres=75&month=all&year=2021&dpi=100&_fmt=js

Yeah, more record rainfall and flooding.

Another top 10 highest dew point July at JFK and ISP. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=76&network=NY_ASOS&station=JFK&season=jul&varname=dwpf&year=1893&w=bar&hours=0-23&dpi=100&_fmt=png

A combination of a warmer atmosphere holding more moisture and slower moving systems.

Another 2.31 on the North Shore with the thunderstorms last night. This brings the Port Washington total to 14.31 for July so far. This probably ranks among the heaviest July rainfall totals ever recorded on Long Island. NY-NS-27 Port Washington 0.8 N Lat: 40.839167 Lon: -73.68025 * indicates Multi-Day Accumulation Report Station NY-NS-27 Date Precip in. 07/01/2021 1.04 07/02/2021 1.12 07/03/2021 2.26 07/04/2021 0.79 07/05/2021 0.00 07/06/2021 0.00 07/07/2021 0.43 07/08/2021 0.01 07/09/2021 3.07 07/10/2021 2.06 07/11/2021 0.02 07/12/2021 0.21 07/13/2021 0.04 07/14/2021 0.02 07/15/2021 T 07/16/2021 0.00 07/17/2021 0.00 07/18/2021 0.28 07/19/2021 0.05 07/20/2021 0.01 07/21/2021 T 07/22/2021 0.34 07/23/2021 0.01 07/24/2021 0.00 07/25/2021 0.22 07/26/2021 2.33 Totals : 14.31 in.

Yeah, these rainfall extremes are occurring all across the world. This is officially the wettest monsoon on record to date in Tucson. Also notice how the intensity of the monsoon produced the record cool temperatures in Phoenix.

Yeah, looks like this will be the 6th month since 2010 that at least one of our major stations goes 10.00”+. August 2011 was the last time all our stations went 10.00” in the same month. It will be interesting to see if we can eventually get a 10.00” winter month in the coming years. The only one in NYC history was Jan 1979. But out of 10.59, only 6.6 fell as snow. I wonder what the highest precipitation total winter month we can get and still have most of it fall as snow? Philly picked up 5.75 in Feb 2010 and 51.5 of that was snow. NYC got 6.69 in Feb 2010 and 36.9 was snow. Be interesting to see the maximum snowfall we can get from a 10.00 winter month. Jul….2020….EWR…11.20 Aug..2014…..ISP……14.07 Jun..2013……NYC….10.10 Aug..2011……EWR….18.79…..other stations in same range Mar…2010…..NYC…..10.69

Flash flooding today in London.

Albany was a cool oasis in a sea of warm back in June. ALB….-0.2 POU…+2.8 BTV….+4.3 BGM..+3.4 SYR…+5.5

June was a top 1-5 warmest for the Northeast. But July only ranks In the top 20s for many spots. This is one of the biggest temperature ranking declines from June to July that we have ever seen.

This is one of the more impressive temperature gradients that we have seen this time of year. So an up and down temperature pattern. With all the quick changes, there will be something for everyone.

This is the first time in the post 2010 era that Newark experienced such a big monthly maximum temperature drop from June to July. Monthly Highest Max Temperature for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Year Jun Jul Season Mean 96 100 +4 2021 103 97 -6 2020 93 96 +3 2019 93 99 +6 2018 96 98 +2 2017 99 98 -1 2016 91 99 +8 2015 93 98 +5 2014 92 96 +4 2013 96 101 +5 2012 99 104 +5 2011 102 108 +6 2010 98 103 +5

With all the blocking, areas just N and W of NYC could see 50s next weekend.