bluewave

Weather stations in parks or more rural areas are fine. But the sensors must be in a clearing so they are not blocked by trees. The big error was moving the thermometer in NYC from an open area of the park to under a canopy.

September is quickly becoming our 4th month of summer. Notice how the last 8 out of 9 September’s at LGA averaged at 70 degrees or higher. Big jump since the 1980’s. Several recent Septembers were as warm or warmer than June. Monthly Mean Avg Temperature for LA GUARDIA AP, NY Click column heading to sort ascending, click again to sort descending. Year Jun Jul Aug Sep Season Mean 73.2 80.0 77.9 71.6 75.8 2010 76.0 82.8 78.6 72.5 77.5 2011 72.7 80.4 76.0 70.7 75.0 2012 72.9 80.4 78.7 70.7 75.7 2013 74.0 81.2 75.8 68.1 74.8 2014 72.5 77.0 75.1 70.4 73.8 2015 71.3 79.2 79.3 74.1 76.0 2016 73.6 81.1 81.6 73.8 77.5 2017 73.6 78.1 75.4 71.5 74.7 2018 72.9 79.8 81.0 72.8 76.6 2019 72.8 80.2 M M 76.5 Monthly Mean Avg Temperature for LA GUARDIA AP, NY Click column heading to sort ascending, click again to sort descending. Year Jun Jul Aug Sep Season Mean 71.4 77.0 75.6 68.4 73.1 1980 70.1 78.6 78.1 70.4 74.3 1981 72.6 78.1 75.7 66.4 73.2 1982 66.8 76.3 72.3 66.9 70.6 1983 72.5 78.3 76.7 70.6 74.5 1984 73.6 73.5 76.2 65.6 72.2 1985 68.8 76.6 75.7 70.7 72.9 1986 71.4 76.1 73.4 67.9 72.2 1987 72.9 77.6 74.0 68.1 73.2 1988 72.0 78.6 78.8 67.8 74.3 1989 72.9 76.1 75.3 69.7 73.5

5th consecutive NSIDC daily extent drop of 100k or greater. 2019 continues in first place on July 10th ahead of 2012. One of the most impressive weekly drops during the month of July. 7-10-19....7.996 7-10-12....8.130

This map says it all. https://mobile.twitter.com/Climatologist49/status/1126293596909367301

2nd year in a row with a dry start to July. Last year ended with a deluge. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Precipitation Jul 1 to Jul 9 Missing Count 2019-07-09 0.06 0 2018-07-09 0.24 0

Long term you are correct. But it has been very dry here last few weeks. Non-watered areas already turning brown on Long Island.

Hopefully, the front and the tropical moisture feed down to developing Barry can deliver some much needed rainfall.

I am hoping that the Euro is correct about the heavy rain potential Thursday night. We can really use the rain. Almost looks like a wannabe PRE with the tropical development in the Gulf. Not sure if the features are close enough to technically be called a PRE. But any rain after the dry last few weeks would be welcome.

2019 jumps into the extent lead over 2012 with a major 247k drop as of July 9th. 2019....8.098 2012....8.174

Warmer atmosphere holds more moisture. It will be interesting to see if the tropical remnants get surrounded by +20C 850 temperatures.

The warmer temperatures showing up in all the extended guidance will only reinforce the 80-90% above normal July temperature streak for the 2010’s. The departure increase from June into July has been a common feature. July......EWR....NYC...LGA 2018....+0.8....+1.1.....+2.4 2017....-0.1.....+0.3.....+0.7 2016...+2.5.....+2.2.....+3.7 2015...+1.6.....+2.3.....+1.8 2014....-0.4.....-0.4.......-0.4 2013....+3.5...+3.3......+3.8 2012....+3.4...+2.3......+3.0 2011....+5.3...+3.7......+3.0 2010...+4.9....+4.8......+5.4

The blocking and high pressure relaxation is coming just as 2019 edges ahead of 2012 for extent. But the thing that separated 2012 from the rest of the pack was the big storm and record late season decline. 2019...8.345 2012...8.398

The Central Park data is flawed due to the sensor being blocked by trees and foliage from sunlight and open airflow. Not because it’s located in a park. The open areas of the park are probably 1-3 degrees warmer for highs than the sensor area that is blocked. The old sensor was in an open area before 1996 with no obstructions. This is why NYC has an artificial 90 degree day cooling trend with more 90 degree days in 1991 and 1993 than 2010. Place sensors at a horizontal distance of 2 times the height of the nearest object (tree, structure, etc). [Example: 40 feet away from a 20 foot tall tree].

The warmer minimums were more impressive than the cooler maximums for the first week of July. The minimum temperature departures are in the lead again. Newark...max....+2.4....min....+4.3.....avg.....+3.4 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Min Temperature Jul 1 to Jul 7 Missing Count 2010-07-07 81 0 2019-07-07 77 0 2018-07-07 77 0 2016-07-07 77 0 2013-07-07 77 0 2012-07-07 77 0 2015-07-07 74 0 2014-07-07 73 0 2011-07-07 73 0 2017-07-07 71 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Jul 1 to Jul 7 Missing Count 2010-07-07 103 0 2012-07-07 102 0 2018-07-07 98 0 2011-07-07 97 0 2014-07-07 96 0 2013-07-07 96 0 2016-07-07 95 0 2019-07-07 92 0 2015-07-07 91 0 2017-07-07 90 0

This was the driest first week of July since 2010 in NYC. It’s odd since it was cooler with much higher humidity that the first week of July in 2010. Overall, it was the 4th lowest rainfall amount on record. Other stations like ISP had similarly dry conditions. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation Jul 1 to Jul 7 Missing Count 1 2010-07-07 0.00 0 - 2002-07-07 0.00 0 - 1962-07-07 0.00 0 - 1924-07-07 0.00 0 - 1912-07-07 0.00 0 - 1886-07-07 0.00 0 - 1878-07-07 0.00 0 - 1876-07-07 0.00 0 2 1994-07-07 T 0 - 1988-07-07 T 0 - 1966-07-07 T 0 - 1964-07-07 T 0 - 1959-07-07 T 0 - 1935-07-07 T 0 3 1938-07-07 0.01 0 4 2019-07-07 0.02 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation Jul 1 to Jul 7 Missing Count 1 2010-07-07 0.00 0 - 2002-07-07 0.00 0 - 1975-07-07 0.00 0 2 2019-07-07 T 0 - 1994-07-07 T 0 - 1977-07-07 T 0 - 1966-07-07 T 0

Yesterday was the 5th day since 2016 that the dewpoint reached 79 degrees or higher at JFK. Before 2016, there were only 3 days in total with a dewpoint this high. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=161&network=NY_ASOS&zstation=JFK&var=max_dwpf&dir=aoa&thres=79&month=all&year=2019&dpi=100&_fmt=js

3.00 inch hail on 8-1-11. https://mesonet.agron.iastate.edu/wx/afos/p.php?pil=LSROKX&e=201108022246

Tie for lowest maximum temperature YTD of 93 at Newark in the last 30 years. So we continue to see the minimum temperature departures outpace the maximums. Newark July departure through the 6th Max T....+2.6 Min T.....+4.6 Avg ......+3.6 June Max T.....-0.2 Min T.....+0.8 Avg.......+0.3 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Highest Max Temperature Mar 1 to Jul 7 Missing Count 1 2019-07-07 93 1 - 2015-07-07 93 0 - 2009-07-07 93 0 2 1998-07-07 94 0 3 2006-07-07 95 0 - 2003-07-07 95 0 - 2001-07-07 95 0

https://mobile.twitter.com/Maxar_Weather/status/1147124424656732162 Here is a look at the peak high thus far this year--Anchorage, Alaska managed to hit 90° before some locations in the Great Lakes region, Northeast, and Mountain West.

First storms of the day popping now. The heaviest one looks close to the GW bridge.

This looks more like a Florida convective cloud streets pattern. Dewpoints in the 75-80 degree range will do it.

Highest dewpoint of the year now with JFK at 78 degrees.

It’s a good thing the low cloud deck marine layer in LB held off until after the 4th. It also looks like the dredging and beach extension created a very long sandbar. http://www.lbsurf.org/surf-camera-report/

4th 75 degree dewpoint day of the year for JFK. Only 6 more needed for the first 4 consecutive years streak in the double digits. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=161&network=NY_ASOS&zstation=JFK&var=max_tmpf&dir=aoa&thres=90&month=jul&year=2019&dpi=100&_fmt=js

It will be interesting to see if 2019 can hold the area lead over 2012 if the models are correct about the polar blocking weakening. https://sites.google.com/site/cryospherecomputing/daily-data https://mobile.twitter.com/judah47/status/1147128282225287170