bluewave

This cool pattern since early April really dropped the SST departures to our east. Unusual to see them colder than normal for a change.

It probably is a piece of the puzzle some years. But we were wet during the summer in 2018 with that record WAR. 2017 was a little cooler than average with higher dew points. But a dry summer in the rainfall department. A good chunk of the summer rainfall in 2014 was with that 1000 year deluge over just a few hours. And we can’t forget the record breaking rainfall during the summer of 2011.

Even with the record high dew points since 2016, the only wetter summer than average at Islip was 2018. The lower dew point summers from 2010 to 2014 were wetter. Go figure... JJA average rainfall 11.68” Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Jun through Aug Click column heading to sort ascending, click again to sort descending. Year Total Precipitation Missing Count 2019 10.64 0 2018 12.94 0 2017 9.41 0 2016 5.25 0 2015 7.27 0 2014 18.82 0 2013 13.21 0 2012 18.54 0 2011 17.02 0 2010 7.67 0

Euro maintains the easterly flow for at least the next week. So coastal sections will continue to be the coolest part of region. Friday into Saturday will probably the only days with some actual rain.

Record rainfall continuing over the Great Lakes. https://weather.com/storms/severe/news/2020-05-05-great-lakes-record-levels-april

Looks like Newark has a shot at top 10 driest May unless we get a heavy rain event near the end of the month. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of May Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 1964 0.52 0 2 1939 0.78 0 3 2020 0.81 13 4 1941 0.98 0 5 1935 1.01 0 6 2005 1.21 0 7 1965 1.23 0 8 1977 1.31 0 9 1986 1.41 0 10 1962 1.46 0

That 1962-1966 drought was the most intense since the 1600’s. The 1966 record heat was at the end of that historic dry period. Our climate has become much wetter and humid since then. https://seaandskyny.com/2012/04/29/trees-tell-the-story-of-500-years-of-nyc-drought-history/

Newark has only reached 70 degrees or higher on 9 days since March 1st. This is the 4 lowest number of days on record through May 18th. Big reversal from years like 2010, 2012, and 2015. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Max Temperature >= 70 Mar 1 to May 18 Missing Count 1 1966-05-18 4 0 2 1978-05-18 7 0 3 1967-05-18 8 0 4 2020-05-18 9 0 - 1997-05-18 9 0 5 1968-05-18 10 0 - 1940-05-18 10 0 Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Number of Days Max Temperature >= 70 Mar 1 to May 18 Missing Count 1 2012-05-18 29 0 - 2010-05-18 29 0 2 1985-05-18 28 0 - 1977-05-18 28 0 3 1945-05-18 26 0 4 1981-05-18 24 0 - 1976-05-18 24 0 5 2015-05-18 23 0

A great push of spring migrants finally arrived with the warm front late last week. It took a while to get a favorable SW flow for migration.

Probably a better chance of needing the heat than AC next several days. Coastal sections could see 30 to 40 mph easterly gusts on Tuesday. Interior sections should drop into the 30’s early on Thursday.

The continuing IO standing wave may mean that this doesn’t follow the typical developing La Niña playbook. We currently have record SST’s in the Indian Ocean. Typical La Niña summer forcing pattern closer to Maritime Continent Seasonal forecast further West IO forcing

The Euro has plenty on easterly flow over the next 10 days. The warmest that the Euro gets through the 27th is 75-80 in the warmer locations of NJ. This Is well below average for a max from the 17th to the 27th. Many years we make it to 90 degrees or higher in at a place like Newark. The last time Newark didn’t reach 80 was back in 2003. That was also the most recent time that we had below average temperatures in both April and May. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Ending Date Highest Max Temperature May 17 to May 27 Missing Count 2019-05-27 90 0 2018-05-27 92 0 2017-05-27 94 0 2016-05-27 93 0 2015-05-27 91 0 2014-05-27 88 0 2013-05-27 88 0 2012-05-27 86 0 2011-05-27 88 0 2010-05-27 95 0 2009-05-27 87 0 2008-05-27 87 0 2007-05-27 92 0 2006-05-27 86 0 2005-05-27 84 0 2004-05-27 92 0 2003-05-27 78 0

The ocean is still in the low 50’s. Jones Beach N/A 52 N/A N/A SE13 N/A Wantagh N/A 57 48 72 SE13 N/A NY Harb Entrance 1750 51 54 100/ 12/ 14 1025.3 3/ 4 20 S Fire Island 1750 51 53 90/ 12/ 14 1025.3 3/

Tough to get much rain as long as that blocking high remains anchored near New England. Strong blocking in various locations has been the big story since April. As we can see below, models have been underestimating the blocking intensity beyond 5 days out. That’s why I won’t really believe a shift to warmer until it verifies under 120 hrs. The spring long range model warm up forecasts are the equivalent of the big snow was always 10 days away during the winter. New run Old run

We are on track for no 90 degree days this year right through Memorial Day. EPS keeps a UL over the East with strong high pressure east of New England. So it maintains a cooler easterly flow. It does briefly turn the winds SW later this week for a chance to make 80 degrees on Friday. But it looks like the 86 at Newark on the 15th will hold as the monthly high temperature for a while.

12z Euro is dry through 120 hrs with the tropical system remaining offshore.

This was 0z.

The Euro does much better with tropical and trough interactions than the GFS. I would believe it if the 12z Euro came in more phased than the 0z run. But the 12z GFS took a step further east. The 12zCMC, UKMET, and NAM are similar to the 0z Euro more OTS.

The GFS tried to do the same with Joaquin while the Euro was OTS. You can see the 12z beginning to shift toward the other models. https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/10/06/what-the-european-model-win-over-the-american-model-means-for-weather-forecasting/

We know that the summer dew points increased to record levels since the super El Niño in 2016. But it will be interesting to see how those seasonal model forecasts work out for this summer. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=yes&q=161&network=NY_ASOS&zstation=AMW&var=max_dwpf&dir=aoa&thres=65&month=all&year=2020&dpi=100&_fmt=js

Euro and UKMET pretty much identical to the CanSIPS and JMA for the summer. Strongest heat over the Western US with wet and humid conditions in the East. Also notice the heavy precipitation with the IO standing wave.

There could be a very sharp cutoff between who gets the heaviest rains and doesn’t.

We get our brief warm up followed by about a week of easterly flow. Rainfall amounts will probably be determined in the short term. Looks like models are struggling with the placement of a PRE. Often happens with a subtropical or tropical systems to our SE.

We had 2 recent winters with the La Niña background state and an El Niño that couldn’t really develop. The MJO remained in the unfavorable phases. Models are hinting at a -IOD for next winter. This would mean more warm SST’s north of Australia near the Maritime Continent. So unfavorable MJO phases could be a player again. But the coupled La Niña in 16-17 and 17-18 had to deal with this . We were able to sneak in snowy intervals during those winters which alternated with record warmth. The last few winters the snowy intervals never materialized. So it will be interesting to see if a more coupled La Niña next winter resembles 16-17 and 17-18. Or has more in common with 18-19 and 19-20.

The CanSIPS has the same summer pattern. The IO has had a big influence on our weather since the record +IOD last fall.