bluewave

August finishes with less warmth than last year. 7 out of the last 10 warmer than normal at EWR and NYC 6 out of the last 10 warmer than normal at LGA August....EWR....NYC....LGA 2019......+0.4.....+0.3.....+1.3. 2018.......+3.4.....+2.9.....+4.7 2017.......-1.8.......-1.2......-0.9 2016......+4.1......+4.0......+5.3 2015......+2.9.....+3.8.......+3.0 2014......-1.3......-0.7........-1.2 2013.....-1.1.......-0.6........-0.5 2012.....+1.8.....+1.5........+2.4 2011.....+1.1.....+0.1........-0.3 2010....+1.9......+2.2.......+2.3

It really is a very extreme pattern. We’ll just have to wait and see how things progress going forward.

It wasn’t able to figure out the more Niña-like pattern ahead of time. So the more Niño looking seasonal forecast didn’t work out. https://www.climate.gov/news-features/blogs/enso/csi-enso-case-missing-central-pacific-rainfall

2019 moves into 7th place on NSIDC extent at 4.589 million sq km as the extreme reverse dipole relaxes. Just a bit above the 2007-2018 average daily minimum extent of 4.510. 3.387....2012-9-17 4.155....2007-9-18 4.165....2016-9-10 4.344....2011-9-11 4.433....2015-9-9 4.586....2018-9-23 4.589....2019 4.615....2010-9-21 4.656....2018-9-23 4.665....2017-9-13

The Euro seasonal from back in March did a nice job with the summer forecast. Warmth along the coasts with cooler in the middle. Really nailed the record heat signal for Alaska.

This August is another example of less warm is the new cool. Relatively low number of August 90 degree days for the 2010’s this month. JFK hasn’t reached 90 degrees since July 21st. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Aug Click column heading to sort ascending, click again to sort descending. Year Number of Days Max Temperature >= 90 Missing Count 2019 4 1 2018 14 0 2017 2 0 2016 13 0 2015 13 0 2014 2 0 2013 3 0 2012 7 0 2011 4 0 2010 11 0 Time Series Summary for LA GUARDIA AP, NY - Month of Aug Click column heading to sort ascending, click again to sort descending. Year Number of Days Max Temperature >= 90 Missing Count 2019 5 1 2018 16 0 2017 2 0 2016 10 0 2015 8 0 2014 1 0 2013 1 0 2012 6 0 2011 2 0 2010 11 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Aug Click column heading to sort ascending, click again to sort descending. Year Number of Days Max Temperature >= 90 Missing Count 2019 1 1 2018 5 0 2017 0 0 2016 7 0 2015 2 0 2014 0 0 2013 0 0 2012 0 0 2011 2 0 2010 4 0 Time Series Summary for JFK INTL AP, NY - Month of Aug Click column heading to sort ascending, click again to sort descending. Year Number of Days Max Temperature >= 90 Missing Count 2019 0 1 2018 4 0 2017 0 0 2016 6 0 2015 6 0 2014 0 0 2013 0 0 2012 2 0 2011 2 0 2010 8 0

The dipole reversal around August 20th was one for the record books. We are not that far from the 2007-2018 NSIDC annual average daily minimum extent of 4.51 million sq km.The average minimum extent before 2007 was 6.18 million sq km from 1994 to 2005. Arctic amplification really took off once minimums began to regularly fall below 6 million sq km.

It will be interesting to see if the pattern producing the record SST’s in the Northeast Pacific can linger into winter like 13-14 to 15-16. This regime has been associated with the recent string of Canadian highs moving eastward off the New England Coast. Models continue this parade of big highs right into early September. https://mobile.twitter.com/WorldClimateSvc/status/1167071076934967296 As of yesterday, northeast Pacific area-average SSTs are more than 2°C above normal, according to @NOAANCEIclimate OISSTv2 daily data. This is well above the peak warmth of the "warm blob" years (2013-2016). It's been a remarkable run up since May.

While average summer dewpoints have been on the rise across the whole region, the highest local readings were found near the NYC and Long Island South Shore. The maps for July show this very well. Notice the overall higher dewpoint surge north up along the East Coast. We have been getting dewpoint readings more typical for the Mid-Atlantic region. Follows the theme of a shift to a more subtropical climate zone.

Another year with a very high number of 75 degree dewpoint days along the South Shore sections of NYC and Long Island. This was a 2nd top 3 finish in 2 years for JFK and ISP. The record breaking streak since 2016 continues. 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=2019&dpi=100&_fmt=js JFK 75 degree or higher dewpoint days #1....43...2018 #2... 25...2019 #3....24...1983 #4....19....2016 #5....18....1999 #6....17....2017....1995 ISP #1...34...2018 #2...19...2005 #3...18...2019 #4...15...1979...1975 #5....14...1998...1995 #6....13...2016....2002

Staying below 80 for 6 days in a row during August is pretty impressive. Only the 6th time this happened at Newark since 1948. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=42&network=NJ_ASOS&zstation=EWR&m=aug&yrange=1928-2019&dir=below&var=tmpf&threshold=80&hours=144&dpi=100&_fmt=png

We can see why the 0z Euro made the big jump west with the heavy rain. Wantagh already has .99 and climbing.

Yeah, these wild swings in the NAM have increased in amplitude as the climate has warmed. While the long term sea ice trend is down, it will probably be an up and down bumpy ride along the way.That’s why calling the exact date for the eventual ice free state will continue to be tricky. Maybe the best we can do is just say some time between 2030 and 2050. https://www.eurekalert.org/pub_releases/2009-01/whoi-sls011309.php PUBLIC RELEASE: 13-JAN-2009 Study links swings in North Atlantic oscillation variability to climate warming WOODS HOLE OCEANOGRAPHIC INSTITUTION SHARE PRINT E-MAIL Using a 218-year-long temperature record from a Bermuda brain coral, researchers at the Woods Hole Oceanographic Institution (WHOI) have created the first marine-based reconstruction showing the long-term behavior of one of the most important drivers of climate fluctuations in the North Atlantic. The North Atlantic Oscillation (NAO) is a wide-ranging pressure seesaw that drives winter climate over much of North America, Europe and North Africa. Past reconstructions of the NAO have relied mainly on terrestrial, or land-based records, such as tree ring chronologies combined with ice cores and historical climate data. Those records do not fully capture oceanic processes linked to NAO variability, and short instrumental records from relatively few locations limit the understanding of ocean-atmosphere dynamics with regard to NAO behavior. "By analyzing the coral, we were able to look at changes in the ocean relative to changes on land," said Nathalie Goodkin, lead author of the study published in the December issue of the journal Nature Geoscience. "Because they are slow growing and have long life-spans, corals can provide high resolution records that are well dated and centuries long." As they grow, corals accrete seasonal and annual growth layers, similar to tree rings. The proportions of trace elements versus the major element (calcium) found in the layers of the skeleton largely depend on the temperature of the seawater in which it was formed. By analyzing the strontium to calcium ratio in the Bermuda brain coral, Goodkin and colleagues -- WHOI scientists Konrad Hughen, Scott Doney and William Curry -- were able to reconstruct monthly changes in ocean temperatures and evaluate variability of the NAO during both cold and warm periods from the Little Ice Age (1800�) to modern day. The research team found the variability of the NAO decade-to-decade (multi-decadal scale) has been larger, swinging more wildly, during the late twentieth century than in the early 1800s, suggesting that variability is linked to the mean temperature of the Northern Hemisphere. This confirms variability previously reported in past terrestrial reconstructions. "When the Industrial Revolution begins and atmospheric temperature becomes warmer, the NAO takes on a much stronger pattern in longer-term behavior," said Goodkin. "That was suspected before in the instrumental records, but this is the first time it has been documented in records from both the ocean and the atmosphere." The North Atlantic Oscillation is described by the NAO index, calculated as a weighted difference between the polar low and the subtropical high during the winter season. In a positive phase, both the low-pressure zone over Iceland and high pressure over the Azores are intensified, resulting in changes in the strength, incidence, and pathway of winter storms crossing the Atlantic. In a negative phase, a weak subtropical high and a weak Icelandic low results in fewer and weaker winter storms crossing on a more west-east pathway. The NAO index varies from year to year, but also exhibits a tendency to remain in one phase for intervals lasting more than a decade. An unusually long period of positive phase between 1970-2000 led to the suggestion that global warming was affecting the behavior of the NAO. "Anthropogenic (human-related) warming does not appear to be altering whether the NAO is in a positive or negative phase at multi-decadal time scales," said WHOI paleoclimatologist Konrad Hughen. "It does seem to be increasing variability. Clearly, this has implications for the future." "As temperatures get warmer, there's potential for more violent swings of the NAO -- the phases becoming even more positive and even more negative," Hughen added. "If the NAO locks more into these patterns, intense storms will become more intense and droughts will become more severe." The climatic influence of the NAO extends from the eastern United States to Western Europe, impacting human activities such as shipping, oil drilling, fisheries, hydroelectric power generation and coastal management. Improving the ability to predict shifts in the phase and intensity of the NAO is a prerequisite to mitigating the economic impacts of future climate change. While additional modeling and palaeoclimatic studies are needed, a broad distribution of marine records could advance our knowledge of NAO variability and serve to improve future projections, said Goodkin, now an assistant professor in the Department of Earth Sciences at the University of Hong Kong. ### A WHOI Ocean and Climate Change Institute Fellowship, and grants from the National Science Foundation and Woods Hole Oceanographic Institution supported this work. The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans' role in the changing global environment. Related links: Nature GeoScience: Increased multidecadal variability of the North Atlantic Oscillation since 1781 http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo352.html

Picked up a quick .50 inch in Wantagh as the radar appears to be underestimating the tropical downpours.

First heavy downpour of the day here in SW Suffolk.

This is one of the most extreme dipole reversals on record for late August. The Arctic went from record high pressures to record low pressures in just a few weeks. It’s the first time in over a decade for a small gain in extent from 8-22 to 8-27. Shows what can happen with a rapid shift to colder and stormier conditions. 8-22 to 8-27 sea ice extent change 2019...+55k 2018...-134k 2017...-213k 2016....-507k 2015....-451k 2014....-165k 2013....-152k 2012....-431k 2011....-177k 2010....-262k 2009....-254k 2008....-439k 2007.....-71k

Only the 5th August since 2000 at Newark with 5 consecutive days under 80 degrees. 2019 2017 2007 2004 2000

Good thing this isn’t a winter snowfall forecast.

Pretty typical this decade to get a large August high temperature drop after reaching 100 in July. Monthly Highest Max Temperature for LA GUARDIA AP, NY Click column heading to sort ascending, click again to sort descending. Year Jun Jul Aug Season 2019 94 100 93 100 2018 96 97 98 98 2017 101 98 91 101 2016 90 99 98 99 2015 92 95 93 95 2014 88 93 92 93 2013 96 100 90 100 2012 98 101 93 101 2011 97 104 92 104 2010 96 103 95 103

People get scared when they see the continuing ecosystem destruction. So it’s not a surprise that rumors get started in this age of instant global communications. But at least running out of oxygen isn’t something to be worried about. https://theconversation.com/amp/amazon-fires-are-destructive-but-they-arent-depleting-earths-oxygen-supply-122369?utm_source=twitter&utm_medium=twitterbutton&__twitter_impression=true

Tough to generate much heat here in August with such a strong -EPO/-AO/-NAO pattern.

The IOD just rose above +1 for the first time since 2015. So there are currently cooler SST departures near Indonesia. Be interesting to see if some semblance of this pattern lingers into winter and can result in less Maritime Continent MJO forcing. But the warmth near and west of the dateline has been associated with a more active MJO in general. Also the very strong +NPM with near record SST warmth from just off the equator and northward.

The extent loss rate began to stall a few days before the storm around the 20th. The record breaking high pressure regime that had been in place since May reversed. So the ice pack became less compact and spread out with colder temperatures.

Strong -EPO pattern with plenty of Canadian high pressure. You can see how much the Northeast Pacific has warmed yet again in recent months. NPM has shot back up to +2.70.

Probably too early to tell about next winter. But we got a hint last fall with the unusual Pacific SST configuration and the rare SOI reversal. Maybe we get some type of signal this fall or we just have to wait until the winter. Every single DJFM this decade had some surprise not well seen in advance. This decade has been very unique for the odd combination of competing influences.