bluewave

Less warm is the new cool.

Extremely amplified pattern coming up. Record 500mb heights forecast along the West Coast by the weekend. Then we see how strong the ridge off the East Coast can get in 7-10 days.

Yeah, those warming WPAC SSTs lead to the record MJO 4-6 activity during recent winters. This served to enhance the La Niña background state over the last 4 winters. It resulted in mild to record warm winters with the SE Ridge dominating and setting a new record in February 2018. But the location of the NPAC ridge made the difference between snowy and nearly snowless winter outcomes. 2017 to 2018 featured the ridge near the Aluetians and more NATL blocking with a snowy pattern. During the 2019 to 2020 period ,the ridge was much flatter near Hawaii. So we got the two recent nearly snowless DJF periods along with a strong NATL PV. While it looks like we could experience a 5th La Niña background state winter, we’ll have to see how the NPAC ridge and NATL pattern influence the snowfall potential.

Updated for August 2020. 8....2020...EWR...10..LGA...5...BDR...3...ISP....6

I wonder what the 500MB height record is for Newfoundland in September? All the models are going near 600 DM In about 10 days.

It looks like we will have a trough in the Great Lakes and Midwest at least into early September. There should also be plenty of high pressure to our north and east with onshore flow here. But we will just have to wait and see how many of the AEWs coming off Africa can actually develop into named systems.

It took until last October for the IO standing wave to emerge with the record +IOD. It continued until mid-December before the record SSTs north of Australia emerged. Then it was off to the races for the record MJO 4-6 which dominated from late December on. There was some research that the IO standing wave being so strong during OND was related to the intense PV which dominated last winter. So it will be interesting so see how the Indian Ocean and Pacific interact this coming fall and winter.

The record breaking IO standing wave is making headlines again. Now it looks like it’s producing an early September pattern resembling MJO phase 1. So this translates into the big ridge along the West Coast and trough over the MW/GL. It will limit our early September 90° potential.

It really depends on how long the ridge says locked in along the West Coast. This hasn’t been our typical September pattern during the last decade. There has usually been a trough out there with a ridge over New England.

I agree that the MYI loss is the big story. https://climate.nasa.gov/news/2817/with-thick-ice-gone-arctic-sea-ice-changes-more-slowly/ With thick ice gone, Arctic sea ice changes more slowly The Arctic Ocean's blanket of sea ice has changed since 1958 from predominantly older, thicker ice to mostly younger, thinner ice, according to new research published by NASA scientist Ron Kwok of the Jet Propulsion Laboratory, Pasadena, California. With so little thick, old ice left, the rate of decrease in ice thickness has slowed. New ice grows faster but is more vulnerable to weather and wind, so ice thickness is now more variable, rather than dominated by the effect of global warming. Working from a combination of satellite records and declassified submarine sonar data, NASA scientists have constructed a 60-year record of Arctic sea ice thickness. Right now, Arctic sea ice is the youngest and thinnest its been since we started keeping records. More than 70 percent of Arctic sea ice is now seasonal, which means it grows in the winter and melts in the summer, but doesn't last from year to year. This seasonal ice melts faster and breaks up easier, making it much more susceptible to wind and atmospheric conditions. Working from a combination of satellite records and declassified submarine sonar data, NASA scientists have constructed a 60-year record of Arctic sea ice thickness. Right now, Arctic sea ice is the youngest and thinnest its been since we started keeping records. More than 70 percent of Arctic sea ice is now seasonal, which means it grows in the winter and melts in the summer, but doesn't last from year to year. This seasonal ice melts faster and breaks up easier, making it much more susceptible to wind and atmospheric conditions. Kwok's research, published today in the journal Environmental Research Letters, combined decades of declassified U.S. Navy submarine measurements with more recent data from four satellites to create the 60-year record of changes in Arctic sea ice thickness. He found that since 1958, Arctic ice cover has lost about two-thirds of its thickness, as averaged across the Arctic at the end of summer. Older ice has shrunk in area by almost 800,000 square miles (more than 2 million square kilometers). Today, 70 percent of the ice cover consists of ice that forms and melts within a single year, which scientists call seasonal ice. Sea ice of any age is frozen ocean water. However, as sea ice survives through several melt seasons, its characteristics change. Multiyear ice is thicker, stronger and rougher than seasonal ice. It is much less salty than seasonal ice; Arctic explorers used it as drinking water. Satellite sensors observe enough of these differences that scientists can use spaceborne data to distinguish between the two types of ice. Thinner, weaker seasonal ice is innately more vulnerable to weather than thick, multiyear ice. It can be pushed around more easily by wind, as happened in the summer of 2013. During that time, prevailing winds piled up the ice cover against coastlines, which made the ice cover thicker for months. The ice's vulnerability may also be demonstrated by the increased variation in Arctic sea ice thickness and extent from year to year over the last decade. In the past, sea ice rarely melted in the Arctic Ocean. Each year, some multiyear ice flowed out of the ocean into the East Greenland Sea and melted there, and some ice grew thick enough to survive the melt season and become multiyear ice. As air temperatures in the polar regions have warmed in recent decades, however, large amounts of multiyear ice now melt within the Arctic Ocean itself. Far less seasonal ice now thickens enough over the winter to survive the summer. As a result, not only is there less ice overall, but the proportions of multiyear ice to seasonal ice have also changed in favor of the young ice. Seasonal ice now grows to a depth of about six feet (two meters) in winter, and most of it melts in summer. That basic pattern is likely to continue, Kwok said. "The thickness and coverage in the Arctic are now dominated by the growth, melting and deformation of seasonal ice." The increase in seasonal ice also means record-breaking changes in ice cover such as those of the 1990s and 2000s are likely to be less common, Kwok noted. In fact, there has not been a new record sea ice minimum since 2012, despite years of warm weather in the Arctic. "We've lost so much of the thick ice that changes in thickness are going to be slower due to the different behavior of this ice type," Kwok said. Kwok used data from U.S. Navy submarine sonars from 1958 to 2000; satellite altimeters on NASA's ICESat and the European CryoSat-2, which span from 2003 to 2018; and scatterometer measurements from NASA's QuikSCAT and the European ASCAT from 1999 to 2017.

Updated for July 2020. 7....2020...EWR...5...NYC...7...LGA...1.....JFK...4...BDR....1...ISP....4

Updated for the 3.17 in Montclair, NJ with Tropical Storm Fay. 7/11/2020 8:00 AM NJ-ES-31 Montclair 0.7 N 3.17 NA | NA NA | NA NJ Essex

Updated for June 2020 6....2020...EWR..10..LGA...3...BDR...5.....ISP....5

Updated for the 3.99 at Bridgeport on July 3rd.

This record +AO pattern was more like something we saw around 1990. https://nsidc.org/arcticseaicenews/ Previous studies, led by University of Washington scientist Ignatius Rigor (e.g., Rigor et al., 2002), suggest that a positive winter phase of the Arctic Oscillation favors low sea ice extent the subsequent September. Wind patterns “flush” old, thick ice out of the Arctic Ocean through the Fram Strait and promote the production of thin ice along the Eurasian coast that is especially prone to melting out in summer. However, in recent years, this relationship has not been as clear (Stroeve et al., 2011). The potential effects this winter’s positive AO on the summer evolution of ice extent and the September 2020 minimum bears watching.

If the rate of warming since 1980 continues, then we are on track for +1.5 C of warming around 2035.

Updated for top 10 warmth in February 2020. 2....2020...EWR...6...NYC...6...LGA....8...JFK...4...BDR...5....iSP...3

Updated for the top10 warmth in January 2020. 1....2020...EWR...9...NYC...9...LGA....7...JFK...6...BDR...3....ISP...6

2nd warmest year for the Arctic behind 2016.

Record low Arctic sea ice extent for the Chukchi Sea in 2019.

Updated for 3.44 in Woodbury, NY. https://nwschat.weather.gov/p.php?pid=201912141224-KOKX-NOUS41-PNSOKX WOODBURY 3.44 704 AM 12/14 CWOP

The record amount of open water for the Chukchi Sea continues to be one of the big stories this year.

That was a very cold -NAO/+PNA pattern for the first week of December 2003. It was the snowiest first week of December and the 11th coldest for NYC.