bluewave

Even the Canadian which can sometimes have a cold bias has 80°.

Looks like the CPC is going with the Euro seasonal which has the warm Nino +PNA ridge to the north undercut by the -PDO trough near the southern Rockies. With a +PDO El Niño the trough would be over the Southeast. But it’s pulled west due to the -PDO in the seasonal forecasts. If we see the same error as the seasonal forecasts last winter, then the trough out West will be deeper pumping the ridge more in the East. You can see the Euro seasonal maintaining the Niña -PDO ridge north of Hawaii. But it also has the Nino +PNA ridge in Canada. Need to lose the -PDO and ridge north of Hawaii for the El Niño to be able to be the main driver.

It has been a split flow pattern. But the northern branch looks to dominate next weekend with the strong -PNA pattern. So some late season Niña-like 80° heat possible for the Northern Mid-Atlantic.

Models now indicating record 80° heat possible for next weekend. Maybe we can finally break the streak of rainy weekends. This would be the warm and sunny weekend which was so elusive all summer. Newark Area, NJPeriod of record: 1893-01-01 through 2023-10-21DateHighest maximum temperatures (degrees F 10/28 82 in 1984 81 in 1919 78 in 1989+ 10/29 78 in 1971 78 in 1946 76 in 1989 10/30 82 in 1946 80 in 1961 80 in 1950

The actual 500 mb pattern this month is classic MJO 6 with the deep Scandinavian trough and Hudson Bay ridge. I guess we can chalk it up to atmospheric lag since the MJO has been stuck in phases 4-6 for so many years. It’s as if the atmosphere isn’t even registering the subsidence near the Maritime continent with the near record +IOD.

The much lower upper ocean heat than usual for a strong El Niño is causing Nino 3.4 to struggle to push past +1.7 over the last month.

Blocking near Hudson Bay is classic La Niña in October. But this is even extreme for a La Niña. Somewhat similar to the La Niña in 2021. So not a very Nino-like North American pattern this October.

The first time the upper ocean heat anomalies during a developing El Niño were +.40 warmer in June than October. https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ocean/index/heat_content_index.txt

Relative to the means, the warm up next week will be more impressive than the cool down.

I liked the 17-18 winter into spring record snowfall much better than 18-19 and 19-20 following the record cold in November. Newark Area, NJPeriod of record: 1893-01-01 through 2023-10-19 Lowest minimum temperatures (degrees F)Top Record 2nd Record 3rd Record 11/10 25 in 2017 27 in 2004 27 in 1914 11/11 24 in 2017 25 in 1956 25 in 1933 11/12 25 in 2019 28 in 2017 28 in 1904+ 11/13 22 in 2019 24 in 1986 25 in 1920+ 11/14 18 in 1905 21 in 1986 24 in 2019 11/15 18 in 1933 21 in 1942 21 in 1905 11/16 15 in 1933 20 in 1967 22 in 1996+ 11/17 18 in 1933 21 in 1980 23 in 1900 11/18 19 in 1936 21 in 1959 21 in 1904 11/19 19 in 1936 21 in 2014 24 in 1903 11/20 21 in 1984 21 in 1894 22 in 1901 11/21 18 in 1987 21 in 1903 22 in 1910 11/22 17 in 2018 19 in 1987 22 in 1949 11/23 13 in 2018 21 in 1932 22 in 1949

I believe the WCS daily PDO updates are based on mantua PDO index and not the NOAA PDO index. So each version of the index varies from the other. Plus the key area north and NW of Hawaii is what matters for our sensible weather rather than the absolute PDO values. But when the are aligned like last winter into spring we had the strongly coupled -PDO trough in the West.

That is a very nice rise. We just need a decent cold pool and Aleutian low north or northwest Hawaii to push back against the tendency for too strong an Aleutian ridge. We want the El Niño to be the primary driver of the pattern. This way even if the winter continues the warmer theme of recent years, a juiced STJ can deliver better snowfall than last winter.

They are talking about localized sea level rise with the El Nino in the Tropical Pacific from the warmer SSTs not the ongoing global sea level rise. https://climate.nasa.gov/news/3286/international-ocean-satellite-monitors-how-el-nino-is-shaping-up/#:~:text=By October 1997 and 2015,the 1997 and 2015 events. Not all El Niño events are created equal. Their impacts vary widely, and satellites like the U.S.-European Sentinel-6 Michael Freilich help anticipate those impacts on a global scale by tracking changes in sea surface height in the Pacific Ocean. Water expands as it warms, so sea levels tend to be higher in places with warmer water. El Niños are characterized by higher-than-normal sea levels and warmer-than-average ocean temperatures along the equatorial Pacific. These conditions can then propagate poleward along the western coasts of the Americas. El Niños can bring wetter conditions to the U.S. Southwest and drought to regions in the western Pacific, including Indonesia. This year’s El Niño is still developing, but researchers are looking to the recent past for clues as to how it is shaping up. There have been two extreme El Niño events in the past 30 years: the first from 1997 to 1998 and the second from 2015 to 2016. Both caused shifts in global air and ocean temperatures, atmospheric wind and rainfall patterns, and sea level. The maps above show sea levels in the Pacific Ocean during early October of 1997, 2015, and 2023, with higher-than-average ocean heights in red and white, and lower-than-average heights in blue and purple. Sentinel-6 Michael Freilich captured the 2023 data, the TOPEX/Poseidon satellite collected data for the 1997 image, and Jason-2 gathered data for the 2015 map. By October 1997 and 2015, large areas of the central and eastern Pacific had sea levels more than 7 inches (18 centimeters) higher than normal. This year, sea levels are about 2 or 3 inches (5 to 8 centimeters) higher than average and over a smaller area compared to the 1997 and 2015 events. Both of the past El Niños reached peak strength in late November or early December, so this year’s event may still intensify. “Every El Niño is a little bit different,” said Josh Willis, Sentinel-6 Michael Freilich project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “This one seems modest compared to the big events, but it could still give us a wet winter here in the Southwest U.S. if conditions are right.”

The paper had an increase in PNA blocking only during the winter and not NAO blocking. The eruption was in January 2022. So 3-7 years wouldn’t be be until next winter. But it’s just one study so we’ll have to see if the winter PNA blocking increases in 24-25. So the record blocking over Canada since May is probably related to the general increase in these stuck 500 mb ridges in recent years and not the volcanic eruption.

Thanks. Just saw that. The blocking influence from the eruption on the composites is mostly during the winter and largely absent during the warm season. So maybe this is just a continuation of the 500 mb ridges that have been getting stuck in place during recent years as the planet warms.

All of Canada has experienced historic blocking beyond anything we have seen in the past from May to October. But none of the El Niño or -PDO composites have a block like this. So there has to be something else at work. Probably a combination of factors. The chart below will be even more impressive when it gets updated to include October. Brian B made a post about this when it started back in May.

It can definitely be an issue early in the season like 12-05-20 with a storm bombing out to our SE and no cold. Things got better a few weeks after that. But BGM was favored with the 40” jackpot since the low was so tucked in near ACY.

Great blocking pattern and trough this month but a lack of cold air to go along with it.

The one thing that has changed since the 70s to 90s is that we have more 50+ and 60+ days close to our snowstorms. So the snow has started to melt pretty quickly after the snowstorms. I don’t mind this since it’s more like what our spring snowstorms from the past used to be like. One of my all-time favorites snowstorms was April 1982. I didn’t mind that it was in the 60s in the days before and after the snow. So I will gladly trade extended snow cover for great KU events.

JMA is one site with monthly composites based on ENSO. They have more detail than the ESRL maps. https://ds.data.jma.go.jp/tcc/tcc/products/clisys/enso_statistics/index.html

All we know so far is that this month is a blend of El Niño and La Niña composites probably due to the -PDO. The end result is that the troughs under the blocking don’t have much cold air to work with. Plus this has been the warmest October on record globally.

02-03 was a great winter with the best Christmas Day snowstorm on record for parts of Long Island. Plus one of our greatest KU’s of all time in February. Then the bonus late season snows. So I would also rank it high. Data for December 25 - ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature Precipitation Snowfall Snow Depth 2002-12-25 41 30 1.29 8.0 M 1966-12-25 32 22 0.13 2.3 7 1969-12-25 31 13 0.10 1.0 0 2017-12-25 40 28 0.24 T 0 2003-12-25 47 33 T T 0 1992-12-25 40 13 T T 0 1985-12-25 41 19 T T 0 1976-12-25 40 14 T T 0 1975-12-25 40 8 0.14 T 2

While we have had much bigger snowstorms than any individual event in 93-94, the January ice storm still stands as our benchmark event along with January 1978. It was the last time areas west of NYC dropped from -15 to -30. Jan 94 was Allentown’s version of Feb 34 in NYC. It was the last time downtown Philly dropped to -5. Also the coldest temperature on record for Sussex County, NJ at -29. Monthly Data for January 1994 for Mount Holly NJ NWS CWA Click column heading to sort ascending, click again to sort descending. State Name Station Type Lowest Min Temperature PA BLUE MARSH LAKE COOP -29 NJ SUSSEX 1 NW COOP -29 NJ NEWTON COOP -26 PA PALMERTON COOP -23 PA BUCKSVILLE COOP -23 PA BELTZVILLE DAM COOP -22 PA READING 4 NNW COOP -20 NJ SUSSEX 8 NNW COOP -20 PA HAMBURG COOP -19 PA SPRINGTOWN 1 NNE COOP -18 NJ LONG VALLEY COOP -18 PA GRATERFORD 1 E COOP -17 NJ BELVIDERE BRIDGE COOP -17 PA ALLENTOWN LEHIGH VALLEY INTERNATIONAL AIRPORT WBAN -15 NJ FLEMINGTON 5 NNW COOP -15 Time Series Summary for Allentown Area, PA (ThreadEx) - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 1994 -15 0 2 1961 -12 0 - 1934 -12 7 3 1984 -11 0 - 1942 -11 0 4 1954 -10 1 Time Series Summary for NY CITY CENTRAL PARK, NY - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 1934 -15 0 2 1917 -13 0 3 1943 -8 0 4 1933 -6 0 - 1918 -6 0 - 1899 -6 0 - 1882 -6 0 - 1880 -6 1 Time Series Summary for PHILADELPHIA FRANKLIN INSTITUTE, PA - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 1994 -5 17 2 2015 1 9 3 2014 3 2 Time Series Summary for SUSSEX 1 NW, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Lowest Min Temperature Missing Count 1 1994 -29 137 2 1961 -25 1 3 1912 -24 9 4 1967 -23 6 5 1981 -22 1 - 1968 -22 40

Perfect balance of blocking near Greenland and Alaska with a great SW ridge near California. It was the only time a station on Long Island had a 90” season. It might have been a 100 to 200 year event if we had snowfall data going back that far on Long Island. It was as close to a perfect winter and snowfall season that our area has had in modern times. A great KU, high number of days with snow cover, and wall to wall cold from November into April but not overpowering. On a scale of 100 for ranking a winter, it would probably be the only year in my lifetime that I would grade a 95 or higher A+. I would probably rank the 10-11 and 77-78 seasons a close 2nd around 90. https://www.bnl.gov/weather/4cast/monthlysnowfall.htm