bluewave

Yeah, the 6z NAM has a 4 to 5 SD 925 mb jet near the coast.

The fast Pacific flow will result in a day 6-10 warm up following the day 1-5 cool down. So the CONUS will finish with a much warmer November than the last few years. I posted the warmest rankings for the CONUS since 2010. Many areas just had a top 5 warmest first 2 weeks of November. NYC finished the first 2 weeks at 4th warmest. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 1 to Nov 14 Missing Count 1 1975-11-14 58.9 0 2 1938-11-14 57.6 0 3 2015-11-14 57.1 0 4 2020-11-14 56.6 0 - 1974-11-14 56.6 0 - 1935-11-14 56.6 0 CONUS warmest to coolest temperatures since 2011 201611 47.97°F 10 6.28°F 201711 45.03°F 9 3.34°F 201511 44.60°F 8 2.91°F 201211 44.01°F 7 2.32°F 201111 43.75°F 6 2.06°F 201011 42.31°F 5 0.62°F 201311 41.61°F 4 -0.08°F 201911 41.11°F 3 -0.58°F 201811 40.01°F 2 -1.68°F 201411 39.25°F 1 -2.44°F

It may be tough for Long Island to challenge the 9 year run averaging close to 50”. Monthly Total Snowfall for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Year Oct Nov Dec Jan Feb Mar Apr Season Mean 0.0 0.5 6.5 18.2 13.9 8.6 0.6 48.3 2009-2010 0.0 0.0 25.3 6.4 21.7 0.4 0.0 53.8 2010-2011 0.0 T 14.9 34.4 3.9 2.1 T 55.3 2011-2012 0.3 0.0 T 3.8 0.6 T 0.0 4.7 2012-2013 0.0 4.2 0.6 3.3 31.4 7.4 0.0 46.9 2013-2014 0.0 0.3 8.1 25.2 24.5 5.4 0.2 63.7 2014-2015 0.0 T 0.4 30.2 13.4 19.7 0.0 63.7 2015-2016 0.0 0.0 T 24.8 13.2 3.2 0.2 41.4 2016-2017 T T 3.2 14.0 14.7 7.4 T 39.3 2017-2018 0.0 T 6.0 22.0 1.4 31.9 4.6 65.9

Yeah, 93-94 and 95-96 were our only high snowfall seasons from 79-80 to 99-00. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Oct 1 to Apr 30 Missing Count 1980-04-30 12.8 0 1981-04-30 19.4 0 1982-04-30 24.6 0 1983-04-30 27.2 0 1984-04-30 25.4 0 1985-04-30 24.1 0 1986-04-30 13.0 1 1987-04-30 23.1 0 1988-04-30 19.1 0 1989-04-30 8.1 0 1990-04-30 13.4 0 1991-04-30 24.9 0 1992-04-30 12.6 0 1993-04-30 24.5 0 1994-04-30 53.4 0 1995-04-30 11.8 0 1996-04-30 75.6 0 1997-04-30 10.0 0 1998-04-30 5.5 0 1999-04-30 12.7 0 2000-04-30 16.3 0

The big low snowfall record left for NYC is a DJF or full snowfall season T. On the high side, NYC still hasn’t seen a 50” single storm in the modern era. A 10” in one hour would be another snowfall extreme we are yet to see. We should take bets on which of those 3 happens first.

I added it.

Only 79-80, 88-89, and 89-90 finished DJF with single digits. During the 90s it was 91-92, 96-97 , 97-98, and 98-99. Time Series Summary for NY CITY CENTRAL PARK, NY - Dec through Feb Click column heading to sort ascending, click again to sort descending. Season Total Snowfall Missing Count 1979-1980 8.2 0 1980-1981 10.8 0 1981-1982 14.3 0 1982-1983 26.4 0 1983-1984 13.5 0 1984-1985 23.9 0 1985-1986 13.0 1 1986-1987 21.2 0 1987-1988 18.0 0 1988-1989 5.6 0 1989-1990 5.0 0 Time Series Summary for NY CITY CENTRAL PARK, NY - Dec through Feb Click column heading to sort ascending, click again to sort descending. Season Total Snowfall Missing Count 1990-1991 24.7 0 1991-1992 3.2 0 1992-1993 12.6 0 1993-1994 45.3 0 1994-1995 11.8 0 1995-1996 58.8 0 1996-1997 8.2 0 1997-1998 0.5 0 1998-1999 8.2 0 1999-2000 14.7 0

The last 2 met winters were the first consecutive under 5” DJFs for NYC. After 09-10 to 17-18, I don’t think anyone would have made that bet. Just goes to show how extreme our climate has become. Time Series Summary for NY CITY CENTRAL PARK, NY - Dec through Feb Click column heading to sort ascending, click again to sort descending. Rank Season Total Snowfall Missing Count 1 1997-1998 0.5 0 2 1918-1919 1.1 0 3 1972-1973 2.6 0 4 1931-1932 2.7 0 5 1991-1992 3.2 0 6 2001-2002 3.5 0 7 2018-2019 3.7 0 8 2011-2012 4.5 0 9 2019-2020 4.8 0 10 1989-1990 5.0 0

Yeah, we have seen several -AO/+NAO splits in recent years. This wasn’t the case for the 09-10 and 10-11 winters. Notice how much different the DJF winter SSTs have been since 13-14. Much warmer SSTs off the East Coast and a cold pool south of Greenland.

Walt, great thread. 12z 3km NAM has one of the more impressive November low topped squall lines that we have seen in a while. The Euro shows 55 mph winds just off the deck near the coast. 12z NAM wind gust product has increased to 60 mph potential on Long Island.

The SE Ridge has only relaxed for 3 out of the last 15 DJF met winter months. The 3 winter months it hasn’t been a factor since the 15-16 winter were Dec 17, Feb 16, and Jan 16. We should probably develop a SE Ridge or WAR index like the other teleconnections since it has become such a dominant feature of our recent climate.

Very tough to get any extended cold with such a fast Pacific flow. Notice how we get cold for a few days following the Great Lakes lows. But the +EPO, +NAO, and SSTs allow a quick warm up and the SE Ridge flexes again.

The late November pattern looks similar to recent winters. Very fast Pacific flow and +EPO. The -AO blocking doesn’t look strong enough to eliminate the SE Ridge as the +NAO vortex holds on. So the primary storm track will remain through the Great Lakes. Ridges persist over the warm Atlantic and Pacific SST band along 40N.

Yeah, I just saw this story a few days ago.

Like Walt mentioned above, the Euro has 50 mph winds just off the deck which could mix down in low topped squall line gusts.

Those are some of the fastest rising SSTs on the planet.

That +13 December was one of the most extreme events that we have seen so far this century. The record breaking WAR was at the start of our warmest 5 winter stretch on record. It has been a dominant force through the year including the winters.

Yeah, notice how the SE Ridge and ridge south of the Aleutians make a quick return in about 10 days. This lines up really well with the band of near record warm SSTs around 40N across the Atlantic and Pacific.

Cooler pattern than the early part of the month coming up. The 500mb height anomalies will slowly shift poleward. So more blocking will promote a drop in temperatures. First 10 days of month Day 5 to day 10 EPS forecast

NYC actually had a more impressive warm minimum record than LGA. This is the first record stretch of warmth that I can remember when NYC had warmer minimums than LGA. The low of 64° in NYC is the 4th highest for the month of November. It was also the warmest 11-5 to 11-11 on record. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Mean Avg Temperature Nov 5 to Nov 11 Missing Count 1 2020-11-11 64.6 0 2 1975-11-11 63.1 0 3 1938-11-11 59.7 0 4 1948-11-11 58.7 0 5 2015-11-11 57.9 0 Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Nov Click column heading to sort ascending, click again to sort descending. Rank Year Highest Min Temperature Missing Count 1 1971 67 0 2 2015 66 0 3 1956 65 0 4 2020 64 19 - 2018 64 0 - 1938 64 0 - 1936 64 0 - 1929 64 0 - 1895 64 0

Looks like a step down in temperatures following the record November 70° day steak. Maybe a week away from a freeze around NYC. KEWR GFSX MOS GUIDANCE 11/12/2020 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 THU 12| FRI 13| SAT 14| SUN 15| MON 16| TUE 17| WED 18| THU 19 CLIMO X/N 61| 47 56| 40 54| 40 59| 51 55| 36 49| 31 43| 27 43 37 53 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Nov Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Max Temperature >= 70 Missing Count 1 2020 7 19 - 1975 7 0 2 1994 6 0 - 1990 6 0 - 1953 6 0 - 1931 6 0 3 2015 5 0 - 2001 5 0 - 1982 5 0 - 1938 5 0 Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Nov Click column heading to sort ascending, click again to sort descending. Rank Year Number of Days Max Temperature >= 70 Missing Count 1 1953 7 0 2 2020 6 19 - 1994 6 0 - 1975 6 0 3 2015 5 0 - 1938 5 0 - 1931 5 0 - 1927 5 0

Yeah, looks like the new record for this late in the year. Record rainfall and dew points to our south.

Impressive record to our south.

Could be the highest PWAT so late in the year for OKX with the heavy rains around the 0z sounding. Precipitable water: 1.93 inches