bluewave

Convection developing to our south now.

Gusting to 63 mph just north of ACY.

NYC tied for warmest November with a day to go. 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 Mean Avg Temperature Missing Count 1 2020 52.8 1 - 2015 52.8 0 2 2001 52.7 0 3 1979 52.5 0 4 1948 52.4 0 5 1975 52.3 0 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 Mean Avg Temperature Missing Count 1 2015 52.0 0 - 1994 52.0 0 3 2001 51.9 0 1979 51.7 0 - 1975 51.7 0 4 2020 51.4 1 5 2006 51.3 0 Time Series Summary for LAGUARDIA AIRPORT, NY - Month of Nov Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2020 54.2 1 2 2001 53.5 0 3 2006 53.4 0 4 2015 53.3 0 5 1975 52.6 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY - Month of Nov Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2015 49.9 0 2 2011 49.8 0 3 2006 49.7 0 4 2020 49.3 1 - 1994 49.3 0 - 1975 49.3 0

It has been an ongoing issue for the GEFS. I can’t wait until machine learning brings us bias corrected model guidance maps. Maybe someday we can look at day 11-15 bias corrected maps which will take long range forecasting to the next level. But that will probably require quite a bit more computer power.

The first week of December will start out milder in the Northeast than some of the guidance was indicating a week ago. New run Old run

Walt, great thread as usual. The 12z NAM has 70kt down to 950 mb on Long Island Monday afternoon. The 6z run indicated that this would be a 5 SD LLJ event. The NAM also has an elevated convection sounding which could enhance severe or damaging wind gust potential in excess of 60 mph on Long Island.

NYC still in 1st place for warmest November with a warm finish to the month coming up. Very extensive warmth across the entire CONUS. So the whole country on average is close to a top warmest November. 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 Mean Avg Temperature Missing Count 1 2020 53.0 2 2 2015 52.8 0 3 2001 52.7 0 4 1979 52.5 0 5 1948 52.4 0 6 1975 52.3 0 7 2011 51.9 0 - 2006 51.9 0 - 1994 51.9 0 - 1931 51.9 0 8 1902 51.4 0 9 2009 51.1 0 10 1999 50.8 0

2016 to 2018 featured great snowstorms that melted a few days later in many cases. 2014 to 2015 had long lasting snow cover but the storms weren’t as impressive in my area as 2016 to 2018. 2010-2011 was the rarest of them all with great snowstorms and long lasting snow cover. I can still remember the snow mountains from the road crews piled high near the LB Boardwalk into the spring.

I don’t really mind if the snow melts a few days later. Our snowy 15-16, 16-17, and 17-18 winters featured big warm ups following most snowstorms. Kind of like spring in the Rockies. But it isn’t the greatest if you run a ski resort and have to put up with the sloppy conditions.

The cutter and hugger storm tracks can really produce for the areas around the Great Lakes. But all the warmth gets tired during the summer when people go north to cool off. Last several summers you had to go up into Canada to escape the heat.

You usually have to be north of I-80 to cash in on gradient snowfall patterns. EWR to ISP finished last December in the 2-4” range. The one exception was the cold 93-94 gradient. But even that one hit diminishing returns the closer you got to Philly.

3-21-18 was my last 10” event. It was also my 2nd favorite late season snowstorm behind 4-6-82. https://www.weather.gov/okx/storm03212018

The duration of multiyear below normal snowfall regimes can be uncertain. But it usually takes a 10.0”+ event to get the ball rolling back in the right direction. Great pattern breaking snowstorms like 1-20-78, 3-13-93, and 12-30-00 come to mind.

The 53.1° average November temperature in NYC is normal for South Carolina. Monthly Climate Normals (1981-2010) - GRNVL SPART INTL AP, SC November 52.4

NYC currently in the lead for the warmest January through November on record. This is the 5th top 10 warmest January through November since 2010. 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 Jan 1 to Nov 30 Missing Count 1 2020-11-30 59.1 4 2 2016-11-30 59.0 0 - 2010-11-30 59.0 0 3 1991-11-30 58.9 0 4 2012-11-30 58.8 0 5 1990-11-30 58.7 0 6 1953-11-30 58.6 0 - 1949-11-30 58.6 0 7 1998-11-30 58.5 0 8 2017-11-30 58.4 0 - 2002-11-30 58.4 0 9 2006-11-30 58.1 0 - 1999-11-30 58.1 0 10 1983-11-30 58.0 0

Very warm end to November should allow NYC to finish near the top of the warmest Novembers list. KNYC GFSX MOS GUIDANCE 11/27/2020 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 FRI 27| SAT 28| SUN 29| MON 30| TUE 01| WED 02| THU 03| FRI 04 CLIMO X/N 60| 46 58| 42 57| 48 60| 50 54| 36 45| 38 47| 39 46 34 47 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 Mean Avg Temperature Missing Count 1 2020 53.0 4 2 2015 52.8 0 3 2001 52.7 0 4 1979 52.5 0 5 1948 52.4 0 6 1975 52.3 0 7 2011 51.9 0 - 2006 51.9 0 - 1994 51.9 0 - 1931 51.9 0 8 1902 51.4 0 9 2009 51.1 0 10 1999 50.8 0

Looks like LGA tied the record high of 67°. This is a normal Thanksgiving for Charleston, SC. So another example of the subtropical climate zone shifting north. https://www.wrh.noaa.gov/mesowest/getobext.php?sid=KLGA&table=1&num=168&banner=off Almanac for LAGUARDIA AIRPORT, NY November 26, 2020 Daily Data Observed Normal Record Highest Record Lowest Max Temperature 67 51 67 in 1946 34 in 1974 Almanac for Charleston Area, SC (ThreadEx) November 26, 2020 Daily Data Observed Normal Record Highest Record Lowest Max Temperature M 67 82 in 1973 41 in 1938

65° at Newark. Getting close to the record high of 68° set back in 2011. Newark Liberty PTSUNNY 65 59 81 SW16 29.95F Almanac for NEWARK LIBERTY INTL AP, NJ November 26, 2020 Daily Data Observed Normal Record Highest Record Lowest Max Temperature M 51 68 in 2011 29 in 1938

This month the very strong IO MJO combined with a near record polar vortex for November record warmth. So it really enhanced the upper ridge over the area. The closest MJO composite match for November was a phase 3. You can see the dominant VP anomalies focused near that part of the IO.

We are on track for a top 5 warmest Thanksgiving across the area. Parts of LI are already in the low 60s at 7am. Shirley LGT RAIN 61 55 81 S9 https://www.weather.gov/media/okx/Climate/CentralPark/Top5Thanksgiving.pdf NYC #1....69° #2....66° #3....65° #4....64° #5....62°

This may be the first time that NYC had 8 consecutive warmer than average falls. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Mean Avg Temperature Departure 2020 59.8 +2.3 2019 58.1 +0.6 2018 57.6 +0.1 2017 60.4 +2.9 2016 60.1 +2.6 2015 61.8 +3.3 2014 58.2 +0.7 2013 57.8 +0.3 2012 56.9 -0.6

Discuss...

12z Euro would be a continuation of our unusually active late fall convection pattern. Has an impressive low topped squall to start December with early morning temps in the 60s.

NYC holding in 1st place for warmest November by a narrow margin with several more 60° days possible. KNYC GFSX MOS GUIDANCE 11/24/2020 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 TUE 24| WED 25| THU 26| FRI 27| SAT 28| SUN 29| MON 30| TUE 01 CLIMO X/N 49| 40 56| 49 62| 51 61| 51 62| 43 49| 45 56| 42 45 35 48 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 Mean Avg Temperature Missing Count 1 2020 53.2 7 2 2015 52.8 0 3 2001 52.7 0 4 1979 52.5 0 5 1948 52.4 0 6 1975 52.3 0 7 2011 51.9 0 - 2006 51.9 0 - 1994 51.9 0 - 1931 51.9 0 8 1902 51.4 0 9 2009 51.1 0 10 1999 50.8 0

Do you think the Euro is showing its bias in holding too much energy back to the SW? Its12z depiction of a SE coastal low looks much different than the 12z GFS,CMC, and UKMET. The GFS, UKMET, and CMC have a warmer storm track closer to our area.