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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.

This may be a new late November record for lightning east of New England.

Mild week coming up with the potential for our first Thanksgiving 60° since 2015. https://www.weather.gov/media/okx/Climate/CentralPark/Thanksgivingwx.pdf KNYC GFSX MOS GUIDANCE 11/23/2020 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 MON 23| TUE 24| WED 25| THU 26| FRI 27| SAT 28| SUN 29| MON 30 CLIMO X/N 56| 38 49| 39 55| 50 61| 52 60| 51 61| 46 54| 44 51 35 48

Our unusually active late convection season continues this morning. BULLETIN - IMMEDIATE BROADCAST REQUESTED Special Marine Warning National Weather Service New York NY 645 AM EST Mon Nov 23 2020 The National Weather Service in Upton NY has issued a * Special Marine Warning for... Moriches Inlet to Montauk Point NY out 40 NM... Long Island Sound East of New Haven CT / Port Jefferson NY... Peconic and Gardiners Bays... * Until 730 AM EST. * At 644 AM EST, strong thunderstorms were located along a line extending from New London Harbor to 14 nm southwest of Buoy 44017, moving northeast at 45 knots. HAZARD...Wind gusts 34 knots or greater and small hail. SOURCE...Radar indicated. IMPACT...Small craft could be damaged in briefly higher winds and suddenly higher waves. * Locations impacted include... Watch Hill, Gardiners Island, Orient Point, Fishers Island Sound, Buoy 44017, Shelter Island Sound, Gardiners Bay, The Race, New London Harbor and Shelter Island.

NYC could see only the 5th 60° Thanksgiving since 1999. KNYC GFSX MOS GUIDANCE 11/22/2020 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 SUN 22| MON 23| TUE 24| WED 25| THU 26| FRI 27| SAT 28| SUN 29 CLIMO X/N 54| 50 55| 38 49| 36 52| 51 64| 50 58| 52 57| 49 54 35 48 https://www.weather.gov/media/okx/Climate/CentralPark/Thanksgivingwx.pdf 11-26-15...60° 11-22-07...66° 11-25-04...65° 11-25-99...61° https://www.weather.gov/media/okx/Climate/CentralPark/Top5Thanksgiving.pdf

It looks like the CONUS is on track for a top 5 warmest November. Numerous stations are in 1st place with just under 10 days to go. Pretty uniform warmth across the country. 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 53.3 9 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 Time Series Summary for Chicago Area, IL (ThreadEx) - Month of Nov Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2020 50.2 9 2 1931 50.0 0 3 1909 48.5 0 4 2001 48.2 0 5 1913 47.2 0 Time Series Summary for Goodland Area, KS (ThreadEx) - Month of Nov Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 2020 48.9 9 2 1999 46.4 0 3 1914 46.0 0 4 1949 45.7 0 5 2016 45.5 0

Remarkably consistent storm track since 2018 with 3 of the wettest years on record for higher elevations to our SW. Time Series Summary for HIGHLANDS, NC - Jan through Dec Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 2020 125.89 42 2 2018 125.46 0 3 1979 115.92 37 4 2019 111.78 0

NYC on track for a top 10 warmest November. Models have generally above normal temperatures for the remainder of the month. Today looks like the 2nd day in a row to reach 60°. KNYC GFSX MOS GUIDANCE 11/21/2020 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 SAT 21| SUN 22| MON 23| TUE 24| WED 25| THU 26| FRI 27| SAT 28 CLIMO X/N 60| 42 53| 48 55| 36 48| 40 55| 48 58| 43 54| 44 54 36 49 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 10 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

Yeah, similar to Elko, Nevada in late September. Almanac for Elko Area, NV (ThreadEx) September 27, 2020 Daily Data Observed Normal Record Highest Record Lowest Max Temperature 72 74 91 in 2010 43 in 1923 Min Temperature 34 35 51 in 1989 13 in 1889 Avg Temperature 53.0 54.2 67.5 in 1989 38.0 in 1999

Thanks for reminding me to run the 6 hr temperature rise numbers. That’s when we had a diurnal range similar to the high desert in Nevada during September. It tied the 6 hr biggest November temperature jump. There was a 44° low between hours with a total jump of 32°. But the data plotter below only works with the hourly temperatures.

Near record 30 hr November temperature jump coming for Friday. Places that were in the low 20s this morning will be near 60° Friday afternoon. So a 35 to 40° temperature rise. KISP GFSX MOS GUIDANCE 11/19/2020 1200 UTC FHR 24 36| 48 60| 72 84| 96 108|120 132|144 156|168 180|192 FRI 20| SAT 21| SUN 22| MON 23| TUE 24| WED 25| THU 26|FRI CLIMO N/X 39 59| 45 61| 39 54| 50 58| 34 46| 35 58| 47 57| 41 34 50 https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=NY_ASOS&zstation=ISP&hours=30&month=nov&dir=warm&dpi=100&_fmt=png

Yeah, drier air and light winds on the mornings with the best radiational cooling. Even when we had the record highs earlier in the month, the diurnal temperature range was close to the high desert of Nevada in September. We had several days with light winds, high pressure, lower dew points, and low air quality. This is what happens with the record 500mb ridging this month over the area. Also notice how strong the polar vortex has been in the Arctic.

This has to be the best radiational cooling that we have seen in such a warm November. ISP just tied the record low for 2 consecutive days. Notice how much higher the max departure than the min. ISP had 3 consecutive daily record highs earlier this month. Max...+5.1 Min...+1.6 Avg...+3.3 11/18 24 in 2020 24 in 2014 25 in 2017+ 11/19 22 in 2020 22 in 2014 23 in 1997 11/7 74 in 2020 67 in 1975 67 in 1971 11/8 76 in 2020 70 in 2011 68 in 1975 11/9 74 in 2020 73 in 1975 71 in 1994

The satellite and radar trends the day before looked like it was coming up the coast. But all the models were OTS. Imagine if when NYC had their heaviest snowstorm in January 2016 the models all had no snow the day before. This is what happened at RDU when they got their record 20.3” on 1-25-00. https://projects.ncsu.edu/atmos_collaboration/nwsfo/storage/cases/20000125/

That was the last time that the East Coast got a surprise major snowstorm when the models didn’t have any snow just a day before. http://voices.washingtonpost.com/capitalweathergang/2010/01/major_snowstorm_ambushes_washi.html

We may have to wait until another strong El Niño emerges to see a dominant STJ instead. Jan 16 was one of my all time favorites.

There were some similarities between the 99-00 and 11-12 La Ninas. Both featured a mild November and December. The biggest snowstorm of both winters occurred almost on the same date in late January. NYC 2000-01-25 30 25 27.5 -5.0 37 0 0.73 5.5 2 2012-01-21 29 22 25.5 -6.8 39 0 0.39 4.3 1

So we may finish November with average temperatures closer to the 2011 and 1999 La Ninas rather than than 2015 super El Niño. 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 55.1 13 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

Yeah, cool downs like today should be relatively brief with such a fast Pacific flow.

While we still warm up back to around 60° heading into the weekend, we may get a backdoor with more easterly flow and clouds on Sunday. KNYC GFSX MOS GUIDANCE 11/18/2020 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 WED 18| THU 19| FRI 20| SAT 21| SUN 22| MON 23| TUE 24| WED 25 CLIMO X/N 39| 31 50| 44 59| 50 60| 44 54| 49 60| 40 51| 44 56 37 50 TMP 36| 33 49| 47 55| 51 54| 46 53| 51 53| 41 47| 46 52 DPT 12| 17 26| 33 37| 40 35| 36 47| 46 41| 30 34| 39 39 CLD CL| CL CL| CL PC| PC PC| OV OV| OV OV| CL CL| OV OV

The NWS classified it as a macroburst. August 4th Macroburst https://www.weather.gov/okx/storm08042015 https://www.nssl.noaa.gov/education/svrwx101/wind/types/