bluewave

Also an impressive new November daily snowfall record for Detroit.

Very sharp Arctic front as expected. Snowing and 30 in Scranton with upper 50’s on Long Island. Root for the HRDPS and Euro if you want to see some wet flakes later in the mix. Scranton SNOW 30 26 85 W7 29.83R VSB 1/2 WCI 23 Montauk N/A 59 52 77 SW10G17 29.71F

A 20’s seasonal snowfall total was more common at BNL through the 90’s. But the last one was 1998-1999. https://www.bnl.gov/weather/4cast/MonthlySnowfall.htm

These Arctic anafronts usually don’t have much moisture. It either ends as light rain or a brief changeover to non-accumulating light snow near NYC and coast. But it would be nice if some spots can see their first T of the season.

No problem. The 950 mb benchmark blizzard tweet was epic.

Yeah, it was well advertised by several of the models.

This is during the snowiest decade of all time for parts of the region. Imagine what the weather forums would have been like from 79/80-91/92.We can also add 96/97 -01/02 to the list.

The NAM has a 20 + degree temperature drop for Long Island in just 6 hrs on Tuesday. Early morning 50’s to low 30’s by mid afternoon.

Picking up at least a T by November 15th has been common this decade. Time Series Summary for NEWARK LIBERTY INTL AP, NJ Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Snowfall Oct 1 to Nov 15 Missing Count 1 2018-11-15 6.4 0 2 2017-11-15 T 0 3 2016-11-15 0.0 0 - 2015-11-15 0.0 0 5 2014-11-15 T 0 - 2013-11-15 T 0 7 2012-11-15 6.2 0 8 2011-11-15 5.2 0 9 2010-11-15 T 0

The 12z NAM has the first T of the season at the local airports on Tuesday.

Record cold in the East and record warmth in Alaska has been our new November default pattern.

Yeah, only 2 solid -NAO Decembers with an El Niño since 2000. We got favorable MJO phases for a -NAO during December 2002 and 2009. Notice how the MJO mostly avoided the Maritime Continent phases. During recent Decembers, the MJO always found a way to focus in phases 4 and 5. So the MJO will be important to track as we head into December.

The Euro has something for everyone on Tuesday. Highs of 55-60 on Long Island early in the morning. Then a sharp cold front and the precipitation ending as snow during the day. Followed by near record cold Wednesday.

Our best winter forecast skill this decade has been the timing or sequence of the monthly temperature departures. But the magnitude of those departures has been a surprise. When taking the entire OKX forecast area into account, snowfall totals have also been difficult to pin down before the season started. Maybe some years demonstrated relative success in snowfall forecasts for NYC. But the extreme totals at some places like Islip have blown past expectations of winter forecasts. Seasonal forecasts have been very poor at handling the actual extremes that defined the 2010’s.

The key is actually verifying a -NAO during December. Expecting one since 2011 has been like betting against the house. Last 8 years have been the most positive December +NAO streak on record. So it will be interesting to see if this year can push back against the recent decadal pattern.

Yeah, a strong Aleutian low in November is typically found with El Niños.This time we have the much intense -EPO blocking of recent Novembers combined with it. So maybe the atmosphere will follow an El Niño progression this year. But the wild card is what the NAO does in December. The default El Niño December is mild for us. So -NAO is required for colder and snowier outcomes like 2002.The NAO has been in a positive state in December since 2011.

This matches the pattern pretty well. We can still get record cold as the climate warms. But the ratio of record highs to record lows keeps increasing. Record Arctic outbreaks also occupy a much smaller area now. You can see how the October record cold in the Western US was like a tiny ice cube in a global sea of warmth.

Some arctic sea smoke earlier today on parts of the Sound.

We should make the list again this year with the projected low 20’s for NYC early Wednesday.

The low of 27 this morning in NYC is 2nd earliest on record behind 1879. Tied the record low of 29 yesterday. All the more impressive following the latest mid 90’s around NYC in early October. A few days earlier than the record cold in 2017. That record cold followed the warmest October on record around the area at +7.2. So the record warmth in October followed by record cold in November continues. 11/8 29 in 2019 29 in 1886 30 in 1992+ 11/9 24 in 1976 27 in 2019 29 in 2003+ Earliest 27 degree temperature or lower in NYC Frost/Freeze Summary for NY CITY CENTRAL PARK, NY Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length 1879 04-06 (1879) 26 11-04 (1879) 25 211 1976 04-12 (1976) 25 11-09 (1976) 24 210 1914 04-04 (1914) 27 11-10 (1914) 27 219 2017 03-23 (2017) 23 11-10 (2017) 25 231

NYC only missed the record low max by 3 degrees. 11/8 38 in 1886 MAXIMUM 41 1222 AM 57 -16

This is probably the closest the first fall freeze has been to the last mid 90’s around NYC. The shortest reversal of this pattern I could find for the spring was April 1976. Newark 2019-10-02 96 67 81.5 19.8 NYC 1976-04-12 43 25 34.0 -17.9 1976-04-18 96 70 83.0 29.0

The key to getting a cold and snowy December with the 2002, 2000, and 1995 cases was a -NAO.

Years that remained cold for both months finished in the top 20 coldest winter average temperatures since 1950. The forum really enjoyed the 02-03 and 95-96 snowfall outcomes. They would have liked 00-01 more if some of the March snowstorm forecasts verified. Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Rank Season Mean Avg Temperature Missing Count 1 1976-1977 28.4 0 2 1962-1963 29.9 0 3 1977-1978 30.3 0 4 1969-1970 30.5 0 5 1958-1959 30.8 0 6 1993-1994 31.1 0 7 2002-2003 31.2 0 - 1967-1968 31.2 0 8 2014-2015 31.4 0 9 1960-1961 31.7 0 10 1970-1971 32.1 0 11 1995-1996 32.2 0 12 2003-2004 32.4 0 13 1981-1982 32.6 0 - 1980-1981 32.6 0 - 1978-1979 32.6 0 14 2010-2011 32.8 0 - 1955-1956 32.8 0 15 2013-2014 32.9 0 - 1968-1969 32.9 0 16 1963-1964 33.2 0 - 1957-1958 33.2 0 17 1964-1965 33.3 0 - 1961-1962 33.3 0 18 1985-1986 33.4 0 19 2000-2001 33.5 0

We needed a big Arctic high anchored over New England like we got with the snowstorm last November. The NAO trends have been moving more positive the last few days. So the SE Ridge is just a little too strong. https://www.wpc.ncep.noaa.gov/dailywxmap/index_20181115.html