bluewave

I remember that day very well. The forecast was for snow to quickly change to rain. Got on the Meadowbrook Parkway around 1pm near Garden City with heavy thundersnow. The traffic backup was so bad that I had to take Merrick Ave south instead. Then had to stop every few minutes to clean the windshield off by hand since the wipers couldn’t keep up. Had Craig Allen on the AM radio the whole time for updates. They had to get him on the air earlier than usual due to the surprise nature of the storm. What was usually a 30 minute drive for me took 4 hours to get back to Long Beach with around 10”.

We have actually have done much better with snowfall from late October in to mid-November since 2010 than in late November. 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 28 to Nov 20 Missing Count 2022-11-20 0.0 0 2021-11-20 T 0 2020-11-20 0.0 0 2019-11-20 0.0 0 2018-11-20 6.4 0 2017-11-20 T 0 2016-11-20 T 0 2015-11-20 0.0 0 2014-11-20 T 0 2013-11-20 T 0 2012-11-20 4.7 0 2011-11-20 2.9 0 2010-11-20 T 0 Time Series Summary for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Ending Date Total Snowfall Nov 21 to Nov 30 Missing Count 2022-11-30 0.0 0 2021-11-30 T 0 2020-11-30 0.0 0 2019-11-30 0.0 0 2018-11-30 T 0 2017-11-30 0.0 0 2016-11-30 0.0 0 2015-11-30 0.0 0 2014-11-30 0.2 0 2013-11-30 T 0 2012-11-30 T 0 2011-11-30 0.0 0 2010-11-30 0.0 0

Yeah, the model graphics off of the old Alden Difax machines were primitive compared to what we have today. Plus the accuracy of those old models was so low that it was the era of nowcasting many big events. I can remember all the paper jams in those old machines. But the April 1982 blizzard still stands as one of my favorite snowstorms of all time. Starting as rain and then changing to blizzard conditions with some of the most lightning I have ever seen with snow. To have early April heavy snow stick on the pavement in the afternoon with no trouble after rain with highs only in the 20s was like something out of the 1800s.

The 80s were known for the big 3. Historic April 82 blizzard that still stands as our greatest late season blizzard. The famous February 83 snowstorm. Then the surprise January 87 snowstorm that was supposed to quickly change to rain but dropped near 10” on Long Island. You could also add the surprise December 88 Norlun that dropped around 10” on Long Island. But the snow band was so narrow that Western Suffolk had close to 12” and Long Beach got nothing. So it was too limited in coverage for me to add to my big 3 list.

Rainy and windy GL cutter next Tuesday into Wednesday will pull down colder air for late November with the first freeze in NYC likely.

While this spike may very well be temporary, the reason behind it is open to debate. May not be exclusively related to El Niño in a way that we traditionally understand. This El Niño is much weaker than 15-16. El Nino global temperatures typically peak near the end of the event in the late winter like in February 2016. This summer into fall historic spike is going against that previous pattern.

We have seen convection return to the Maritime Continent in the past following strong IODs once the IOD dropped to moderate +1 to +1.5 range. The WPAC warm pool is an enormous heat engine. The area of cooling near Java usually bounces back pretty quickly once the IOD drops below +1.

With the rapidly fading +IOD, it will be important how quickly we get a MJO 4-6 forcing rebound in December. The current GEFS and EPS have some forcing returning to the Maritime Continent in early December. We definitely want to see that muted or uncoupled.

My interest in recent years has being trying to figure out why some periods like December into January 20-21 and January 22 went so strongly against the La Niña -PDO background state. These patterns usually sneak up on the short term models for a welcome surprise like they started to do in late November 20. Plus many of these more +PDO atmospheric patterns have actually occurred in the warm season and have lead to record heat and drought out West. But the last time we had such a wall to wall pattern like that in the cold season was the 14-15 winter.

Humans are an extremely adaptable species. So even if the most severe climate scenarios play out, we will find a way to survive. But other species may not be as fortunate. That being said, most of the carbon emissions are now occurring in places like China. The US has actually slightly decreased emissions. Outside of technological innovations on our part, we don’t have any say in how other countries like China manage their emissions. So while our economies are still depended too on fossil fuels, we need to find innovations to adapt to a warming climate. It’s probably going to be a slow energy transition and my guess is that we are probably on track for at least +2C to +3C of warming since the industrial revolution. And possibly beyond that if we don’t start moving faster to find a technologies to transition between 2030 and 2050.

Ultimately, it’s what the atmospheric component of the PDO is doing at any given time which is more important. By atmospheric component I mean the 500 mb pattern. Last winter the oceanic -PDO was strongly aligned with the 500 mb atmospheric component. So the end result was a La Niña on steroids pattern. For some reason, the 500 mb pattern in early 20-21 and Jan 22 was more +PDO +PNA than the oceanic strong -PDO was indicating. So the alignment issue is very important for our sensible weather. Even though the oceanic PDO signature is currently negative, the recent forecast for late November is classic +PDO with the -EPO +PNA. We want to see this more +PDO atmospheric pattern continue. Unfortunately, forecasting when these deviations from the oceanic index will occur usually comes down to the shorter range models.

Yeah, 2017 was one of the few Decembers since 2011 that was cold in the Northeast. The one common denominator with Decembers in the Northeast since 2011 has been warmth regardless of El Niño or La Niña. https://www.ncei.noaa.gov/access/monitoring/climate-at-a-glance/regional/time-series/101/tavg/1/12/1895-2023?base_prd=true&begbaseyear=1981&endbaseyear=2010 December 2022…30.2….+1.2….La Niña -PDO 2021….33.5….+4.5….La Niña -PDO…4th warmest on record 2020…30.9…..+3.2….La Niña -PDO…17th warmest 2019….29.0…..+1.3….Neutral 2018….29.3….+1.6…..Uncoupled El Niño -PDO 2017….24.2….-3.5….La Niña Neutral PDO 2016….28.3….+0.6…La Niña +PDO 2015….39.4…..+11.7….Super El Niño +PDO record MJO 4-6 warmest December on record by a wide margin. 2014….31.6…..+3.9….Modoki El Niño +PDO 14th warmest on record 2013….26.1….-1.1….Neutral 2012….32.4…..+4.7…El Nino peaked on Labor Day and went neutral with a -PDO….winter followed backloaded El Niño theme with Nemo in February 2011…32.7….+5.0…..La Niña -PDO….8th warmest December

More of a moderate WWB compared to some of the stronger November WWBs in years past.

November has been the only fall month with record lows around NYC since the super El Niño. But 17-18 was a much better winter into March than 19-20. New York-Central Park Area, NYPeriod of record: 1869-01-01 through 2023-11-13DateLowest minimum temperatures (degrees F) 11/8 29 in 2019 29 in 1886 30 in 1992+ 11/9 24 in 1976 27 in 2019 28 in 1971 11/10 25 in 2017 27 in 1914 29 in 2004+ 11/11 24 in 2017 28 in 1933 28 in 1926+ 11/12 25 in 2019 26 in 1926 27 in 1920 11/13 23 in 2019 24 in 1986 25 in 1920

October was an impressive peak for the IOD with the huge reduction in cloud cover over the Eastern IO.

The IOD peaked back in October. http://www.bom.gov.au/climate/enso/indices.shtml#bookmark=nino3.4

We’ll probably need the northern stream to relax otherwise any southern stream systems coming after Thanksgiving run the risk of suppression like we are seeing in the forecasts for this weekend. Looks like plenty of Canadian high pressure dominating after Thanksgiving with the -EPO+PNA.

Hopefully, the cold front clears the area and we get a dry Thanksgiving for travel. The EPS may be holding too much energy back to the SW. The GEFS and GEPS have rain on Wednesday but clearing out and cooler for Thanksgiving. Looks like a brief warm up ahead of the cold front.

While OISST hasn’t updated in a while, CRW may have already peaked. This would fit the pattern of El Niños typically peaking by November. It would also mark another year since 2012 with El Niño forecasts showing a significant warm bias. It’s probably related to the models not being able to handle the destructive interference from the record WPAC warm pool and persistent -PDO.

Yeah, looks like our typical post 2010 fall around the region. Endless summer into September or October followed by colder departures in November. This has become very predictable.

All we can say is the warm up around the solstice is a feature of our new climate. The rate of warming since 1981 in late December has been increasing a a significantly faster rate than early December. So our average near 40° is similar to the average in early December 40 years ago. So going over 55 during this period from a week before to around Christmas is the new normal.

These kind of run to run jumps don’t inspire a lot of confidence. The split flow is taking its toll on the EPS. Just give me a clean pattern without competing influences.

Yeah, always weary to buy into Euro phases when it can be over amped at times. I would love to see some phases with the southern stream. It would tell us that the northern stream isn’t as overpowering as recent years. But the southern stream has been getting suppressed in these split flow patterns. We need a change from the cutter hugger, and southern stream suppression storm tracks. Bring back that epic benchmark pattern from 2013 to 2018.

I am thinking we would need a full phase to draw down enough cold air behind that system for a freeze in NYC. Models like the ICON and GFS keep the streams slightly separate. So no freeze in NYC.

The models are really struggling with the split flow and it may be a while before they get the pattern correct. La Niña background lingering through -PDO and El Nino southern stream trying to assert itself. So probably a different solution each run next several days. Models don’t handle competing influences very well.