bluewave

The comparison is valid since the Saranac Lake area has warmed +5.2° since 1991 in late December between 17th and 31st. NYC is up +4.6° over the same period. Many areas have experienced a steep rise in late December temperatures. Its another one of the repeating patterns which have become a regular occurrence as the climate has warmed.

The snowfall data below is what I post each December for La Niña conditions using the newer RONI definition due to the warming of the global oceans. The December to seasonal snowfall relationship has worked 14 out of the last 15 times. My guess is the reason for the reliability as an early seasonal marker for below and normal to above average snowfall across the entire season is related to the La Niña seasonal progression. They tend to be more frontloaded in nature so their seasonal snowfall pattern is usually revealed early on in December. Plus in our warmer climate we have been noticing more repeating patterns perhaps related to non linear convective thresholds being met in tropical oceans driving the forcing. The relationship holds for NYC, EWR, and LGA. I will post the data for NYC below which is similar to the other two stations. For the sake of this discussion I have been using 4” of snow in December as the cutoff. But it’s possible that it could actually be a little higher around 5” inches based on the available data. So it’s fine if someone else wants to use a 4-5” snowfall range for December snowfall as the cutoff line for below and normal to above normal seasonal snowfall. I am not making the argument that the December snowfall is causing the outcome of the rest of the season to change. Just that it serves as a marker of what expect the rest of the season. Sometimes two data points can be related due to other underlying variables that may not yet be fully sampled by our current scientific understanding. I will update this post once we have the complete December snowfall data. NYC December to seasonal snowfall during the most recent 15 La Niña seasons as defined by RONI in either the fall into winter https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt 24-25….2.8”….12.9” 22-23….T……….2.3” 21-22…..0.2”……17.9” 20-21…..10.5”….38.6” 17-18……7.7”……40.9” 16-17……3.2”……30.2” the one case in the last 30 years that didn’t work out 11-12……0.0”…..7.4” 10-11…..20.1”…..61.9” 08-09…..6.0”…..27.6” 07-08……2.9”…..11.9” 05-06…..9.7”…..40.0” 00-01…..13.4”…..35.0” 99-00…..T……….16.3” 98-99……2.0”…..12.7” 95-96…..11.5”……75.6”

Yeah, the 100-200 year blocking event that winter as per some of the historical reconstructions was just too strong for the 75”+seasonal totals to our south to make it up to the NYC Metro era. A little weaker on the blocking and NYC could have approached the 1995-1996 all-time record. Same went for 2010-2011 which could have challenged the 75” mark around NYC had the snowy pattern persisted into February and March.

2015-2016 was a super El Niño like 1982-1983 and both years had blockbuster snowstorms during the 2nd half of winter. This was the case since El Niños usually start out slow snd have their snowiest periods later. So we often can’t use December El Niños as a marker for the rest of the season. But sometimes in the cases like 2002-2003 and 2009-2010 El Niños, December is so snowy that we get epic follow up snows during the February El Niño prime time. So in those cases a December forecast for a very snowy season would have worked out.

The relationship has worked out over 90% of the time for the last 15 La Ninas since the 1990s. But this doesn’t mean that it’s guaranteed to be a solid 100% for every single La Niña we continue to have. Just that it can be used a a reliable marker most La Niña years as to whether we can expect above or below average seasonal snowfall based on what happens in December.

This is broad-brushing on your part since we are discussing a particular subset of Decembers that are based on La Niña which has been more recently defined by RONI as the global oceans have rapidly been warming. La Nina’s historically have been defined by an early start to winter relative to El Niños. This is why you see frequent references to frontloaded and backloaded winters. So it makes it easier for us to use a December as a marker for the rest of the season due to the nature of La Ninas.

Well it sounded like from the tone of your posts that is what you were questioning. Bx Engine is a hard working guy and I don’t want to tie up his valuable time with disputes that didn’t exist then. Unfortunately, sometimes it’s hard to read intentions on an online forum when you aren’t meeting face to face with someone.

I was talking about the fact that repeating patterns have become more pronounced as the climate has warmed. While there was a weaker December to seasonal snowfall relationship prior to the 1990s, it has become more pronounced. My theory as to why this is that case is that we are seeing the beginnings of non-linear climate shifts. As convective thresholds begin to be crossed in tropical forcing regions with rapidly warming SSTs, it can be like flipping a switch where patterns start locking in more and become more persistent. Now the paper below is very technical, but in a tangential way to our discussion it’s the beginning of some new and potentially promising research. Circus Tents, Convective Thresholds, and the Non-Linear Climate Response to Tropical SSTs https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022GL101499

The data has been widely posted here by myself and other posters. This isn’t some new and controversial revelation. It’s just one of the many new repeating patterns which have become more pronounced as our climate has rapidly warmed. I suspect we are seeing non-linear shifts which make them so persistent.

The heaviest with that event went just south of the NYC to LGA corridor so the lack of a 4” daily measurement in those locations made sense since it was such a narrow band.

They have been posted extensively here which is more than I can say about your data.

You seem to dip into these threads to try to stir up controversy and add snarky comments rather than add to value to the ongoing discussions.

All I know about you is you occasional posts in here mostly early in the winter making bold claims and then you do not come back when they don’t work out.

LGA is in the same boat. We are talking about daily measurements and not storm totals spanning multiple days. No one said that they were. Just that we don’t get as much snow from them regularly as we used to.

Then your methodology is off.