This is a fantastic contribution to this forum!! My hat is off to Terpeast!
I agree completely that this coming winter will be an excellent test. My research into my point specific home base Enso winter influence during the past 43 years reveals that average 1.45+ Nino winters give above normal snowfall west of the BR 88% of the time. The CPC and other venues project an approximation of this anomaly for the coming winter. This is a base of support for my winter 23-24 prediction.
According to NASSA'S GISS the earth has warmed 1.9 F. since 1880 and the warming has increased since 1980. https://earthobservatory.nasa.gov/world-of-change/global-temperatures
Ironically, the 30 year period from 1945 to 1975 was slightly cooler than normal. Scientists believe that atmospheric aerosols from anthropogenic burning of fossils fuels resulted in this cooler period. Yes, from 1945-1975 we actually had anthropogenic global cooling. Passage of clean air acts in 1970 from countries around the world brought this AGC to a halt. https://skepticalscience.com/global-cooling-mid-20th-century-advanced.htm
Predicting future climate cannot be more than speculation because climate models have often been incorrect with details.
I thoroughly enjoyed digesting this excellent study. My personal take away is that from 1962 - 2015, maximum daily snow per year was largely static. The past 8 years have witnessed a steady decline of annual snowfall at this snapshot one location. My personal one location has been static with one above normal year.
I firmly believe that future winters will be variable because of many short range factors not possible to fathom more than a week or two in advance. I agree with Bob Chill along these lines.
I also believe that if the current warming continues, marginal locations and certainly D.C. is included will ultimately see more very low snowfall winters. West of the BR, not so much during the lifetime of anyone reading this.