Manni said:
"Yes! The first snowfall of the year" - someone, somewhere at least once a day
Is this statement true?
My first thought was that the title of the thread (The First Snow Fall of the Season) is very different from the question posed in the original post.
My second thought was that the question was a math/logic riddle posed as a climatological question. Something about continuity and a branch cut at midnight on January first? Nah.
My third thought was that the question posed in the original post is a bit ill-formed. Assuming the key is "year" rather than "season", I see four distinct interpretations. My second thought suggests a mathy rather than riddle-like expression. My interpretations are:
- For every year and for every day of the year, there exists some location on the Earth at which the first snowfall of that year fell on that day at that location.
- There exists some year such for every day of the year, there exists some location on the Earth at which the first snowfall of that year fell on that day at that location.
- For every day of the year, there exists some year such that there exists some location on the Earth at which the first snowfall of that year fell on that day at that location.
- None of the above.
Interpretation #4 is a catch-all in case I'm way off the mark. I'll ignore that interpretation, but am willing to stand corrected. Interpretation #1 involves two universal quantifiers and is the hardest to answer in the affirmative. Interpretation #2 changes the universal quantifier on the year to an existential quantifier; one flukey year is all it takes to say the answer is true. Interpretation #3 is weaker still.
One key to the problem is the branch cut at midnight on January first. Suppose a winter storm in the southern hemisphere brings the first snow of the season on June 30th in some areas, July 1st in others. That first snow of the season was most likely the first snow of the year as well.
Now look at the northern hemisphere, where the corresponding winter storm would bring the first snow of the season on December 31st in some areas, January 1st in others. While the January 1st snowfall was obviously the first snowfall of the year, the December 31st snowfall was the last snowfall of the year. That last snowfall of the year was the first snowfall of the year only if the area had not received any snow whatsoever for the 364 preceding days (365 preceding days in the case of a leap year).
While the first snowfall of the year occurring on June 30th is not at all problematic, the first snowfall of the year occurring on December 31st is a bit problematic. The branch cut at midnight on January first means that the key to answering in the negative lies in the northern hemisphere. There's no support from the southern hemisphere to make December 31st the first snowfall of the year. December 31st is well into climatological summer in the southern hemisphere. December 31st is not the answer, however. A place where it snows rather infrequently may well see a snowless winter followed a year later by a fluke New Year's Eve snow storm.
The key to the problem is late October / early November. Early climatological autumn in the northern hemisphere is early climatological spring in the northern hemisphere. Some place in the southern hemisphere that receives snow infrequently may well be hit by an early spring snowstorm that brings the first snow of the year. Support for first snowfall of the year occurring in climatological spring somewhere in the southern hemisphere dwindles as spring starts turning to summer. Places in the southern hemisphere that do experience snowfall in late October / early November almost certainly receive snow in June, July, and August. In the northern hemisphere, places that experience snowfall in late October / early November almost certainly experience snowfall in January, February, and March.
I would say that the answer is almost certainly no to interpretation #1, possibly yes to interpretation #3.