Central PA Fall Discussions and Obs

[Itstrainingtime]

Congratulations Hoosier nation. What a monkey removed from their backs. 58 years in the making.

[Blizzard of 93]

0z GFS show 2 chances of snow. The first chance is Friday & then another chance early next week.

[pawatch]

Friday looks like a clipper. It’s a start.

34 degrees this morning. 

[Festus]

As I'm fond of noting, today is the earliest sunset.  It's another month or so for the latest sunrise.  The discrepancy is the difference between true solar time and the chronological time we use.

[Mount Joy Snowman]

Low of 29. Taking the kids to see Santa today up in Elizabeth Farms above Brickerville, never been before. Should be a solid winter day. Then a big game between the Packers and Bears. Go Pack! 

[ChescoWx]

While still colder than normal for early December it will still be about the best day this week to start or finish (in my case) putting up your Christmas decorations. Highs today will be well into the 30's but still at least 5 degrees below average. We again turn sharply colder tomorrow with the passage of an arctic front late tonight. Temperatures both tomorrow and Tuesday will remain below freezing. Tomorrow night looks to be our coldest night so far this early winter season with low temperatures not too far from 10 degrees. We moderate to closer to normal on Wednesday with rain shower chances increasing and then by Thursday night into Friday may see chances for some snow in at least parts of the area. We again turn very cold by next weekend.

[ChescoWx]

I have seen a lot of chatter across social media on how it doesn’t snow as much as it used to and if we don’t see significant snow by the end of December it is winter snow potential over! I have framed up some stats on some recent winters that may be why some of these folks may being influenced by some recency bias based on winters here during the past 20 years.

 

Keep in mind it is only December 7th and some spots including East Nantmeal in Chester County have already exceeded 1 inch of snow for the season – to date most spots in our area average near 2 inches of snow to today's date in a typical season. Assuming we see no more snow this month below are some snow stats for years with 1 inch or less of accumulated snow by New Year’s Eve and the final seasonal snow totals. There is for certain a correlation but enough outliers to allow for Team Snow folks to dream!

 

30 years with 1” or less of snow by December 31st

· 5 seasons ended up with above normal snowfall at +35”

· 8 seasons ended up between 60% to 85% of normal snowfall at +20”

· 7 seasons ended up between10” to 15” of snow

· 6 seasons ended with no snow to 10%

· The greatest snow season with little pre 12/31 snow was 1977-78 when 59.8” of snow fell

· The least amount of seasonal snow was 1972-1973 when no snow at all accumulated that season at Coatesville.

To put the above in greater perspective at the NWS and trained spotter locations at Coatesville 1W/2SW and East Nantmeal there have been 47 winters with greater than 35 inches of snow. In 3 decades 1900-1909 / 1910-1919 and just recently in 2010-2019 we experienced 6 winters seasons with snowfall greater than 35”. The longest stretch of no season with over 35” was the 23 straight snow seasons from 1934-35 through 1956-57 that all failed to exceed 35 inches of snow for the winter season. So far here in the 2020’s only 2020-2021 with 52.2” of snow has exceeded the 35” mark. So, if you think it doesn’t snow as much as it used to…just imagine growing up in Chester County in the 1930’s thru 1950’s! It is important to remember our last complete decade from 2010-2019 was our 3rd snowiest decade since the 1890’s with only the 1890’s and 1900-1910 averaging more snow then that last decade we just completed. If you are a believer in cyclical climate change like me I would suspect we are due for some less snowy winters.