the december 5th coincidence

[Ian]

http://voices.washingtonpost.com/capitalweathergang/2010/12/the_december_5_coincidence.html

[usedtobe]

http://voices.washin...oincidence.html

Nice article. I took you're data from the table and entered it into a spreadsheet and started to do a running mean to smooth out all the bumps but have gotten sidetracked.

[AfewUniversesBelowNormal]

With so many unknown variables associated with weather, I don't think anything can be labeled as coincidence. Why has the NAO tanked in mid to late October almost every year since 2002? Why was almost every January from 1998 to 2008 very warm across the US? Why have most July's since 1998 had the same temperature look? There are many more recent and past examples of history repeating on the same calender dates over a 10-15 year period, mostly paralleling decadal PDO and AMO shifts. Is this coincidence, or something more at work? Although it's hard to pinpoint an exact source, I'd lean toward the second option. When late November/early December is cold and -NAO year after year, it makes sense that December 5th would have an increased likelihood of snow.

[Ian]

Nice article. I took you're data from the table and entered it into a spreadsheet and started to do a running mean to smooth out all the bumps but have gotten sidetracked.

cool, i'd like to see that when done. though, note the graph in this post is different than the data you have... that included back to 1884, in this i only included 1888 on since that's the accepted historical record. if you want the updated numbers let me know.

[Ian]

With so many unknown variables associated with weather, I don't think anything can be labeled as coincidence. Why has the NAO tanked in mid to late October almost every year since 2002? Why was almost every January from 1998 to 2008 very warm across the US? Why have most July's since 1998 had the same temperature look? There are many more recent and past examples of history repeating on the same calender dates over a 10-15 year period, mostly paralleling decadal PDO and AMO shifts. Is this coincidence, or something more at work? Although it's hard to pinpoint an exact source, I'd lean toward the second option. When late November/early December is cold and -NAO year after year, it makes sense that December 5th would have an increased likelihood of snow.

you're probably right that it is not total coincidence. i was going to reframe it that way but i tried to match it to what we put in the book as much as possible.. and the book is kinda dumbed down as much as possible.

[usedtobe]

cool, i'd like to see that when done. though, note the graph in this post is different than the data you have... that included back to 1884, in this i only included 1888 on since that's the accepted historical record. if you want the updated numbers let me know.

I think I want to do that. I'e been giving out slightly wrong stats for snow thinking the period was 122 years.

[Ian]

I think I want to do that. I'e been giving out slightly wrong stats for snow thinking the period was 122 years.

sorry about that if it was confusing... i sorta started pulling the numbers then got sidetracked since so never really finished it. i didnt even think about it including numbers not in the record till i was doing this post.

i will shoot you an e-mail with the update in a spreadsheet.

[usedtobe]

sorry about that if it was confusing... i sorta started pulling the numbers then got sidetracked since so never really finished it. i didnt even think about it including numbers not in the record till i was doing this post.

i will shoot you an e-mail with the update in a spreadsheet.

I'd appreciate it.

[Avdave]

I dont think this Dec 5th will have any snow

Pattern is broken

[RodneyS]

I dont think this Dec 5th will have any snow

Pattern is broken

As I posted in mid-September on the other December 5th thread:

"I love coincidences, but what is the meteorological basis for believing that something has changed with respect to December 5th in DC? I note that, had we been doing this type of analysis in the mid 1960's, we likely would have focused not on December 5th, but rather on December 11th. It snowed that day in DC in 1957 (0.6 inches), 1958 (trace), 1960 (6.8 inches), 1962 (1.8 inches), and 1963 (trace). Since then, however, there has been no measurable snow in DC on that day, and even a trace has fallen only in 1973, 1986, 1988, 1992, and 2004." See http://www.americanw...h/#entry1747736

[winterymix]

Good thread about strong weather coincidences.

When I was in "junior high school", sometime between 1966 and 1970, we enjoyed a winter with accumulating snow on each and every Wednesday for nearly two months. Wish I could remember which year it was, the location was Baltimore County.

[Ian]

Good thread about strong weather coincidences.

When I was in "junior high school", sometime between 1966 and 1970, we enjoyed a winter with accumulating snow on each and every Wednesday for nearly two months. Wish I could remember which year it was, the location was Baltimore County.

that sorta seems to be something we see quite often... an event around the same time or at the same time about every week or so in an active pattern.

[Cobalt]

RIP Dec 5th coincidence. Let it be a relic of the past

[PrinceFrederickWx]

Forget Dec. 5 - the new one is President's weekend (Saturday- Monday). If we get snow this weekend that'll be three of the last four years that had measurable snow. Although this time period makes more sense with peak climo than Dec. 5 does.