Saturday, December 22, 2012

Updating The Chase For Warmest Decembers

If December were a 21 day month, our average monthly temperature of 46.0 degrees would be the warmest in Philadelphia since 2001's 48.4 degree mark for the first three weeks of December.   Thankfully it's not and thankfully for cold lovers the next 10 days will provide a decent appetizer of more typical December weather into the Delaware Valley.  Not arctic cold, not even near arctic cold, but it's a reminder that winter does exist after a three week hiatus.

Warmest Decembers and subsequent winters -- including the "average" December  since 1981.

Looking at probable temperatures between now and month's end and Philadelphia will likely finish between 43.5 and 44.0 for a monthly average temperature this December.  For a final rank, that would place it either 3rd, 4th, or 5th in terms of warmest on record.  While this December may be warmer in the end than 2011, believe it or not, the resulting winter for us will probably end up better in comparison as cold and snow chances do look a bit more bountiful over the coming several weeks around here, which was in contrast to last winter when such cold and snow chances really didn't exist.

In warm Decembers such as this one, the winter "shockingly" (sarcasm intend) is warm as well although we have seen some rather stark swings of the pendulum over the course of winter.  One recent example of this was 2006-2007, which featured an insanely mild stretch of December and early January; you might remember those 70 degree days in December and January that winter before winter really arrived around mid January.  Well, after one of the warmest first halves of winter on record Philadelphia entered a ten week stretch of wild, icy weather that included our coldest month to normal since December 1989 in February 2007's near seven degree departure.  Winter can come back with a vengeance some years.  While none of the winters were big snow producers, a couple of winters ended up fairing pretty close to normal on snowfall for the winter.

This winter may not be like the 09-10 and 10-11 superwinters for snow and cold but with an active pattern forthcoming over the next two weeks the odds for some snow definitely exist.  It may not be as much as some snowstarved folks want but it's better than not having any chance at all.