Updraft: December 13, 2007 Archive

Brighter days ahead

Posted at 7:15 AM on December 13, 2007 by Paul Huttner

I love December 16th.

That's the day when our sunset starts getting later. When you're a weather geek like me, you notice these kinds of things. Yes, I read the sunrise and sunset calendars, sometimes plan my vacation by the moon phases, and I'm a real hoot at cocktail parties.

You might think the earliest sunset and latest sunrise would come on the winter solstice, which occurs this year at 12:08am on Saturday December 22nd. But due to a quirk in the earth's orbit and axis, sunset starts getting later on December 16th, and sunrise occurs earlier until after the solstice. Total daylight balances out on December 22nd, the shortest daylight of the year. Then the overall daylight begins to increase.

Earth's orbital quirks explained

December solar data fro the Twin Cities

So if you're like me you'll celebrate this Sunday December 16th. I'm up before sunrise most days, but I'm still a sunset kind of guy. Call me a desperate Minnesotan, but I'll grab on to any glimmer of hope I can this time of the year!

PH

Historical probabilites of a White Christmas in the MPR network

Posted at 11:16 AM on December 13, 2007 by Mark Seeley

As we anticipate some moderation in temperatures the week before Christmas, we may lose some of the regional snow cover. Still it looks like most within the range of MPR broadcasts will likely see a White Christmas.

The National Climatic Data Center provides a data base showing the historical probabilities for a White Christmas, defined as at least 1 inch of snow cover on December 25th. The probability of a White Christmas for some of the specific MPR network stations can be calculated from this data base: Each is shown below:

KNCM (88.5FM)-Appleton 60% KNBJ (91.3FM)-Bemidji 85%
KNOW (91.1FM)-Twin Cities 75% KNBJ (88.1FM)-International Falls 100%
KLNI (88.7FM)-Decorah, IA 55% WSCN (100.5FM)-Duluth/Superior 100%
KXLC (91.1FM)-La Cresecent/La Crosse 70% KCCD (90.3FM)-Moorhead 80%
KZSE (90.7FM)-Rochester 65% KNSR (88.9FM)-St Cloud/Collegeville 75%
KNGA (91.5FM)-St Peter/Mankato 70% KNTN (102.7FM)-Thief River Falls 85%
WIRN (92.5)-Virginia/Hibbing 95% KNSW (91.7FM)-Worthington/Marshall 75%
WLSN (89.7FM)-Grand Marais 100% WGGL (91.1FM)-Houghton, MI 100%

Speaking of White Christmas, some of our cultural values and expectations, whether weather-related or not, have evolved from religious beliefs and some from secular traditions. These are detailed in a new book by Bruce Forbes called "Christmas: A Candid History"...I highly recommend this book if you are interested in the history of this holiday.