*** Paul Piorek is editor and publisher of Paul's Local Weather Journal for southwestern Connecticut ... Paul is the on-air meteorologist at WICC 600 AM and 107.3 FM ... Paul is a New York Emmy award winner (2007), five-time Emmy nominee, and four-time winner of the Connecticut Associated Press Broadcasters' Association award for Best TV Weathercast (2006, 2008, 2009, 2012) ... Paul was voted Best Local Television Personality by the readers of Fairfield County Weekly Magazine (2012) ... Paul was inducted into the Housatonic Community College Hall of Fame and received the Distinguished Alumni Award (2012) ... The local weather journal is a two-time winner of the Communicator Award of Distinction (2012 & 2013) ... Paul is currently a full-time teacher of Earth Science and Mathematics in Fairfield ... Follow Paul on Twitter @PaulPiorekWICC ...

Tuesday, December 13, 2011

The Odds of a White Christmas

This morning featured some of the coldest temperatures of the season. The mercury dropped into the teens inland and low-to-mid 20s just before daybreak, and a coating of frost caused car windshields, lawns, and rooftops to glisten from the light of the waning Moon.

Christmas is less than two weeks away, and many people have asked me about the odds of seeing a "White Christmas." Other than the historic Nor'easter the last weekend of October, we haven't seen any snow the last two months. Although showers are expected this Thursday and an offshore storm should stay far enough away early this weekend, there aren't any snowstorms in sight. I am watching the potential for a possible Wintry mix next Tuesday, however.

So, what are the chances of snow by Christmas? Here in southwestern Connecticut, weather records have been kept for a long time. Our climatology is based on record-keeping over a 40-year period. Based on history, shoreline communities such as Stamford, Darien, Stratford, and Milford have a 30% chance of seeing at least one inch of snow on the ground by December 25. There's a 10% chance of at least five inches of snow on the ground by then. However, we have a zero percent probability of having ten inches of snow or more on our front lawns by Christmas morning.

Bing

Inland, the odds are more favorable. People living north of the Merritt or Wilbur Cross parkways have a 57% chance of at least one inch of snow for Christmas. The odds are slightly lower than one-in-four (23%) for five inches of snow, and quite slim (3%) for at least ten inches of snow. However, residents in Wilton, Redding, Easton, and Woodbridge have a much better opportunity of seeing snow on the ground than their shoreline counterparts.

As far as the rest of New England is concerned, the chance of a white Christmas gets even better. Northern Connecticut and southern Massachusetts have about a 40 to 60% chance of at least one inch of snow; central New England's chances improve to 60 to 80 percent; and northern New England (80 to 100%) is virtualy assured of having a White Christmas.

One of the more memorable snowstorms which occured in late December was the Christmas Eve storm of 1966. We received over a half-foot of snow (6.9"), making roads quite slippery and travel very difficult. I distinctly remember my family on our way to visit my grandmother in the snow, but my parents deciding the drive wasn't worth the risk. We turned around and headed for home, but the car slid several times on the snowy roadways.

You may recall the snowstorm which delivered more than nine inches of snow to southwestern Connecticut the weekend of December 19 and 20, 2009. The snow began late Saturday evening, and six inches had accumulated by midnight. The snow tapered off early Sunday morning, but not before another 3.2 inches caused headaches for holiday shoppers the last weekend before Christmas.

Another recent snow occurred on Christmas Day, 2002. Some light snow happened early that morning, but a steadier and heavier snow developed by later in the afternoon and evening. The snow totals were quite impressive locally. Darien received 10 inches of snow by the time the storm exited the following day. Redding (9.5"), New Canaan (9.2"), Norwalk (7.0"), Greenwich (7.0"), and Westport (6.5") each saw at least a half-foot of snow!

On the flip side, I'm sure you recall December of  2006. The afternoon high temperatures from December 23 to 26 reached 58, 52, 44, and 50 degrees respectively, well above the 38-degree normal high. Over an inch of rain fell December 23 (1.15") and over a quarter-inch (0.28") was recorded on Christmas Day. We were left dreaming of snow for quite some time.

Paul