Saturday, February 28, 2015

White Christmas, and cold reality

With the solstice 10 days away, snow not even a rumor.

White Christmas, and cold reality

Even with the generous frosts and the first samplings of temperatures in the the 20s the last two mornings, December remains better than 4 degrees above normal in Philadelphia.

Afternoons should be milder the next few days, until another modest chills sets in for the weekend.

But the region's first true cold snap -- which the National Weather Service defines as three consecutive days with temperatures failing to get above 35 -- is nowhere on the horizon.

The Climate Prediction Center's 6-to-10-day outlook has two-thirds of the nation on the mild side, with the east staying warm in the 8-to-14-day range.

Taking into account the near-normal October and mild November, Mark DeLisi, the climate guru at the weather service's Mount Holly office, has come up with an intriguing statistical calculation.

By his reckoning, the later that first cold snap appears, the lesser the chances for a colder-than-normal winter. Here's his analysis.

The climate center's two-week outlook suggest that the first cold snap might hold off until after Christmas.

Speaking of Christmas, the weather service has posted its annual White Christmas probability table. You will have a hard time finding a pattern. 

Using the definition of measureable snow on the ground on the morning of Dec. 25, you'll see that the region was on a White Christmas roll from 1959 through 1966, and then 31 years passed without one. 

We like to check in on the American Weather Forums, particularly on Mondays, to mine for the latest storm buzz, but the pickings today were beyond slim.

The patterns continue to argue against any prolonged spell of serious wintry weather in the near future, perhaps not until January.

All this suggest to us that the chances of a White Christmas in Philadelphia are even slimmer than usual.

Tony Wood Inquirer Weather Columnist
About this blog

Everyone talks about the weather, and here we write about it.

When we’re around and conditions warrant, we’ll keep you updated about what’s coming, but we will do our best always to discuss weather and climate developments in context and remind you that nothing in the atmosphere happens in a vacuum.

Tony Wood has been writing about the atmosphere for The Inquirer for 26 years.

Reach Tony at twood@phillynews.com.

Tony Wood Inquirer Weather Columnist
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