Wednesday, January 16, 2008

Halfway Through Winter 2007-2008

We're halfway through winter in Philadelphia and so far, so warm in these parts. Temperatures in the first half of meteorological winter have averaged 3.5 degrees above normal through yesterday, which isn't the warmest first half of winter in Philadelphia ever, but it's still somewhat toasty. Three days at or near 65 degrees around here will do that to your average temperature. With the upcoming cold snap, those warm anomalies will take a bit of a hit over the coming week but I would not be surprised if we finish January a good two to three degrees above normal.

In the snowfall game, Philadelphia is coming in dead freaking last among Mid-Atlantic cities. For all cities north of Washington, DC, Philadelphia's 1.6" total this winter comes in dead last. From the graphic above, you can see much of the area is not exactly teeming with snowfall so far this winter, with a general two to five inch accumulation along I-95 and east and more snowfall north and west. However, the I-95 corridor average through yesterday is between five inches (DC through Philly) and 6.3 inches (NYC). A three to four inch snow deficit is not significant given that 70% of our seasonal snowfall on average is yet to come. Allentown is running at normal for snowfall and Atlantic City and Scranton are running ABOVE normal this winter so far.
A quick review of the television winter forecasts shows that so far they are all doing ok, with NBC 10 and CBS 3's winter forecast generally faring pretty good in December as temperatures for the month were just above normal. A slight advantage to CBS 3 based on the 'normal' call but NBC 10 was just a degree off. January's forecast may go to NBC 10 based on the forecast of a warmer than normal January, which will likely happen. How warm it ends up, however, remains to be seen. Channel 6, as of now, has a pretty good handle on the seasonal temperatures.

My winter forecast went up in flames in December, based on my thinking that we would see a stronger cold shot that would have lasted through much of December before moderating in January. January has a shot at verifying if this cold snap in the second half of the month persists through the end of the month...despite the methodology behind January's forecast being in reverse (cold early, warm late).

Despite the doom and gloom regarding the lack of snowfall Philadelphia does receive 70% of its normal snowfall over the next eight weeks. While the first half has not been much to smile about in the snowfall department, the snow starved can at least look at that stat and take solace in the fact that their agony may be over soon. Or, worse yet, the agony could last through the rest of the winter.