A major snowstorm is likely this weekend for Philly, forecasters say
Snow could begin as early as Saturday afternoon, forecasters say, but, yes, it's not a done deal.
Computer models are saying with a rather uncharacteristic certainty that the Philadelphia region and much of the Midatlantic can expect a significant snowstorm during the weekend
Now, when have they ever been wrong?
On Tuesday morning, models were in general agreement that Philly had a 55% likelihood of a snowfall of at least 5 inches, the National Weather Service said, with the potential for substantially more.
Whatever does or doesn’t happen from here, the likes of Acme, Giant, Wegman’s, Whole Foods, and Trader Joe’s thank you.
“All the tools we have are starting to point toward something is going to happen,” said Mike Lee, a lead meteorologist at the weather service office in Mount Holly.
“We know it’s going to get more people uneasy, but we want people to be aware.”
Said Bob Oravec, lead forecaster with NOAA’s Weather Prediction Center, “Given the very good agreement in the numerical models, this has a very low chance of being a bust overall.”
The big commercial services, AccuWeather Inc., and the Weather Channel, also are on board.
When might snow arrive in the Philly area?
The weather service lists a 30% chance of snow Saturday afternoon, increasing to 50% at night, and 60% Sunday.
The snow would spread south to north.
In the early going, it was uncertain just which areas would receive the very heftiest amounts. Oravec said the best chances for that happening would be a stripe from northern Texas through Maryland and Delaware.
Substantial snow was less likely in areas north of the Philly region. The snow machine would be set off by dry polar air interacting with copious moisture to the south, which is likely to encounter resistance to the north.
After temperatures moderate and climb into the mid-40s Thursday, the cold air was expected to pour into the region Friday. High temperatures Saturday through Monday may struggle to get past 20, with or without a snow cover.
Is it possible that Philly will be flakeless?
Of course.
Snow forecast busts are part of the cost of doing winter business in the Philly region.
Some of the key west-to-east moving features that will power the system haven’t yet made landfall, and thus haven’t been observed by land-based instruments.
“Historically, when these features can better be identified by the weather balloon network across North America, the models forecasts improve and converge on a common solution,” said Oravec.
Oravec cautioned that while computer models are marvels and “do a great job at identifying large scale patterns that are conducive for major winter storms.”
But, “Some of the smaller details, that can enhance the impacts, are harder to model.”
Perhaps the most important data point to consider: It’s only Tuesday.