The snow-accumulation forecasts include a lot of wiggle room, but don't be surprised if the actual results vary even more wildely than the forecasts suggest.
We wouldn't be shocked if the totals called in by National Weather Service spotters in Philadelphia and the surrounding counties tomorrow ranged from 2 to 10 inches. And the differences won't necessarily be along the traditional lines, southeast to northwest.
At this writing, it appears that no one near Philadelphia will see significant accumulating snow during the day, and the region should skate through the afternoon commute without much trauma.
In a rather dramatic shift from this morning, the National Weather Service has issued a winter storm warning for all of Montgomery and Bucks Counties and part of Chester County for 4 to 8 inches of snow late tomorrow into Saturday.
In the immediate Philadelphia area, the call is for 3 to 5 inches, with the changeover from to snow coming later.
When the change to snow occurs, forecasters are saying the precipitation will come fast and furious, perhaps at a rate of an inch or 2 an hour.
As mentioned, the earlier forecast of 1 to 2 inches in and around Philadelphia, looked to be on the conservative side.
The National Weather Service has now upped the projected amount to 2 to 4 in the city, and 4 to 6 in some of the northern and western suburbs.
We expect some winter weather advisories and watches to go up with the afternoon forecast packages.
While we wait for computer models to resolve their differences on the coming storm -- and for the atmopshere to have the last laugh -- we note that Philadelphia evidently is approaching a snow record.
Officially, a trace of snow was detected yesterday at Philadelphia International Airport, the seventh straight day snowflakes have been observed.
Not that the shovels and plows are getting a workout. The official total for the entire seven days stands at 1.2 inches, the seasonal total at an anemic 5.4.
For days the European forecast model has foreseen a potent winter storm forming off the Atlantic coast, and now the short-term models are in accord.
This is likely to be a volatile and fluid situation, and expect forecast changes while the storm is raging.
The current National Weather Service forecast is calling for the storm to begin affecting the region Thursday night and to linger well into Saturday.
For the sixth consecutive day, snowflakes are showing up in the region as showers are moving from the south and west toward Philadelphia.
As noted, this has been the season of the penny snow, and this would be no exception, with no more than a half-inch expected.
This episode could be a bit more troublesome than its predecessors, however, since the showers are coinciding with the peak commuting period.
Incredibly, measureable snow has fallen on four consecutive days in Philadelphia, and later on this is likely to become the fifth.
Yet the grand total for the entire season at Philadelphia International Airport/National Park stands at 5.1 inches.
Most winters have their dominant characteristics, and as Gary Szatkowski at the National Weather Service in Mount Holly noted, this has been the season of the one-penny and two-penny snows.
That drive-by clipper picked up some last-minute juice from the ocean and gave towns in Cape May county their biggest snow hit of the season.
The National Weather Service spotter in Seaville weighed in with 7.5 inches; other towns in the neighborhood, and Dover, Del, ended up in the 6-inch rain
Dennisville, Seaville, and Woodbine spotters all weighed in with 6 inches, with 5.9 at Dover. Here's the latest accumulation list.
Taken together, the last two winters have a shot at joining elite company. Among back-to-back mild winters, they are on pace to become among the warmest tandems on record.
The two-season average temperatures are running at just over 40 degrees.
The all-time two winter champs are those legendary seasons of 1931-32, and 1932-33, at 41.6, and 40.1 respectively.
A drive-by Alberta Clippper is generating decent snows at the Shore, and a fairly intense snow-burst is coating the ground around Philly.
The system has been moisture-starved, but has picked up some juice at the last minute as it approaches the Atlantic.
It should all be over in an hour or so, but already 2 inches has been reported in Cape May, and Philadelphia is likely to add a few more tenths to its paltry seasonal snow total.
Tony Wood has been writing about the atmosphere for The Inquirer for 26 years. E-mail Tony here. And read all his columns here.
