Those surprisingly robust rains that triggered flood warnings for areas along the Wissahickon Creek in Philadelphia and Montgomery County and the Nehsaminy Creek in Bucks County set daily precipitation records Wednesday.
Flooding also was reported in West Chester and along Route 401 in Chester County, and on University City and rains continued into the night, followed by dense fog overnight that reduced visibilities to a a half-mile at times.
After a brooding, mostly overcast day Thursday, more showers are possible Friday, and then winds could howl past 40 mph in the afternoon.
And while whoever said that every cloud has a silver lining obviously wasn’t a trained sky observer, the sun is due to reappear Friday afternoon and temperatures will make a run at 80. And since they are the enemies of pollen flight, the rains should offer at least a sliver of silver to those already contending with early season tree-pollen allergies.
Officially, 1.56 inches of rain was measured officially at Philadelphia International Airport, well exceeding the 1.24 that fell on March 24, 1989. Daily records also were set in Atlantic City and Reading.
Up to 2 inches of rain had fallen in areas along the Wissahickon, and yes, these amounts weren’t quite expected, said Patrick O’Hara, a meteorologist with the National Weather Service office in Mount Holly.
On Tuesday afternoon, the weather service was calling for maybe up to a half-inch of rain, and as of Wednesday morning, no flood watches or advisories had been posted.
A coastal low off Virginia interacting with another system turned out to be a tad juicier than expected. “It’s beefier,” O’Hara said. “A few days ago the computer models weren’t showing much.”
In a month that featured the longest March dry spell in 34 years, measurable rain has fallen only three days, but with Wednesday’s downpours, totals for the month now is near long-term normals.
The flooding might have been more consequential were it not for that earlier dryness, which also probably gave a boost to the nascent pollen season.
The season, which peaks later in the spring, is off to a decent start, based on counts earlier in the week in the Midatlantic region. “I think it’s pretty close to schedule,” said Timothy Craig, a professor of medicine and pediatrics in allergy and immunology at Penn State.
Rain and moisture tend to tamp down pollen flight, as opposed to the dry air that promote ideal commuting conditions for the pollen grains that can induce rounds of sneezing, itchy eyes, and assorted discomforts among allergy victims.
So for now, they should be getting a break. In addition to showers Friday morning, more are likely Sunday.