Philadelphia weather forecast has storms, cold front and migrating birds


The coldest air in more than four months will follow a cold front through the Philadelphia area on Tuesday evening, accompanied by another sure sign of fall: vast hosts of migratory birds.

The front could trigger severe storms Tuesday afternoon and evening – and the Storm Prediction Center had the area under “marginal risk” of severe weather – but “certainly not as high a risk as we’ve seen recently” , said Sarah Johnson. , chief meteorologist at the National Weather Service Office in Mount Holly.

The forecast for Wednesday was more interesting for the birdwatching community: Sunny with nearly 100% of the birds en route to their wintering grounds in South and Central and South America.

It’s the peak season for migrants, and bird watchers love cold fronts, says Keith Russell, program manager for Audubon in Pennsylvania, who described Philadelphia as a “migration center.”

One of the biggest complaints we hear from bird watchers is “Why don’t we have cold fronts? “

Brett Ewald, Director of the Cape May Observatory

Birds that have spent the summer breeding in the vast boreal forests of southern Canada and their chicks are likely to hitchhike on air waves.

“One of the biggest complaints we hear from bird watchers is ‘why don’t we have cold fronts,’ said Brett Ewald, director of the Cape May Bird Observatory. “We are always looking for the next cold front.

READ MORE: Why Bird Watchers Flock to Cape May and Philly: “We are at the heart of migration.

For migratory purposes, this particular front was obviously strategically positioned Monday night, stretching from Quebec to central Michigan, Johnson said. Along with the threat of a thunderstorm ahead of the front, after the region clears, temperatures could drop into the 1940s, even in the city, by Friday morning.

Winds will blow gently, less than 10 mph from the north and northwest, which should provide excellent flying conditions, and songbirds migrating at night, which use the stars and topography as aids to navigation, will likely make stops through Pennsylvania and New Jersey. .

Birdcast.net, affiliated with Cornell University, places the entire region in the moderate zone for migrants on Tuesday night, with 27.4 million forecast to fill the night sky across the country on the basis of radar observations which detect night take-offs.

The Cape May Observatory, rated one of the country’s top birding sites by Audubon magazine, is in a fortuitous position as these post-frontal northwest winds “push the birds to the coast,” Ewald said. It is located on a finger of land separating Delaware Bay and the Atlantic Ocean, an ideal starting point for heading south.

Bird watchers might spot a rarity like the Connecticut Warbler after a frontal passage, but in Cape May, “you should be able to find 50 species, and 100 on a good day, several hundred after a cold front” and maybe 10,000. song birds.

READ MORE: Up to 1,500 birds flew into some of Philly’s tallest skyscrapers on one day last week. The massacre shook bird watchers.

He said that after a frontal pass, “you can potentially get 3,000 to 5,000 raptors.” He recalled that a few years ago, one day in mid-October, 5,400 American Kestrals had been spotted.

The facades aren’t just travel aids, Ewald said, but they also signal the autumn chill that is starting to clear up those insect buffets that some birds are so dependent on.

Ewald warns that all fronts unfold differently and that it is not possible to accurately predict how many migrants will appear in their wake.

READ MORE: The fall equinox arrives Wednesday. Here’s what to know about it as the days of Philly get shorter before our eyes.

“You don’t know how many you’re going to see,” he said, “and how many different kinds you’re going to see. “

But if the front is strong enough, he said, “you can get several good days in a row.”


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