The Ultimate Philly Weather Forecast

Think the weather we’ve seen in the last couple of years has been crazy? In the next few decades, Philadelphia could transform from a Northern city into what feels like a Southern one. And that could change everything about who we are.


One recent morning I stood near the intersection of Columbus Boulevard and Christian Street, overlooking the brown-blue Delaware, trying to imagine how the river would feel if I were wading through it with the water up to my chest, its fetid smell wafting up into my nose.

What planted that image in my head was a conversation I’d had the day before with Joe Miketta, a meteorologist with the National Weather Service in Mount Holly. Miketta—an affable guy who seems as amazed by the recent spate of weather as the rest of us—told me that we actually dodged a fairly large bullet last August with Tropical Storm Irene. Now, if you’re like my friend Michael, who lives in Lambertville and had Irene dump six feet of water into his basement, you’re probably not thinking we dodged much of anything. But Miketta told me that if the storm had arrived a few hours earlier or later, the damage could have been far worse.

The issue, he explained, was the level of the Delaware. When Irene came up the coast, she caused a surge in the Atlantic, which caused a surge in the Delaware Bay, which eventually caused a surge in the river. The break we caught was that Irene arrived in Philadelphia when the portion of the Delaware nearest the city was at a higher­-than-normal low tide, rather than what would have been an extremely high high tide. If the timing had been different—just three or four hours either way—the river­ could easily have spilled even further over its banks. Gazing across Columbus Boulevard at neighborhoods like Bella Vista and Queen Village and Society Hill, I can’t help thinking one thing: Goodbye, Philadelphia. Hello, New Orleans.

Okay, that may be a bit alarmist, but the Irene example gets at two big aquatic challenges facing Philly and the Shore in the decades ahead: the rising level of the ocean, and the vast amount of rain we could get from future Irenes and Lees (when we’re not in the middle of insidious droughts).

On the second issue, despite Joe Miketta’s warning, Philly might be in better shape than most American cities. As he sits in his office one recent afternoon, Howard Neukrug, a bearish man who’s been a longtime official in the city’s water department and who became water commissioner last winter, explains to me that there are basically two different ways to handle the kind of rain we could see in future years. One is to build bigger sewers for all that storm water to flow into; the other is to reduce the amount of storm water that flows into the sewers in the first place.

Weather machine? I’m thinking. But no, Neukrug says the second solution—the one Philly is choosing to follow because it’s ultimately less expensive and more effective than making the sewer system bigger—is to green the city as much as possible, so more water gets absorbed into the ground. The innovative program Neukrug and his team have developed to do that—a $2 billion, 25-year initiative called Green City, Clean Waters—will result in the development of all sorts of green stuff in Philly: planters and trees along our streets, porous pavement to let storm water soak through sidewalks, green parking lots, more open green spaces. In addition to helping to prevent flooding, the program, which is the most aggressive green infrastructure program in the United States—and easily the most forward-thinking thing Michael Nutter has done since becoming mayor—has all sorts of other benefits, including improving the look of streets and neighborhoods. “It’s a remarkable program that we’re seeing cities all over the country mimic,” says Neukrug. “We’ve even been noticed in England, since they’re rethinking the Thames Tunnel.”

While Green City, Clean Waters might help mitigate the damage from future storms, dealing with the other water issue—rising sea levels—isn’t so easy. The Shore predictions are sobering: As ocean levels rise, all sorts of bad things can happen, from beach erosion to marshland loss. That won’t necessarily make the 127 miles of New Jersey coastline uninhabitable (or, to coin a phrase, unvacationable), but it will certainly make life in Stone Harbor and Margate more volatile. The most angina­-inducing prediction­ from the Union of Concerned Scientists has to do with flooding from increasingly severe storms. “What is now considered a once-in-a-century coastal­ flood in Atlantic City,” its report says, “is projected to occur, on average, as frequently as once every four years by mid-century and once every year or two by late-century.” You might want to ask for a room on one of the upper floors at the Borgata.

If you’re more of a mountain person, I’m afraid you’re still not off the hook when it comes to sea-level rise. Remember the Irene scenario, where a surge in the ocean led to a surge in the bay and ultimately the river? As the ocean level rises, that surge will essentially happen all the time, eventually moving the salinity line—the spot where there’s a transition from saltwater to fresh water—from where it currently exists in the Delaware Bay to somewhere further upstream in the Delaware River. Since you can’t drink saltwater, and since about 60 percent of Philly’s drinking water comes from the river, that’s going to be an issue for each and every one of us.

Tom McGrath Tom McGrath, Chief Content and Strategy Officer of MetroCorp