Warring weather systems battle it out and region gets soaked in the process
By Adam Smeltz
Published: Thursday, July 11, 2013, 12:01 a.m.
It was a washout waiting to happen.
Oppressive tropical air steaming Western Pennsylvania since June finally erupted, colliding on Wednesday with a cooler high-pressure system from Canada to dump near-record rain on parts of the South Hills and other Pittsburgh suburbs, forecasters said.
“The two pressure systems are going to fight it out but the Canadian one is going to win” by Thursday, said Henry Margusity, a senior meteorologist with AccuWeather.com in State College. He said Western Pennsylvanians this weekend “can actually go out and cut your grass without sloshing in the mud.”
They'll need to dry out first. Torrential rain arrived in two waves — at about 6 a.m., and then about 12 hours later.
Morning storms alone positioned the rain among the region's most intense in a decade, said state climatologist Paul Knight.
The National Weather Service reported about 2.5 inches between 6 and 9 a.m. in some South Hills neighborhoods, a burst that overwhelmed storm sewers, waterways and rush-hour traffic. Pittsburgh's single-day rainfall record for this month is 3.48 inches, on July 28, 1999, though the all-time record for the city is 5.95 inches on Sept. 17, 2004, during Hurricane Ivan, according to the weather service.
One-day rain tallies during July in Pittsburgh have topped 2.8 inches four times since 1927, weather service records show.
Water levels rose dramatically on Wednesday in part because of saturated ground, soaked by frequent storms over the past several weeks, forecasters said. Rain fell on Pittsburgh all but one or two days since June 25, according to AccuWeather.com.
“All the streams and tributaries were immediately bank-full and immediately came out of their banks,” said John Darnley, a weather service meteorologist in Moon. “There was nowhere for it to go.”
One of the worst-hit was Chartiers Creek in Carnegie, where water by midday reached 11.8 feet — up from its normal flow of 1.47 feet, Darnley said. He said nearby tributaries ran as high as 10 times normal levels.
The conditions marked a stark change from last summer, when Pittsburgh recorded just 1.96 inches of rain from June 6 to July 10, according to the New York consulting firm Weather 2000. More than 8 inches fell during the same period this summer, said company chief meteorologist Michael Schlacter, calling the discrepancy “a tale of two summers.”
Overall rainfall in Pittsburgh since June 1 is about 50 percent above average, according to AccuWeather.com. Knight left open the possibility of additional serious storms in the next month or so, “only because there's no substantive change in the way weather patterns are working right now.”
Forecasts through early next week promise sunny skies.
“It would take a while for the atmosphere to reload, to get the sort of goop you've had,” Knight said.
Staff writers Tom Fontaine and Tory N. Parrish contributed to this report. Adam Smeltz is a Trib Total Media staff writer. He can be reached at 412-380-5676 or email@example.com.
Show commenting policy
TribLive commenting policy
You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.
We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.
While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.
We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers.
We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.
We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.
We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.
We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.
- Donor name to be stripped from Penn Hills library
- Trib’s Hiel honored for reporting on Coptic Christians
- Western Psychiatric clinic rampage victim’s parents seek answers, lawyer says
- Newsmaker: Jack Goodrich
- Web of surveillance videos helps ensnare suspect in East Liberty slayings
- Suspect in East Liberty slayings may be part of murder-for-hire case
- Qualifications of Peduto nominee for building inspection chief come up short
- Pittsburgh to foot bill for police working Market Square during St. Patrick’s Day
- Consumers pay high-tech price in privacy for perks
- Students dive into history for contest
- State official: Peoples-Equitable merger saves money for consumers