Forecasters warn late-day storms could be dangerous
Meteorologists and emergency responders in Western Pennsylvania watched closely Tuesday as a storm that could bring high winds and heavy rain to the region brewed in the Midwest.
“Right now, we're just monitoring the weather through the National Weather Service,” said Cory Angell, a spokesman for the Pennsylvania Emergency Management Agency. “The closer you get to the time the storm hits, the more of an idea the weather service guys give you of what you're looking at.”
Initial forecasts from the weather service predicted showers and thunderstorms after 4 p.m. Wednesday with winds between 5 and 7 mph for the Pittsburgh area. By Wednesday night, 1 to 2 inches of rain could fall. Lee Hendricks, a meteorologist with the National Weather Service in Moon, said there is a slight chance of severe weather.
Hendricks expected meteorologists to know more by Wednesday morning about the storm's potential for high winds, heavy rains and flash flooding.
“At this point, we're keeping a close eye on it,” Hendricks said. “It's a little preliminary to be putting out severe weather statements.”
County emergency responders awaited more information from the weather service before taking action. Allegheny County passed information on the storm to the heads of its emergency response teams, said Alvin Henderson, chief of the county's Department of Emergency Services. If a severe storm hits, the county will take an “all hazards” approach, mobilizing swift-water rescue, hazardous materials and medical teams.
“Sometimes, these storms break up and lose energy prior to coming into Pennsylvania or our region,” Henderson said.
Forecast models from the Weather Service show the worst weather could pass south of Pittsburgh. The models predict up to 3 inches of rain in some areas and a slight chance of damaging winds and hail.
Stephen Cropper, chief meteorologist at WPXI-TV, the Trib's news partner, predicted a shot of showers out in front of the storm to hit the region Wednesday morning and more severe weather to develop later in the day.
“We're in a pretty good recipe for severe storms,” he said.
The storm has the potential to develop into a derecho, some meteorologists said, but Hendricks said the probability is low. Not all the ingredients for a derecho are present, including high temperatures, Hendricks said. Wednesday's temperatures are expected to be in the low 80s.
Derecho wind storms occur once every year or two across the central and northeastern U.S. in a band from Texas to New England. They can pack winds of 75 mph or more and maintain their intensity for hours as they sweep across vast distances.
Such a storm system last passed near Western Pennsylvania June 29-30, 2012, Hendricks said. The storm killed 13 people nationwide and pummeled Maryland, West Virginia, Ohio, the District of Columbia and Virginia, where emergencies were declared.
“We tend to be careful using the D word, but yes, a derecho is possible,” Bill Bunting, a meteorologist in the weather service's storm prediction center in Norman, Okla., said of the current storm. “It's scary because of the potential, but we don't want to over-forecast.”
The Associated Press contributed to this report. Aaron Aupperlee is a staff writer for Trib Total Media. He can be reached at 412-320-7986 or firstname.lastname@example.org.