Forecasters say heavy rains, flooding possible
Predictions from local weather forecasters and emergency officials about how the remnants of Hurricane Ivan will affect southwestern Pennsylvania range from just heavy rains to flooding on the scale of the Election Day flood of 1985. Regardless, emergency management officials in Fayette, Greene and Washington counties are making preparations as Ivan, which devastated the Gulf Coast with 130 mph winds Thursday, moves toward the Northeast.
The National Weather Service has issued a flood watch and a river flood watch for most of the state.
Counties in southwestern and south-central Pennsylvania are in the center of the storm’s predicted path, according to David Sanko, director of the Pennsylvania Emergency Management Agency (PEMA).
Sanko said some areas could see as much as 6 to 8 inches of rain, accompanied by serious flooding, and the Pennsylvania Emergency Operations Center has been partially activated to help coordinate emergency efforts statewide this weekend.
“This storm, to date, has been very unpredictable. Pennsylvania could be in for a secondary burst,” Sanko said. “Sometimes because we are in Pennsylvania and not a coastal state, we think hurricanes don’t affect us, but have had our share of devastating flooding.”
Hurricane Juan kicked off the Election Day flood of 1985 on the Monongahela River. According to the U.S. Army Corps of Engineers, 5 to 10 inches of rain fell on the region in the first six days of November 1985. The rains triggered flooding that left five southwestern Pennsylvania counties declared as federal disaster areas.
“I don’t want to scare people, but this is not just another practice. There is going to be some serious flooding,” Sanko said.
Jeff Yates, Washington County Public Safety director, said he already has contacted each municipality and local emergency management official in the county, as well as fire departments, ambulance services and the Red Cross.
“We have to be on our toes here, because we could potentially match the greatest flooding on the Mon that we have on record,” Yates said.
The National Weather Service is predicting that the river at Lock 4 in Charleroi will crest at 42.5 feet at 2 a.m. Sunday, just a few inches below the record flooding in 1985, when it crested at 42.7 feet, a record high.
“This forecast is based on Pittsburgh and Wheeling south getting at least three inches of rain and as much as five inches of rain,” said Lou Giordano, a hydrologist with the National Weather Service in Pittsburgh. “Any local areas that get 3 inches of rain (Friday) will have surface flooding. It looks like the heaviest rain will shift a little bit eastward, so that’s one ray of hope that we have.”
The Mon is expected to crest at 33.4 feet at 6 a.m. Sunday at Point Marion, more than 10 inches below the 1985 flood; 25.6 feet Saturday evening at Grays Landing, well over the 21-foot flood level; and 40 feet at Maxwell Lock and Dam in Brownsville on Saturday evening, with anything over 32 feet considered flood level there. The river crested at 44.4 feet at Maxwell in 1985.
According to the weather service, low-lying areas of West Brownsville flood when the river hits 32 feet at Maxwell, and homes on Middle, Liberty, Jackson, Broadway and Penn streets in West Brownsville flood at 35 feet. The river should be over the 35-foot level at Maxwell by 2 p.m. Saturday, the weather service forecasts.
On the Youghiogheny River, Connellsville can expect severe flooding this weekend, according to Giordano, with the river expected to crest at 18.5 to 19 feet by Saturday evening, well above the 12-foot flood stage. The river is expected to reach flood stage at 8 a.m. Saturday, according to the weather service, and drop back below flood stage Sunday evening.
About 30 homes along the left bank of the Youghiogheny at Connellsville receive water in their basements when the river hits 14 feet, while another 100 homes on Fifth, Sixth and Seventh streets on the city’s West Side are flooded at the 16-foot level, according to the weather service.
Fayette County Emergency Management Agency Director Roy Shipley Jr. said people living in low-lying, flood-prone areas already know to move valuables out of the way of floodwaters, if necessary.
He said the EMA staff notifies fire departments and emergency medical services when the weather service issues flood and storm warnings.
“We’re watching the river and forecast now,” he said Thursday.
The best thing residents can do is to watch or listen to weather forecasts so they can prepare for severe weather, he said.
Greene County Emergency Services Director Jeff Marshall said his dispatchers contact hospitals, nursing homes, water and sewer plants and marinas when weather watches or warnings are issued.
“We try to give those special needs areas some warning,” Marshall said.
Despite the dire predictions from some forecasters, the amount of rain the area receives will depend on Ivan’s path, according to a weather service meteorologist.
“That’s the big question: Where is it going to go Saturday?” meteorologist Rich Redmond said.
Rain was expected to begin falling “in earnest” after midnight Thursday and continue falling – heavy at times – through tonight, leaving behind 2 to 4 inches, Redmond said. Saturday could bring as much as 2 to 5 more inches or as little at 1 inch, depending on the track the storm takes.
A computer model shows that the storm could stall over the Virginia-North Carolina border late Friday or early Saturday. If it drifts to the west and stalls over western portions of Virginia and North Carolina, “it would allow it to continually pump up moisture to Pennsylvania,” Redmond said. This worst-case scenario could result in 2 to 5 inches of rain and even more in the mountains, he said.
As of Thursday afternoon, the forecast called for the best-case scenario, in which the storm would hug the coast, Redmond said. But, no matter which track the storm takes, the area is in for a wet weekend, he said.
“At this point, it does look like we’re going to get a good deal of rain,” he said.
That is not good news, especially since the ground remains saturated and streams and rivers are still a little high from the stormy remains of Hurricane Frances, which hit last week, and the above-normal precipitation that has fallen this year, he said.
“Water levels in rivers and streams are still high from last week, and the ground is very saturated. It just has not had the time to dry out since we had Frances last week,” Richmond said.
Meanwhile, the U.S. Geological Survey has advised state and federal agencies that the hurricane increases the risk for landslides in mountainous regions.
“Given the wet soil conditions we already have in many of these areas, the risk of numerous fast-moving landslides is significant,” said USGS landslide specialist Gerry Weiczorek.
The slope of the land, type of geology, ground saturation and rainfall intensity and duration all play major roles in triggering landslides, he said.
The USGS recommends that people in mountainous areas become familiar with areas where slides have occurred and watch runoff near homes.
It suggests watching or listening to weather forecasts, and listening for any unusual sounds like trees cracking or boulders knocking together. A trickle of flowing or falling mud or debris may precede larger flows.