A tropical storm that drenched the region for several hours Tuesday delivered only a fraction of the rain it could have, according to local National Weather Service observer David K. Mattice.
Tropical Storm Isaias, at one point a Category One hurricane with 85 mph winds, had the potential to create “catastrophic” flood levels across Otsego and Delaware counties, with rainfall totaling as much as 15 to 20 inches, according to Mattice.
By 4:30 p.m. Tuesday, the storm had produced 2.88 inches of rainfall, just shy of Mattice’s 3-inch prediction. He said he expected “rain-free” skies at 7 p.m. and partly cloudy skies through the overnight hours.
“We weathered the storm very well,” Mattice said. “That was a complex storm system.”
The storm made landfall in southern North Carolina around midnight and picked up speed after encountering a low-pressure trough, which carried it up just inland of the coast at 40 mph, according to Mattice.
“That’s the quickest I’ve ever seen one move,” he said.
Had the storm traveled at a regular clip of 5 to 10 mph, Mattice said, the region could have seen at least five times the rainfall.
“It could have been a major flood-maker,” he said.
Isaias brought with it more than 90 reports of tornadic action as it spiraled up the East Coast, mostly concentrated in Virginia, Maryland and Pennsylvania, where homes were leveled and 3 million to 4 million people were left without power, according to Mattice.
Rain-wrapped tornadoes are less intense and shorter-lived than typical tornadoes, Mattice said, but can pose a greater threat because rain obscures their visibility. Radar-indicated tornadoes were reported Tuesday in Liberty and northeast of Albany, but caused no apparent damage.
Delaware County Emergency Services received no reports Tuesday of storm-related incidents, according to director Steve Hood.
County emergency personnel were continuing to monitor the areas around small streams and creeks, which are more prone to flash floods as rocks and debris continue to pile up in the aftermath of a storm, Hood said.
The New York State Electric & Gas Corporation reported more than 91,000 customers without power by 5 p.m. Tuesday. Delaware County was among the hardest-hit areas, counted among the 7,110 outages reported by the company’s division in Liberty.
The most intense rain arrived between noon and 1 p.m. Tuesday, Mattice said, describing the deluge as “a saving grace for all the lawns and farmers,” as the area was on the verge of a mild to moderate drought.
The National Weather Service issued a flash flood watch Tuesday for Broome, Chenango, Delaware, Otsego and Sullivan counties, as well as Lackawanna, Luzerne, Pike, Susquehanna, Wayne and Wyoming counties in Pennsylvania.
NWS reported minor flooding — about 10 feet at 7 p.m. Tuesday and expected to rise to 12 feet by 2 a.m. Wednesday — of the Beaver Kill in Cooks Falls. The West Branch of the Delaware River was reported to be nearing flood stage in Walton and expected to crest at 9.3 feet around 7 a.m. Wednesday.
“This had all the makings of something that could have been catastrophic,” Mattice said, noting that the storm’s inland path saved the region from what could have been damaging winds. “If it had stalled out, it could have been catastrophic.”