After a siege of winds that began late Wednesday night with gusts up to 55 mph, a downed tree knocked out service on SEPTA’s Paoli-Thorndale Regional Rail line, the most heavily used one in the system, for two hours at the height of the Thursday evening commute.

Service in both directions was suspended around 4 p.m., and after it resumed, riders had to endure 45-minute delays, said SEPTA spokesperson Andrew Busch. About 20,000 riders use the Paoli-Thorndale line daily.

The tree came down on the Amtrak portion of the SEPTA-Amtrak shared track near the Daylesford station in Chester County, Busch said.

Chester County and the rest of the region was lashed with wind gusts from a “bomb” cyclone that doused the area with its heftiest rains in months — up to 3 inches, the National Weather Service said — and then hammered New England with hurricane-force gusts, including a 90-mph reading in Provincetown, Mass.

The storm, which was centered in northern New England on Thursday night, could set a record for the most intense October storm so far north, meteorologists said. It deepened so rapidly that it met the technical criterion for a meteorological “bomb.”

The rains shut off around here Wednesday evening, but then “the winds picked up real quickly,” said Valerie Meola, a meteorologist at the National Weather Service Office in Mount Holly. Gusts reached as high as 59 mph in Ocean County, she said, and 55 mph in West Grove, Chester County.

The howling came out of the west: Winds circulate counterclockwise around centers of storms, thus the west winds to the south of the center.

Sustained strong winds can be especially taxing on trees this time of year, when they are still weighted with leaves, she noted.

Numerous downed trees were reported throughout the region, according to the weather service, and Peco Energy said about 30,000 customers lost power Wednesday night into Thursday.

Meola said the winds were expected to die down after sunset, when the mixing of the air tends to back off.