Of the almost 800 state Department of Transportation (DOT) plow trucks fanned out across the state Tuesday, about 210 of them were plowing snow east of the Connecticut River.

With schools, state agencies and some town halls closed, DOT Spokesman Josh Morgan said people stayed off the roads during the height of the storm in the morning.

Morgan said crews had reported to 13 garages in the eastern part of the state ― including ones in Colchester, Groton, Norwich and Waterford ― between 1 and 3 a.m. in preparation for the storm. Then it was time for them to head out to lay down a salt brine before snow began to fall after 4 a.m.

“That salt brine, that pretreatment, really makes a big difference, especially on the Gold Star Bridge,” he said. “They make sure they hit some of the ramps that are prone to freezing up a little more than, say, the rest of (Interstate) 95.”

National Weather Service analysis showed 2-4 inches falling across New London County by 1:30 p.m., with up to 15 inches in other parts of the state as a band of heavy snow bisected the state from the New York border to northeastern Connecticut. The storm has passed by the region by mid afternoon.

Morgan said the snowfall was intense at times, coming down at a rate of an inch-and-a-half to two inches per hour across much of the state. That much snow can be difficult to keep up with, according to the DOT spokesman.

“They go out there, they do a pass, and 20 minutes later it’s snow covered again,” he said.

He anticipated the plow trucks would be out well into the night, and maybe into the morning, given temperatures expected to dip to around 23 degrees.

New London Mayor Michael Passero on Tuesday afternoon said the city’s Public Works crews were doing good work in keeping roads cleared as the snow fell on Tuesday but the real challenge might come overnight as its gets colder.

“They’re working hard to get as much cleared as they can before it all freezes overnight,” Passero said.

The frozen snow is harder to move and can make for hazardous driving and walking conditions. He said crews would be out much of the night clearing and treating the roads.

Police on Tuesday dealt with occasional reports of branches on wires and downed trees because of the weight of the snow. Roads were temporarily closed in the towns of Ledyard, New London and Montville. No road closures were reported as of late Tuesday afternoon.

City of Groton Mayor Keith Hedrick said Tuesday afternoon that the city was interested in whether or not the storm or high tide would result in additional flooding at Eastern Point Beach, but there were no issues with flooding.

He said the city is continuing to urge residents to adhere to the parking ban so the city can plow the streets completely. If people continue to remain off the streets, he said, it will make it safer when crews are plowing.

Eversource reported minimal power outages among its customers in the region with the most being in Stonington where 154 people were without electricity as of 3 p.m.

Shortly after 1 p.m., Bradley International Airport in Windsor Locks reported it was open amid ongoing snow-removal operations. At that point, 11% of Tuesday’s scheduled flights had been canceled and roughly 6% were delayed, Brian Spyros, the Connecticut Airport Authority’s public information officer, announced in a news release.

Additional cancellations and delays were possible the rest of the day and Wednesday, Spyros said. Passengers were advised to confirm the status of their flight before heading to the airport.

Staff writers Greg Smith, Kimberley Drelich and Brian Hallenbeck contributed to this report.

e.regan@theday.com