The snowstorm that pummeled Washington over the weekend had just gotten started when a man armed with a handgun robbed a Bethesda bank, Montgomery County police said.

It was about 2 p.m. Friday, a little more than an hour before the steadily falling snow began to stick to the ground, when the robber entered the M&T Bank at 7700 Wisconsin Ave., pulled out a handgun and demanded money from tellers. Bank employees handed over an undisclosed amount of cash, and the robber ran through the shopping plaza that sits a block from the Bethesda Metro station, getting away through the rapidly developing blizzard, police said. No one was injured.