Sometime around 7 a.m. yesterday, the D.C. emergency command center notified the Metro transit system that it would start snowing. Around noon.

The problem was that the prediction was three hours off and the result was that thousdands of late morning commuters fund themselves caught in the middle of the winter's worst storm.

According to Thomas S. Trimmer, director of transportation for Metro, the worst time for snow to start falling is during rush hour. "I'd say 90 per cent of the people," were at work Trimmer said, "and the problem was the 10 per cent who come in after in after the government rush."

An estimated 150,00 commuters ride the buses to work in and around Washington, according Metro estimates. So something in the neighborhood of 15,000 persons were either caught on buses or in the cold when the snow hit. Many of those on buses had to get off and walk when their drivers became frustrated by the icy streets.

"The worst street in the city has to by Wisconsin Avenue," according to Terry Jackson, a Metrobus driver, who arrived an hour and a half late at the Federal Triangle after taking his T2 bus down WIsconsin.

Drivers on Connectucut Avenue and other city and suburban streets also reported icy conditions.

By noon yesterday, buses still were arriving an hour to an hour and a half late at the Federal Triangle, at 13th and Pennsylvania NW, one of the main turnaround points.

Dale Schult, a Metrobus supervisor, sat in his little shack at the Federal Triangle, looking out a window up 13th Street.

"Everything got behind right there on 13th Street," Schult said, gesturing at the slight incline in the street. "The salt trucks still hadn't salted there yet. The buses couldn't get down, so they couldn't get back up."

Under an arrangement between the city and Metro, the city provides trucks to combat snow and Metro provides the drivers to operate them. Metro cannot put the trucks out on the street until notified to do so by the city. The city, according to Trimmer, called at 9 a.m. to tell Metro to put the trucks out. Trimmer said 20 trucks were out by 9:30, but by that time snow was sticking and piling up, frozen. A sheet of ice formed on the streets.

"They should have been on standby because they've been talking about snow since 6 o'clock this morning," Schult said. "I say it was the fault of the District Highway Department."

"When the snow started falling," Trimmer said, "it froze immediately. I don't want to second-guess the highway department, but I believe the earlier you can get those trucks out, once you know it has started snowing, the better off you are."

At about 12:25 p.m., an L4, which comes down Connecticut Avenue, wheeled into the Federal Triangle - only about 10 minutes late. An L4 that arrived 10 minutes earlier had been 55 minutes late. Schult, noting that "experience accounts for the difference," went out to talk to the driver, Joe Johnson, a 20-year veteran of the bus business in Washington.

"How's Connecticut Avenue?" Schult asked.

"Beautiful," Johnson said. "Beautiful. The only place it's bad is coming down New Hampshire Avenue - just slick as glass."

By yesterday evening's rush hour, the buses appeared to be moving well, with small groups of commuters waiting at bus stops.

The brightest spot of all in the Metro system was the subway, which ran without any snow-related problems, according to Anthony J. Stefanac, general superintendent of rail operations. There was a 20-minute gap in service between 10:45 and 11:05 a.m. caused by a mechanical problem. But that, according to Stefanac, had nothing to do with the snow.