Vowing to avoid a repetition of last winter's chaotic snow emergency, federal, state and local officials unveiled a new weapon yesterday in the Washington region's perennial battle against the elements: a plan.

After a summer spent studying the lessons of the previous winter, a task force of the Metropolitan Washington Council of Governments has recommended a series of steps to avoid the confusion and paralysis that gripped the area when 21 inches of snow fell on the city and suburbs in a 10-day period last January.

"The main thrust of the plan is on improved procedures, better communications, better coordination, better information sharing and improved notification among local jurisdictions and agencies," said Joseph Yeldell, emergency preparedness director for the District and the chairman of the COG task force.

Presented at a news conference yesterday by D.C. Mayor Marion Barry and Fairfax County Board Chairman John F. Herrity, the snow emergency plan makes the following recommendations:State and local highway departments should concentrate on clearing "snow priority routes" -- key arteries serving the city and suburbs -- to a depth of two inches or less. Plows should forgo secondary and neighborhood streets until the priority routes have been cleared. Authorities should work to establish a "regional communications system" to share critical information among appropriate government agencies. If snow falls during the night, representatives of 18 agencies and jurisdictions will hold a conference call at 5:15 a.m. to announce decisions about school and office closings. If snow forces the release of federal employes during the day, the government will stagger their departure so that those with the greatest distance to drive leave first. In other words, a worker who lives in Loudoun County would leave half an hour before someone from Fairfax, and so on. Authorities should develop a public education program to spread the word about the snow plan before winter sets in, as well as a means of disseminating information through the media and other outlets during an actual snow emergency.

The 70-page snow emergency plan, equipped with a glossary, maps and pages of phone numbers, was hammered out by representatives from a dozen government agencies, including the U.S. Office of Personnel Management, the D.C. Department of Public Works, Metro and the Maryland and Virginia highway departments.

"It makes sense," Barry said in an interview after the news conference. "We have to coordinate with Maryland and Virginia so you don't end up crossing the 14th Street bridge and finding out that I-395 is not clear."

On the first day of last winter's snow emergency, authorities cited poor coordination as the cause of massive tieups on snowbound highways leading out of the city. Virginia highway officials complained that they received just 15 minutes warning before thousands of federal employes were dismissed, which did not give them adequate time to open gates on the reversible lanes of Shirley Highway.

Barry, who was vacationing in California during the first days of the snow emergency and was heavily criticized for his absence, said: "If it's a major snowstorm, I'll be involved. I'm only a phone call away from anyone and I have several hot lines in my house."

The snow emergency plan is still considered a draft document. At the end of next winter, it will be evaluated and, if necessary, adjusted before being formally adopted.

Participation is voluntary but virtually all government agencies that are affected by the weather in the Washington region have agreed to go along with it, officials said. COG plans to begin contacting private employers to ensure their cooperation as well.