The good news is that it may not rain on the Redskins' victory parade this morning. The bad news: It may sleet instead.

Whatever the weather -- and it is all but certain to be awful -- Washington is gearing up for a massive, effusive Super Bowl celebration featuring a parade, rally and White House reception for the returning gridiron gladiators.

Grateful fans are tripping over each other to show their admiration for the football team.

Civic pride propelled the D.C. Council to declare not one but two Doug Williams Days honoring the Redskins quarterback: tomorrow and Feb. 11. "As they say in the country, every hog has his day," said council member Frank Smith Jr. (D-Ward 1). "Doug Williams is a good hog and deserves two days."

Williams and his teammates also were praised in a resolution passed unanimously yesterday by the Senate.

Williams, the game's most valuable player and the first black quarterback to start in a Super Bowl, was lauded in the resolution for "ignoring injury and throwing brilliant passes . . . . {Williams} led the Redskins to a record four touchdowns in the second quarter that sealed the Super Bowl victory and shattered one of the worst racial barriers in sports."

Tomorrow, radio station WOL will present Williams and other players with a 21-block-long scroll signed by about 50,000 fans.

Some radio and television stations plan live coverage of today's 11 a.m. parade up Pennsylvania Avenue NW and the 12:15 p.m. rally at the District Building. The lovefest continues at a 2 p.m. White House reception at which President Reagan will congratulate the players, who will give the president a jersey and a football.

District government workers will be excused from their duties from 10 a.m. to 2 p.m. to attend the festivities. And at Reagan's request, the Office of Personnel Management has encouraged federal agencies to allow workers two hours of paid leave on top of their regular lunch breaks; each agency will make its own leave policy, said an OPM spokesman.

However many fans show up for the parade, they should be certain to carry umbrellas, said National Weather Service forecaster Scott Prosise. Temperatures were expected to drop sharply overnight and should be in the 30s by the start of the parade.

The last Redskins Super Bowl victory parade, in 1983, drew 500,000 people to similarly cold and rainy streets. That is about the same size as the celebration that greeted the American hostages returning from Iran in 1981. The 1984 parade for the team that lost the championship game was held in messy slush and attracted 100,000 fans.

Joseph Yeldell, director of the D.C. Office of Emergency Preparedness, said the parade will go on regardless of the weather. The Redskins, protected by hundreds of D.C. police officers, will ride the 10 blocks from Third Street to the District Building in tourmobiles, with a few prominent players highlighted in separate cars.

Bands from several area high schools will march in the parade.

Major public school systems planned to hold classes as usual. But, noted D.C. school spokeswoman Cheryl Johnson, "If parents decide they want their children to see this historic event, they can do so, provided we get a written excuse the next day."

Mayor Marion Barry will introduce the Redskins at the rally, which will feature proclamations and speeches from Virginia and Maryland officials. Coach Joe Gibbs will speak for the team. Yeldell said the speeches will be few and short.

Williams and other Redskins will be at the Howard University gymnasium at noon tomorrow to accept a scroll packed with drawings, poems and other messages from schoolchildren and other fans. An estimated 50,000 people signed the congratulatory scroll, a project initiated by radio station WOL.

"It started after Doug was sat down on the bench earlier in the season and he went on TV and cried in an interview," station owner Cathy Hughes said. "We started the scroll to show our support, and the response was incredible. We started this before he was Mr. Popularity."

Mr. Popularity, touched by the scroll and other fan support, spent yesterday at his Reston apartment reading fan letters and attempting to rest. It was a futile effort.

Even his mailman knocked on the door to congratulate Williams. "I never saw better football played," the letter carrier said.

"It surprised all of us," said Williams.