Bring in Aunt Matilda's favorite colicrott plant tonight. The first hard freeze of the season is on the way, says the National Weather Service.

Forecasters are calling for temperatures to plunge into the upper 20s tonight and early tomorrow -- the first freezing weather since last March -- and to stay cold through Sunday.

After two months of topsy-turvy weather -- including a freak snow-storm on Oct. 10 and and a nine-day record heat spell that just ended this week -- the Washington area finally appears to be heading toward something resembling typical late autumn conditions hereabouts.

Weather Service forcaster Walter Green said variable cloudiness and brisk winds with a chance of scattered snow flurries today and tonight should give way to partly cloudy conditions tomorrow and fair skies through the rest of the weekend.

But temperatures will drop into the upper 20s and low 30s at night Saturday and Sunday and push up only to about 40 degrees during the day. On Monday, Green said, daytime temperatures will moderate slightly with highs in the mid-40s.

What about the rest of the winter ahead of Us? A weather service 30-day outlook issued yesterday calls for near normal temperatures but above-normal precipitation for the Washington area during that time.

After that, things get a little vague.

At a press conference called by National Weather Sevice offiicials yesterday to give their annual long range prediction for the winter throughout the nation, the experts said, quite frankly, they're not at all sure about Washington -- and most of the rest of the East Coast as well.

Speaking guardedly, weather service prediction branch chief Donald L. Gilman said the thousands of bits of meterological data pumped into government computers to help determine weather patterns for this winter "provided no clear-cut evidence how the winter will be here."

The computers did a little better elsewhere. Gilman distributed copies of a map showing the expected pattern of above-normal or below-normal temperatures throughout the country. It showed a broad band of below-normal temperatures from the Great Lakes and western New York south to the Gulf Coast and New Mexico.

Above-normal temperatures were shown for the Pacific Northwest and upper Rockies, a strip of Arizona and California from Tucson to San Francisco and the eastern half of New England.

But large swatches of the East Coast (including Washington), southern Florida and the Great Plains were marked "I" for "indeterminate."

In these areas, the National Weather Service said, carefully hedging its bets, there is a "50 percent chance of above-normal" and "50 percent chance of below-normal" temperatures for the winter.

As for Washington, Gilman said, the area will probably be wetter than normal -- in the form of either rain or snow -- "but we're right on the fence" as to whether temperatures will be above or below normal.

Last year, Gilman noted, the National Weather Service correctly predicted a colder-than-normal winter for western United States but incorrectly called for a mild winter in the East.

He said the "state of the art" of long range predictions, despite weather satellites and sophisticated computers, is still rudimentary. Asked what confidence he had in the much more specific week-to-week and day-to-day predictions that some private forecasters provide for the winter, gilman answered: "None."