The Washington area basked in record-breaking, coat-shedding 74-degree weather yesterday as snow flurries drifted over the Los Angeles area for the first time in 30 years and much of the rest of the country was beset by crippling floods, snowstorms, strong winds or freezing rain.

Temperatures will begin to drop in the Washington area today, however, as the storm system plaguing the Western states moves toward the area, bringing with it occasionally heavy showers and thunderstorms and the chance of light snow flurries tonight, forecasters say.

The high today may reach 68 degrees, then is predicted to drop to 25 to 30 late tonight and early Sunday. Sunday's high is expected to be 35 to 40.

The area's unseasonably warm weather during the past several days was caused by a surge of tropical air from a high pressure front over Bermuda that extended along the Gulf Coast states up into parts of New England, a Weather Service spokesman said.

A ridge of air extending from the northwestern to the southwestern parts of the country kept cold air in the west from moving eastward for a time, the forecaster said. However, that ridge has begun to weaken.

Washington's temperature climbed to 74 degrees at 11 a.m. and 2:30 p.m. yesterday, a mark one degree higher than the record set for the date in 1966, a Weather Service spokesman said. That 74-degree reading was only two degrees under the all-time high recorded for the month of December, set in 1973, he said.

One year ago today, the Washington area was shivering in temperatures in the 20s and 30s.

Residents elsewhere in the country know that feeling well. In Los Angeles. where water in some swimming pools froze, temperatures plunged to a record 30 degrees, the city's coldest December temperature ever, United growers in both southern California Press International reported. Fruit and Arizona fought to save their orchards.

Freezing rain hit Missouri, Illinois. Indiana and Oklahoma.Severe snow storms engulfed Chicago, which has had 24 inches in the past two weeks, and part of Arizona.

Strong wind gusts were reported in parts of Louisiana and tornadoes were observed in Alabama and Tennessee. An ice storm that hit southern Illinois brought down power and telephone lines and shut many schools.

Denver had its lowest temperature in 51 years -- 10 below zero. Meanwhile, the coldest spot in the nation was in Yellowstone National Park in Wyoming where the mercury read minus-43 degrees early yesterday.