The trouble with the last two severe winters, the man from the National Weather Service was saying, is that they don't tell us anything about what the next one will be like.

That's bad news for easterners anxious for an end to repeated blizzards, midwesterners and southerners suffering chillingly below-normal cold or southern Californians inundated by a 3-times-normal rainfall.

The best the weather service can do-even with three of the largest, fastest commercially available computers solving thousands of mathematical equations so complex they don't even have specific answers - is explain a tiny bit about why things have been so bad.

This winter the westerly winds that would normally blow Pacific rainstorms into Washington State and Oregon and northern California are split into two windstreams, a northern one and a southern one.

The northern stream is making an abnormally large loop toward the Arctic, sweeping up around a "blocking ridge" of high pressure across Alaska depositing most of the rainfall there.

That's giving Alaska a much warmer and wetter winter than normal, weather service officials said. But by the time the winds finish their abnormally large loop and blow down across frigid Canada and back into the United States across the northern plains, they are bitter cold and they're responsible for plunging most of the eastern half of the country into a deep freeze.

The southern half of that westerly windstream is abnormally strong this year. It's blowing straight and hard from the tropical Pacific into southern California and northern Mexico much farther south than normal. And it's bringing storm after torrential rainstorm to the normally dry south-western states.

All winter those two streams have been converging over various parts of the United States east of the Rockies, and where the warm, wet Southern air met cold northern air there has been snow - abnormally heavy snow all across the northern and central plains, Texas, the lower Mississippi Valley, and at times even into the East.

Last year things were a bit different.

That "blocking ridge" of high pressure extended farther south. It sat just off the West Coast of the United States and Canada, and all the westerlies swept up in an abnormally large loop across Alaska. There was no southern stream into southern California.

The rains that those westerlies normally bring to the Pacific Northwest and northern California also, for the most part, fell in the vicinity of Alaska last year, officials said. That state has had two unusually mild winters in a row, plus drought.

And last year the westerlies nearly paralyzed the eastern two-thirds of the nation with bitter cold and snow that made the city of Buffalo famous as the winds swept down from Alaska into the United States.

James F. O'Connor, chief of the National Weather Service's forecasts division, said this year's unusual southern stream of Westerlies has helped keep this winter generally warmer than last over the eastern half of the nation, even though it's still considerably colder than normal.

Oddly enough, the Northeast's heaviest snowfall, the great Feb. 7 blizzard that brough record snows to New York and nearly paralyzed Boston for a week, was not a product of these unusual wind patterns.

It was a classic northeaster, spawned off the coast of North Carolina and intensifying as it moved northeast.

Warmer or colder, this winter will still go down as one of the worst in recorded history, and yesterday's weather appeared to be trying to drive that point home.

Snow fell from the Great Lakes through the Ohio Valley into the Middle Atlantic Coast states. Freezing rain glazed the Appalachian and Piedmont areas south of the snow belt. Winter storm warnings were hoisted from Georgia northeast to New England.

A state of emergency was declared in Arizona after three days of heavy rain and floods. But forecasters warned of another "very big storm" on the way.

National Guard troops helped evacuate flood victims in Phoenix, where two people drowned. Hundreds fled from floodwaters in the southern part of the state, and 8,000 Navajo Indians were stranded in knee-deep mud and snow on their reservation.

Rains continued to pelt southern California, drowning a woman in a rubber raft. Sixteen inches of snow fell in Rocky Mountain ski resort areas. The plains states received a foot or more. Ice and winds up to 40 m.p.h. disrupted air traffic to Kansas City and St. Louis and brought a rash of traffic accidents to southwestern Missouri. Chicago's snowfall all-time record climbed to 80 inches. Tornado warnings flew in much of Florida.

Don Gilman, chief of the weather service's long-range prediction group, said that both this winter and last the westrly wind patterns over Asia and Europe were much closer to normal than over North America.

"We've had some tendencies for winters to group themselves in the last several decades. There were five mild ones before the last two . . . and they were cold or nearly normal for the previous 13. But that kind of clustering doesn't exist in the earlier 20th century. So this way just be luck."

"You want to know why we're having this weather" asked O'Connor."Let me give you God's phone number."