The weather phenomenon called La Nina will likely cause a mild winter this year in southern states but a rainier and snowier winter in the Northwest and Great Lakes, federal officials predicted yesterday.

La Nina is a periodic cooling of a large area of the tropical Pacific Ocean. It can alternate with an ocean warming called El Nino. Both can have impacts on weather worldwide.

The regional winter forecasts from the National Weather Service were:

* Alaska: Colder and drier than normal.

* Hawaii: Colder and wetter than normal.

* Pacific Northwest: Above-normal precipitation and increased storminess. Near-normal temperatures. Above-normal snowfall.

* California: Below-normal temperatures near the coast. Above-normal precipitation in the north, below normal in the south.

* Southwest: Above-normal temperatures, below-normal precipitation. Below-normal snowfall in eastern New Mexico.

* Northern Plains: Near-normal temperatures and above-normal precipitation. Significant arctic outbreaks likely.

* Rocky Mountains: Near- to above-normal temperatures. Above-normal precipitation in the north, below normal in the south.

* Midwest: Near- to above-normal temperatures as you go from north to south, above-normal precipitation entire region. Above-normal snowfall in upper Midwest.

* New England: Warmer than normal in southern New England; jet stream makes prediction uncertain in northern New England.

* Southern Tier: Warmer and drier than normal, with dryness most likely in New Mexico, south and west Texas and Florida. Below-normal snowfall in northern Texas and central Oklahoma.

* Mid-Atlantic: Milder than normal with near normal precipitation east of the Appalachians.

* Ohio and Tennessee River valleys: Warmer and wetter than normal. Increased number of heavy precipitation events and an increased risk of severe winter weather. Above-normal snowfall.

* Great Lakes and Northeast: High degree of uncertainty. Considerable variability from week to week with above-normal temperatures in southern areas and closer to normal in the north. Above-normal snowfall in northern Great Lakes. Near-normal precipitation south and east of the Appalachians, above normal elsewhere.