La Niña is going to have a mega effect on the 2011-2012 winter season, but so will a wild card phenomenon, scientists say.

Meteorologists at the National Oceanic and Atmospheric Administration (NOAA) released a Winter Outlook report on Thursday.

The evolving La Niña will shape this winter, NOAA Climate Prediction Center deputy director Mike Halpert said in a statement. There is a wild card, though. The erratic Arctic Oscillation can generate strong shifts in the climate patterns that could overwhelm or amplify La Niña's typical impacts.

Major points of the report include the Pacific Northwest and northern California having colder and wetter than average conditions. The same goes for the Northern Plains region.

Wildfire conditions will be above normal in Florida and the south Atlantic coast, and drier conditions are expected in both parts.

The report also spells out bad news for drought-stricken areas in and around Texas: the dry weather will continue.

Hawaii's drought is also expected to continue.