Federal climatologists predict that dry conditions will generally recede over the winter in Oregon, Idaho, Washington and parts of Northern California, providing an early and upbeat outlook on next year’s water supply. The Climate Prediction Center forecast a 70 percent chance of a weak La Nina, a cooling of the ocean around the equator. La Nina generally tilts the odds in favor of wetter and cooler winters in the northern U.S., according to the center. It’s not a sure bet, though. La Nina’s influence will vary by region. The odds it stays through the winter are 55 percent.