A quintessential Pineapple Express plume of moisture coming from Hawaii, aimed at the Bay Area, is likely to bring significant rainfall early next week. And anyone who was planning to travel Sunday or Monday for the Christmas holiday may want to consider contingency plans.

There is no total certainty around what will come our way next week. But what seems all but certain is that today's light rains will be followed by more light rains as the week goes on, and by Sunday, those rains could turn heavier in the Bay Area, with even stormier conditions lasting several days.

The third in a series of storm systems coming toward the Bay Area will be coming in by Sunday evening, December 20, and could bring periods of heavy rain and wind.

"That system is supposed to move in by Sunday," says National Weather Service meteorologist Roger Gass, speaking to Bay Area News Group. "That one will continue on and off during the week. So Christmas travel and any plans will be 100 percent affected by it."

The National Oceanic and Atmospheric Administration's Climate Prediction Center forecasts further ahead, saying that there is an above 60% chance of heavy precipitation all along the coast on Christmas Eve and Christmas Day. An advisory from that agency is titled, "Atmospheric Rivers Bringing Major Holiday Travel Hazards Across the West."

High winds next week, the agency said, could also present hazards both for power lines and for air travel.

As the Chronicle reports, the atmospheric river setting up for the weekend will provide the fuel for significant rainfall, but the "trigger" which would be "in the form of a secondary surface low pressure system developing along the boundary between the cold front and the atmospheric river" still has to materialize.

As for snow in Tahoe, warm temperatures mean that rain is likeliest in much of the region, with snow only above 8,500 feet next week. But somewhere up there is likely to see a white Christmas.

Top image via NOAA