LAKE COUNTY >> Dry weather is forecast for Northern California on Thanksgiving, but between now and then, watch out.
A cold winter storm from the Gulf of Alaska is expected to move into the north state Monday night, with the worst of the storm hitting some areas on Tuesday afternoon. Lake County should receive at least a quarter of an inch of precipitation, although some forecasts call for more.
According to the National Weather Service projections, steady rain will arrive around 11 a.m., with heavier precipitation following. Models vary, with some indicating showers will taper off by 5 p.m.
Accuweather begins ramping up the chance of rain at about 5 a.m. Other services call for wet weather at 9 a.m.
The National Weather Service is forecasting heavy snow in the mountains Tuesday with slick roads and traffic delays in the valley.
The advisory from the Weather Service’s Sacramento office suggests motorists “avoid travel” between 11 a.m. and 5 p.m. Tuesday if possible.
A foot to a foot and a half of snow are expected above 6,000 feet. The forecasts says zero-visibility “whiteouts” are possible above 3,000 feet, with snow possible as low as 2,000 feet overnight from Tuesday to Wednesday.
Cold and dry weather is forecast for Thanksgiving Day.
There is no association of this event with El Niño, though conditions remain in place for at least average amounts of rainfall — possibly more — hitting Lake County and northern California between December and March.
Still, Michelle Mead, a forecaster for the National Weather Service in Sacramento, said Northern California’s winter definitely won’t make much of a contribution on water supplies.
“There’s a 66 to 73 percent chance of average precipitation for Northern California.”
It would take more than a rainy season of 200 percent of normal to help the situation, although with that amount, flooding and devastation would be likely.
“We can’t say how much rain we’ll be getting,” said Mead about forecasting this winter, “but we can say whether it will be above average, average or below average,” she said.
There’s no drought-removing deluge in the forecast.
Even average rainfall can spell trouble . A concentrated downpour will likely mean flooding in many areas. Erosion in the fire area remains a concern.
Referring to PG&E meterologists’ outlook, Paul Moreno of PG&E said “We anticipate a slightly above normal wet winter for the north valley region, with the wettest periods projected to occur in January to March time frame.”
Whether the rain comes, Mead stresses everyone should be prepared for the worst, from stockpiles of food and water, to batteries and evacuation plans.
El Niño, Mead explains, is a warm-water stream in the ocean that is in contact with the air and impacts the jet stream. The path of the jet stream dictates the kind of weather — cold and snowy, warm and wet or something in between, or not any of the above. There have been El Niño-impacted winters that have been dry.
El Niño “changes the storm track,” she notes.
Scientists believe this system may be one of the three most powerful El Niños on record. During the 1998 event, Clear Lake topped its flood stage by more than two feet on the Rumsey Gauge, peaking at 11.4 Rumsey in February.
The lake is currently at 0.49 Rumsey, far below the normal of just over 7 feet.
Laura Urseny, Chico Enterprise-Record, contributed to this report
