Mostly dry weather weather through most of the week with chilly nights and high temperatures near to above normal. Slight chance for light precipitation Friday into Saturday and again early next week, mainly across the mountains and foothills.
Observations at Modesto at 3 am were showing some mist with a visibility of 2.5 miles, 4 miles at Stockton. Some patchy morning fog could develop through around 10 am this morning for portions of the southern Sacramento and northern San Joaquin Valleys. Dense fog is not expected to become widespread this morning, though.
Upper level ridging will be flattened a bit today as a weak shortwave passes through the Pacific Northwest. This will just bring just some increased cloud cover through the day and slightly cooler temperatures. Current satellite shows some high clouds just beginning to spread onshore.
By Wednesday, the high pressure ridge will rebuild. Clear skies and light winds should bring a better potential for morning fog, with probabilities for fog in the Valley from Chico southward around 50% to 75% through 10 am.
Morning frost is also possible. Light north winds develop in the afternoon and continue into early Thursday. These along with some high clouds should reduce the potential for fog for Thursday morning.
Wednesday and Thursday high temperatures will be above normal, generally in the mid 60s for the Valley.
A shortwave with a cold front moves in Friday afternoon and evening then pushes through overnight. This system pushes into Southern California later Saturday. The NBM continues to show limited moisture with this system, with even the northern Sierra having just 10% change of getting more than half an inch of precipitation.
Snow levels are projected to be around 5,000 to 6,000 feet, with an inch or less of snowfall currently forecast, so impacts to mountain travel should be limited.
Extended Discussion (Saturday through Tuesday)
Lingering showers possible, mainly over the Sierra Nevada, Saturday as upper low moves through and closes off over SoCal. Drier weather Sunday into Monday as upper ridge builds inland. Another short wave trough drops into the area Tuesday with some additional light precipitation possible.