A lack of storms dipping to the south that started the year over California continues in the Bay Area.
San Francisco International Airport recorded only 0.20 of an inch of rain during January 2013, and as of Feb. 5, no rainfall has been added to this amount.
The prior driest January on record was in 1991, when 0.24 of an inch of rain fell.
A northward bulge in the jet stream, known as a ridge, delivered the dry weather much of the past five weeks.
According to Western Weather Expert Ken Clark, "The jet stream is dipping more to the south later this week and could allow a storm system to bring a bit of rain Thursday into Friday. However, it does not look like the type of system that will bring widespread heavy precipitation."
The storm should not bring a great deal of snow to the mountains, but it will be a chilly system with rather low snow levels.
"The northern Sierra Nevada could have the most significant snowfall since early January with the end of the week storm system, on the order of several inches," Clark said.
Spotty showers and mountain snow showers could reach Southern California by Friday.
A couple of storms sneaked into the Southland, bringing precipitation in the neighborhood of 50 percent of normal.
"In the wake of the late-week storm system, another week of dry weather seems likely," Clark added.
While such a setup with the jet stream often brings warm weather as well as a lack of storms, temperatures have averaged slightly below normal in northern California and several degrees below normal in the Northwest.
Image and thumbnail of the Golden Gate Bridge in the winter by Photos.com.
"This was due to a large pool of arctic air that moved southward over the interior West and filtered toward the coast during the first half of January," Clark stated.
The air brought a frost and freeze as far south as Southern California and the deserts of Arizona.
The magnitude of the cold skewed the averages from central California northward.
Dry weather will continue over California and the Southwest through Wednesday.