The month of January started with a couple of moderate storms, but shortly after that the jet stream moved north of California… and hasn’t returned. It’s been more than 3 weeks since rain has fallen in the San Joaquin Valley, and don’t look for that to change anytime soon. Conditions have been perfect for dense Tule Fog to form in the Valley… and don’t look for that to change anytime soon, either.
As we entered the month of January, seasonal rainfall totals around the Valley were near 200%, or twice our usual amount. We’re still above average as we enter February, but it’s closer to 125% – 140% now. Low clouds and fog replaced storm clouds, and that fog has been THICK in the Valley lately. Fog knocked visibilities down to just a few hundred feet Saturday morning, which was at least partly responsible for a 59 car pileup on Highway 99 in southern Tulare County, near Earlimart.
Officially, Fresno-Yosemite International Airport recorded 16 days of dense fog in January, which is 5 days above average for the month, and the most we’ve had in January since 2003. Dense fog is defined as when the Visibility drops to or below 1/4 of a mile. There certainly were other days in January where the visibility at Fresno-Yosemite almost dropped that low (like 1/2 mile), but those aren’t counted… even though that’s still a pretty foggy day…