'Extreme' cloud bank for 16 days and counting in Central Valley; record-cold December possible

Throughout a lot of Central California, a cluster of cussed clouds has lingered for greater than two weeks, bringing durations of intense fog and unseasonably low temperatures — and officers say the stagnant climate sample is more likely to persist.

The low stratus clouds — which seem to stretch from Bakersfield by way of Chico and west into the Bay Space — proceed to create visibility considerations on roadways and will assist foster a record-cool December, mentioned Carlos Molina, a meteorologist with the Nationwide Climate Service in Hanford. Temperatures have remained effectively beneath common the previous few weeks, he mentioned, with highs solely within the higher 40s for a lot of the area, about 10 levels beneath common for this time of yr.

“If we proceed to carry on to this sample for a majority of this month,” Molina mentioned, “it might positively put us within the document books for the way cool we’ve been this December.”

Already, the low, heavy clouds and fog have caught round an abnormally very long time — 16 days as of Tuesday, by Molina’s rely. Forecasts present it may proceed by way of the week.

“Occasionally, once we do get this climate regime throughout Central California, sometimes it lasts a couple of week,” Molina mentioned. So this yr’s sample is “on the acute aspect.”

Earlier than and through this 16-day stretch, some areas on this area have seen thick, dangerously opaque tule fog kind briefly, slashing visibility to nearly zero. Climate service officers confirmed that the world’s signature fog developed on Nov. 20, 25 and 26, forming in spots that noticed temporary breaks from the clouds throughout the day, permitting the dense late-night and early-morning fog to develop. On Thanksgiving Day, elements of Kern County additionally skilled tule fog.

In these cases, the tule fog lifted comparatively rapidly, whereas the blanket of low clouds remained, creating ongoing visibility points.

Dense fog has been an virtually each day concern since late November, notably on roadways that transition from greater elevations into the decrease valleys, reminiscent of within the decrease Sierra foothills, coastal ranges and alongside the Grapevine, Molina mentioned. In these spots, drivers briefly enter the low clouds, the place visibility turns into extraordinarily restricted, he mentioned.

A dense-fog advisory stays in place throughout the Central California foothills by way of at the least Tuesday morning.

However, Molina mentioned, “we’re anticipating to see this all of this week.”

A excessive strain system lingering off California helps to push any doable storms north towards the Pacific Northwest and Canada, leaving little to intervene with the tenacious clouds over Central California.

“There’s nothing to interrupt up the low stratus,” Molina mentioned.

Consequently, for now, there’s little likelihood that the dramatic tule fog will develop once more.

That climate phenomenon requires some clearing of skies and a few warming of the bottom. Technically often known as radiation fog, it could develop in any valley, however the geography of the Sacramento and San Joaquin valleys could make it notably intense, leading to a number of huge freeway pileups lately.