Share with Friends

After our wet December, will the storms and rainfall return to California later in January? The models hint they will, but we may have to wait 2-3 weeks to see if they’re correct.

A passing ridge of high pressure gave us nice weather Wednesday and Thursday ahead of another trough digging south, bringing us a weak storm inbound for Friday. (Image 3) This is likely the last rain for a while and it has been trending drier over the past few days.


The rain will cutoff around the Bay Area, so the forecast is tricky. Less than a half inch for Sonoma County and most of the North Bay. (Image 4)


The is strong agreement on high pressure building over the Pac NW after this weekend to around mid-month. (Image 5) That should keep us dry.

Toward the end of the month there are hints that low pressure may return to reopen the storm door. (Image 6) Lots depends on where high pressure over the Pacific sets up. Far enough west and the storm door may reopen. But, right now it looks pretty dry at least until the last week of January.


For those interested, the seasonal patterns may hold some clues. Especially in a La Nina year, seasonal patterns can exert a powerful influence on wet and dry patterns along the West Coast.

The Madden Julian Oscillation (MJO) is stuck in phase 7. This is a measure of location and strength of convection in the tropics. (Imagine looking down on the globe from the North Pole) If it breaks out into phases 8 and 1, our pattern may shift back to wet. (Image 7)

Meantime, the Pacific North American Pattern (PNA), after swinging positive in mid-January, shows signs of going negative again later in the month. (Image  This tends to correspond with low pressure and storms along the West Coast. We’ll be watching.

For its part, the Euro weeklies see wetness return around the last week of January, or early February. (Image 9) And, the CFS long range outlook hints February may be a bit wetter than average. (Image 10) These are very long range outlooks, not forecasts, so take all this with a grain of salt!

We’ll have updates on the January rainfall outlook as the forecast evolves in the coming days.

Support Hyper-Local Community-Based Video News!

Our approach is different.  No ads, and no paywalls. We are committed to keeping News of the North Bay’s content free and open to everyone.  Your generous support of NNB helps to insure that we can continue to provide original, insightful and independent video news reporting for Sonoma County and the North Bay.

Choose a Support Level!

Comments are closed.