Thunderstorms, High 70s, then Atmospheric River?

We know, it’s been a crazy winter.  And although it’s not something that most of us want to hear, forecast models are coming into agreement that in a week’s time we could be talking about an atmospheric river storm arriving in the North Bay.  Yes, another one!

First though, Sonoma and Napa counties were treated to a morning of thunderstorms, lightning, steady rain and hail Thursday, as a strong squall line formed, generated by a low pressure center passing inland to the north of our region.  Here’s what it looked like on radar.  The rain will let up by late on Thursday, with sunny skies returning Friday.

Now, back to the possible atmospheric river.  The graphic below shows the most likely scenerio for next Friday and Saturday, April 5th and 6th.  It’s worth mentioning this far out because models are in decent agreement that a plume of moisture will be pointed directly at the Bay Area.

Of course, the exact location and strength of the AR event are impossible to know yet, but there is fairly good agreement that a wet period will take place beginning around Thursday or Friday of next week.

For the present however, the sun will reappear across Sonoma County by Friday, as the storm that gave us a few days of rain and Thursday’s thunderstorms can be seen spinning off into Oregon and extreme northern California.

Once it moves out, the weekend ahead looks great with lots of sun, and temperatures warming into the 70s.

Santa Rosa, Windsor, Sonoma, Healdsburg, Sebastopol and Rohnert Park may reach the high 70s by Sunday.  The NWS is predicting 78 in Santa Rosa!

After the beautiful weekend, more showers may arrive by late on Monday into Tuesday. But this first storm should be light, with the heaviest rain staying up in far northern California.

After a break on Wednesday, the period from Thursday through Saturday may be wet.  Whether or not an atmospheric river arrives, the models are in good agreement that the period will be stormy.  Here’s how the GFS model forecasts the Thursday through Saturday period.  You can see a brief atmospheric river on Friday or Saturday.

And a significant amount of rain may fall, from Thursday though Sunday, April 4th through the 7th.  Perhaps as much as 3-5 inches across Sonoma County and the North Bay.

Of course, this may change…but if you have plans next weekend, do keep in mind that there may be lots of rain and possible heavy snow in the Sierra.  For now though, enjoy the upcoming weekend!