A very slow cooling trend is underway

Fall arrives in Paso Robles
Posted at 4:26 PM, Sep 22, 2021

A large ridge of high pressure pumped up interior temperature over the last several days but a trough is moving thru that flow and flattening the ridge. Then a complicated pattern takes shape with likely more cooling taking place into the weekend.

The upcoming pattern does push another ridge in from the Eastern Pacific however the Central Coast and SoCal look to be in the eastern flank of the ridge, not the place where rapid warming takes place. And at the surface, there is a low which models have been struggling to place. Right now it looks to just wobble on the CA/AZ border. That position might be able to produce some instability showers or thunderstorms south and east of us, but no real impact locally.

The trough passage to our north will likely create some northerly flow thru the area this evening and overnight. This could crank up winds across Santa Barbara County mountains, passes, and canyons. To me, I think winds generally stay under 30-35mph and right now no advisory is in place for the locally gusty winds, but don't be surprised if you experience some in typical Sundowner wind spots.

The extended forecast is also complicated, models again are not agreeing on short-term feature positioning so longer-term positions are low to moderate confidence at best. I think the slow cooling trend is still the preferred outlook and I'll go with that for now but I could see quite a bit of forecast tweaking, especially about early to middle of next week.

And, yes, fall officially began today with the equinox though meteorological fall is generally considered to begin September 1st.