SE winds from ocean buoys the East Bay .

by Mike Godsey, mike AT iwindsurf.com

I got a text from Gorge sailor Greg M. at 2:30PM today Tuesday Sept. 13

Just landed at SFO after circling for an hour. And a westerly approach after being told the wind was easterly. Looked south to me. Wtf did you do to the wind here ?
Sent from my iPhone

Unless you have been following my and Ben’s extended forecasts for the last 4 days you are probably puzzled by these weird S to SSE winds.

Yea I know that we sometimes get SE winter storm winds. This usually happens when a Cut-Off Low at ≈ 18,000 ft. sets up in the right position near the Bay Area.

So what is causing SE winds in Sept?

Good guess! Yes it is a Cut-Off Low. These critters do not occur in our waters in Sept. Welcome to Global Weirding!

This animation starts with the counter-clockwise spinning low pressure focused just west of the Bay Area as modeled at 3PM today. Sort of looks like a surface eddy huh?

But as we head aloft from the surface to 5500 meters you can see that the cause of the low pressure is a Cut-Off Low over the California and Nevada.  Why is the Cut-Off Low not centered over the Bay Area while the surface low pressure is just to the west of us? Think about friction from topography at the surface compared that 3 miles up.