Santa Ana, or Santana winds are a normal part of So Cal weather, happening in the fall, winter, and spring. The usual advise is that if you are anchored or moored on the East side of Catalina, leave immediately or get off the boat when: The decks are dry (no dew). ANY swell or waves (even 6 inches) come from the east. The forecast has ANY NE or E winds. Another indicator is the smog being blown out to sea from the mainland.
The high pressure in the desert flows over the mountains NE of LA, accelerates downhill to the LA basin, and continues over the ocean to Catalina at up to 45 to 60 knots. I have been on a mooring at the isthmus (Two Harbors) where we returned to our boat at 7PM to a gentle breeze from the NE. One hour later the waves were 2+feet and rising. We left ASAP and headed back to LA. Fought 30 knot winds, with closely spaced large wind waves. Eventually got back to the LA harbor. There was still the wind, but the land blocked the wave formation. For sure, if the harbor patrol is pulling the floating landing and dingy docks, GET OUT! For those who have never been to Catalina, it is like a 20 mile long rock ridge sticking up out of the ocean. The only safe harbor is Cat Harbor on the West side of the island. And even that harbor has had 60+knot winds and swells large enough to put boats and the mooring grid on the beach. Because it's the only place away from LA to go, Catalina is very popular, but can be very dangerous.
Cruising the Pacific Northwest