The gap is pointed in the wrong direction — it’s a funnel on the west side, but mostly open on the east. So you either need to get particulate matter (ie heavier than air) over a barrier taller than the Appalachians, or the wind from that point needs to be lowest energy source — a strong pressure gradient around that bends from northwest to due west. The first is unlikely because most conditions that cause Santa Ana winds come with a strong inversion layer. The second is less likely due to the synoptic situation — and honestly mesoscale too. The storm tracks driven by the jet stream rarely go far enough south for a strong high pressure to be sitting over Arizona or Sonora. Over Nevada or Utah, you get winds from the Great Basin — the wrong direction. But because Arizona is so hot, the rising air keeps pressure a little lower. Low pressure over the San Gabriels or further north will just pull air through all the canyons and passes — not a very long fetch.

It’s definitely a risk to Palm Springs and El Centro. LA is just a breeze too far.