[RightOnTheLeftCoast]

You're right, there seem to be reserves. SO, why the warning? Perhaps the reserves graph that can be seen as the green line on http://www.caiso.com/SystemStatus.html assumes the availability of those out-of-State supplies that are being diverted?

[Dog Gone]

The alert was issued yesterday, and isn't in effect for today, so I can't really speculate how close it was. But that green line represents what California has the right to use today from all sources, and there's plenty now, for some reason.