I've escaped on one of the last flight before a hurricane / large storm twice now (once out of HKG before a large typhoon, and once in PVR before a milder storm).
Once you're in the air, and once you reach cruising altitude, you're fine. The real danger is landing in the storm, with low visibility and high winds.
That PVR-SFO flight was the scariest of my life; with no service and FAs strapped to their chairs for the entire 4h of the flight.