Lowell,
Very interesting analysis. When you first mentioned this some months ago, I figured you had been experimenting with Don's raw garlic and onion sandwiches, but in deference to the folks down the road, maybe had a few too many Coors chasers...

One thing that made me wonder whether this was a reasonable preposition is that I know from experience (similar to yours, execpt I managed to avoid the lightning) that you can frequently get hurricane force winds at higher elevations in the Cascades, generally from the west, and wouldn't you see this effect in the data, maybe on a more frequent basis than hurricanes on the east coast.... But maybe your back of envelope analysis, and looking at some of the differences between hurricanes (which put an "abnormal" strain on the continent) versus more of a "tradewind" effect of Pacific Storms help explain why this would create observable anomalies in the GPS/LOD data. The continent is probably "used to" winds from the west, but a strong hurricane would (I think) put an abnormal "northerly" force component to the eastern portion of the continent. The weight of the water from a storm surge would possibly also contribute.
Very interesting... thanks for sharing,
Bill