Wind Farm Tornado: Multiple Vortices
[Part 3 of 5] The main cone got fuzzy for a short spell, with ragged but visually fast-whirling condensation vortices on both sides. Positioned along the east (left) rim of the main mesocyclone, and eventually shunted eastward by a segment of the rear-flank downdraft, the tornado translated at a very oblique angle to the alignment of the facility. This kept some part of the wind farm in the circulation for a few minutes, exposing multiple turbines to a potentially destructive strike. A couple of the towers already were disabled prior to the tornado (presumably due to non weather-related malfunction), and their blades didn't budge as far as I could tell. Most of the turbines were active, however; and they kept spinning at no more than a fixed, constant maximum rate throughout the ordeal. This is how they should work at excessive wind speeds, a category that certainly includes tornadoes. Mechanical brakes prevent the blades from spinning so fast as to damage the internal machinery. In this case, they worked. I can't claim they would for a truly violent tornado, however--one that indeed might topple turbines and rip blades loose.
10 NNW Meers OK (7 Nov 11) Looking SW