The antenna was totally destroyed, with half the elements broken or irreparably bent. I was surprised just how fragile those things are; I was able to pull the elements off as easy as plucking a chicken. Several of the elements had pierced into the asphalt roof material, a couple of them several inches. I cut the remaining guy wires and the antenna and rotor wires, and lowered the antenna to the ground.
I headed over to the nearest Lowes and bought a tube of polyurethane asphalt sealant, then climbed back up onto the roof and squeezed the oozy stuff into the holes. The sealant has an odd smell, almost like chocolate, and it was thick and dark like frosting. I wonder how many kids have tried to eat this stuff.
Now I had to prepare the remains of the antenna for disposal. The mast itself was made of steel, and was in relatively good condition. The center section had a generous coating of rust, but it was still quite solid. The other segments appear to have been galvanized, and had only minimal corrosion. It could have easily stood for another 30 years if it hadn't been for the guy wires. The wires themselves were in fair shape, quite rusty, but still reasonably strong. All the connectors on the mast had rusted solid, but were still strong enough that it took quite a bit of work with a hacksaw to cut through them. I cut through the bolts holding the rotor onto the mast, and that also separated the antenna. I then plucked the remaining elements off the antenna, then sawed through the relatively soft aluminium until I had pieces small enough for the trash.
I haven't done anything with the mast yet. If I dispose of it, I'll have to try to saw through the thick steel several times to cut it into pieces small enough for the garbage can. The connector points are too badly rusted to unscrew, but the shaft itself seems in fairly good shape.
At least the wind instruments that were attached to the mast were completely unharmed, though they are now homeless. I need to come up with some way to mount them at least 10 feet above the peak of the roof. I can either salvage the old mast, perhaps shortening it a bit, or try to built a new mast, perhaps of light but strong PVC sewer pipe. Or I can purchase a new tripod mast specifically designed for this weather station, with platforms and connection points so that all the instruments can be mounted in one place. The biggest problem is I'm not sure how to mount something to a hot-mopped asphalt roof without potentially compromising its waterproofness.
After getting everything cleaned up I almost broke my ankle stepping into a damn gopher hole. If I ever see one of those things, I'm soooo going to blow it's head off with a shotgun.