I know this is old, but we have a lot of towers in the area, the NOAA broadcast was on an existing tower. We also have the ISP (Iowa State patrol) communications tower and I'm not sure what all. The tower supposedly suffered Ice damage, not sure why it took so long to repair. The tower itself remained up, so likely just ice bridge damage.I'm fairly certain that NOAA had lost a transmitter/tower site, and had to relocate to a new facility opportunity. I'm certain that NOAA doesn't have their own tower for this site- they're leasing someone else's.
If you look closely, you'll see that Pottawattamie County's transmit site is south of Avoca and Walnut, Iowa, which is in the middle of a rapidly-expanding wind farm. As such, there's lots of building going on, and crane service for any sort of high-lift is insanely expensive, and LONG on scheduling. If they had to wait for some other tower to be built, or even if it was an existing tower and they were waiting for a crew, that's why it took 'so long'.