Mike (FWA)
Actually our radar is excellent <G>, as we have the NEXRAD overlay on our scopes. The reason that you don't vector around weather is that with NEXRAD, the weather presentation that you get is anywhere between 6 and 11 minutes old. In some parts of the US that can mean that you don't show anything, but in the meantime a level 6 thunderstorm has grown and become mature in that clear looking bit of airspace.
As to the other questions about weather ships. Lots of folks think that controllers close off arrivals and approaches. In the US that isn't really true. We keep aircraft flying until you get two pilots to agree that going in the direction they are going is a bad thing. Then we close off those arrival routes or departure routes until someone decides that it is ok again. You use a weather test ship to see if the route is good. We can see what the precip looks like and let someone go out in that area. However, quite often a pilot gets out there and doesn't like the look of the weather and decides that they are going to go somewhere else. That is why we do ONE test ship. It is much easier to deal with one person who is going to go against the flow than a lot of folks. Once a couple of weather test ships say it is fine and don't deviate, we reopen the route.
regards
Scott H. Voigt
NATCA Southwest Region
Safety and Technology Chairman