I'm posting two videos of a sandstorm hitting Kuwait. Last year in the Middle East we arrived in the middle of one of these, but it wasn't quite this bad. Its all in Arabic, but give it at least until the 4 minute mark when you can see how ridiculous this is.
Here is another one- I'm not sure if you can click on this one or not. It's a little bit different perspective. Perfect daytime visibility to 0 visibility in only a few minutes.