I think it was still misting then, but the weather didn't seem that bad to me (looking out the window of my apartment at the time, listening to the news of Bush being driven to the White House.) I left home in my car shortly after 1 PM, and had no trouble driving.
I suspect the whole excuse of the weather is a smokescreen for security reasons. Remember those "anthrax" searches in the Catoctin Mountains the past couple of weeks. Somebody commented on a thread about seeing F-16's headed in the direction of Camp David at the time of Bush's return. Bush got to Camp David somehow on Friday. Presumably he was driven. Why couldn't Blair go that way too?
Speaking of questions about Saturday morning, not only was Card allegedly watching NASA TV at Camp David around 9 AM. The Joint Chiefs were able to get together for a domestic incident meeting by 10 AM or so. I commented on a thread at the time how strange that seemed to me.
Getting them all together at one time is a major scheduling feat normally. Were they in Camp David or the Pentagon or where for their meeting?