Jets away can fly when nessary. There made to do that sort of thing.
Except we're talking about the B-2 fleet which has a mission capable rate of ~40 percent, meaning at any one time only about eight of the aircraft are ready to be flown. If you don't have enough crews on alert ready to fly on very short notice, along with ground personnel, most, if not all of those birds are going to stay on the ground. Maybe the 509th is prudent enough to have enough pilots in the ready room suited up watching the Weather Channel 24/7 in case inclement weather develops but I doubt it.