That prediction only gives a general idea of where the storms might be heading in a week. You'd be amazed how quickly the predictions change on a day to day basis.
What you need to do is check the radar on a daily basis and pinpoint the location where it gets the most rain and is the most intense on that specific day. These desert storms appear and disappear within a 1-3 hour time frame, and it is very easy to miss if you're not constantly checking.
Here is the map of the radar from last week where I drove out and found N. cockerelli. The map took me out to a dirt road out in the middle of nowhere in the desert. Took multiple screen shots of the area before I left, which helped me ascertain where to drive out to and park. Once I got to the general area, I would shovel some dirt up and get an idea of how wet the ground was. If it wasn't wet enough, I'd drive down further til there was a spot where the ground was soaked several inches deep.
So when you say you are going to the 10 and cottonwood springs next week, that is not going to guarantee a find. Unless that whole area got a torrential thunderstorm all day long, you will have to be more exact. You have to look that specific day, and maybe down to the specific hour, and then plan accordingly when and where to drive out to.
Part of it is also a gamble, because that area may have already had flights as well. The night I drove out after those storms, nothing flew. It was too cold, actually. So I decided to stay another night and then everything flew.
You have to act quick. It hovers from 100-110 deg in the socal desert right now. By the third day, the ground surface will have nearly dried up and there will be no trace of rain.
Edited by nurbs, July 16 2017 - 3:16 PM.