This wash streamer is so localised. You are looking about about 30-40 miles in width stretching SW from the Wash down to Oxford. Frustrating to watch when you are not under it, great when you are! As for later, I agree with what others have said, the wind will not have enough of an Easterly element to it for a Thames streamer. If any convection is going to spark off, then I would say the likes of Maidstone down towards Tunbridge Wells and East of that will have the best shot. Other than that, cold and dry.