demonstrators are rallying in solidarity for victims of police brutality on the weekend hong kong leader kerry webb has warned escalating tensions in the city could put on a quote path of.

webb, thanks for that. >>> let's go to florida where nbc's kerry sanders is on the ground.the story where you are? >> we heard janessa talking about the strength of the hurricane. one of the big questions is how powerful this hurricane could grow. category 4, maybe a category 5? now the knnoaa working in co conjunction with the national hurricane center has some new pieces of technology to give them instantaneous information. this looks like a tornado. this is an autonomous glider, it goes out and dives down to the water. it doesn't even have a battery on board to cause it to move forward it swims like a fish. it has a bladder. when the bladder contracts, it uses gravity to go down. it is gathering the levels of the water so that you can understand the density of the water out there. most important is the temperature. that temperature, the warmer it is, the more powerful the hurricane can get. when that glider comes back to the surface, it transmits back the information so that the scientists at the national hurricane center can say okay, this is what we think will happen w