Hurricanes are predicted using a Saffir-Simpson Scale. This scale is used to measure the intensity of hurricane most often than not. However, it may be used to identify a hurricane as well. A hurricane is categorised based on the wind speeds.
74 - 95 mph --> category 1
96 -110 mph --> category 2
111 - 129 mph --> category 3
130 - 156 mph --> category 4
157 mph + --> category 5
Typically, the formation of a hurricane occurs when moist warm air if absorbed from the Atlantic or Pacific Ocean and rises. The moisture will then evaporate further rising and heating until the moist air is twisted and circulation high in the atmosphere.
The salt will wash into the rivers and eventually the ocean. Too much salt in a freshwater system can be deadly to the wildlife. Ultimately, it will end up in the ocean, where it will have negligible impact. The real damage will be to any river systems it's washed into.
