If a hurricane is heading for the Gulf of Mexico it might be a good time to buy some energy shares. If the hurricane veers off at the last moment it probably would be a good idea to sell them quickly.
For weather I like using these two sites -
The first one gives you a quick and dirty on hurricane forecasting. The second shows you the data from various weather satellites and you can draw your own conclusions. I use the first to get my early warning and the second to stay in touch on a near real-time basis.