Why would the PRESIDENT of the country be responsible for evacuating a city prior to a storm coming? That is well beyond his powers..
The president has no control of local transportation, of the use of the local school buses, or routing of traffic to get people out.. THAT would be the state emergency office, the city emergency office, and in turn the Mayor and the Governor.. After the fact, after the mayor and the governor had done their job (which neither did) then FEMA comes in and gives relief in the form of money and equipment. You can not expect the federal gov't to man and supply emergency provisions, trucks and other equipment outside of every city in America, so mayors and Governors alike know that in time of emergency help will come, but you will have to wait a few days for the federal help to come, until then you better have a plan in place to take of your own until they get there.