north carolina already issuing mandatory evacuation orders for parts of the outer banks. abc s senior meteorologist rob marciano is in miami to lead us off tonight. reporter: tonight, after pummeling the caribbean, the entire east coast on alert. hurricane isaias gaining strength. now taking aim at the epicenter for coronavirus cases, florida. i just signed an executive order to declare a state of emergency in every coastal county up florida s east coast. reporter: florida residents racing to prepare. when you ve got a trailer, you ve got to be concerned about everything. reporter: the coming storm also forcing coronavirus testing sites in the storm s path to close down. our sites, because they re outdoors with tents, if it were to get 40, 50-mile-an-hour winds, it would just collapse. reporter: isaias was still a two in the dominican republic, including a 5-year-old boy. flooding neighborhoods across puerto rico.