According to the UN, the storm victims are not refugees. They also are not internally displaced persons, whom the United Nations High Commissioner for Refugees (UNHCR)
describes this way: “Like refugees, they are hapless civilians often
caught up in an endless round of civil conflict or persecution.”
“Evacuee” seems to be the best term, given the expectation that many
of the persons now around the country will, or at least will be able
to, return to home.