One area to watch is the southeastern United States, according to AccuWeather which announced Monday that Tropical Storm Rafael in the Caribbean Sea “has formed and will strengthen into a hurricane in the coming days.”

While the hurricane will not impact the United States on election day, it could threaten Florida, Louisiana and Texas later in the week and into the weekend.

“This is going to be a very stormy and impactful week for millions of Americans,” said AccuWeather Chief Meteorologist Jon Porter. “The Gulf coast of Louisiana to Florida faces the greatest risk of tropical storm impacts later in the week and into the weekend.”

For Election Day, most of Florida can expect a chance of showers. The National Weather Service in Mobile, Ala., said Monday there appears to be an “unusually large amount of uncertainty with the movement of this system later in the week.”

“Those in lines outdoors waiting to vote on Tuesday will need to be prepared for the threat of lightning and heavy downpours, which could extend from portions of Louisiana and Arkansas northeastward into the middle Mississippi River Valley and Lower Ohio Valley,” said AccuWeather Senior Meteorologist Dan Pydynowski.

While Oklahoma faced flood watches on Monday, rain is also forecast Tuesday for much of the central United States, according to Accuweather, which said as much as 8 to 12 inches of rain could fall in northeast Oklahoma, southeast Kansas and southwest Missouri. Rain is also forecast in Louisiana, eastern Texas and western Arkansas.

Morning rain is forecast for swing state Wisconsin, in addition to northern Iowa and southeastern Minnesota, while rain is forecast throughout the day in battleground Michigan.

For the East Coast, Election Day looks much dryer and warmer, with temperatures in the 70s — and even into the 80s — forecast for Washington, D.C., and New York.

Most of the West Coast is expected to be dry on Election Day, while voters waiting in lines outside in the Northwest should prepare for cold temperatures, rain and even some snow in the central and southern Rockies. Windy conditions will also make it chilly in parts of Oregon, Washington, Idaho, northeastern Nevada, northern Utah and western Wyoming.

Tuesday’s weather could have an effect on voter turnout in some states, as stormy weather “discourages voting on Election Day in the United States, especially among young adults, people who don’t vote regularly and voters who tend to support Democrats,” according to a report last month in the Journalist’s Resource.

Dartmouth College professor Yusaku Horiuchi — who has studied weather and voting in the United States — disagreed, saying early voting, mail-in ballots and this year’s divisive politics could lessen the effect of weather on Election Day.

“Given the extreme polarization of American politics, American voters may go to the polling stations regardless of the weather conditions,” Horiuchi said.

Many states with early voting have reported record turnout ahead of Tuesday’s election, including in North Carolina.

Other studies show voter turnout could depend on how hard it rains, according to Weathertrends360 Chief Executive Officer Bill Kirk, who said voter turnout drops 2.5% for every inch of rain, regardless of the party.