Updated

As voters head to the polls on Tuesday to cast their votes in the midterm elections, some may need to pack more than an umbrella in parts of the country.

While a large portion of the nation is expected to see fair weather on Election Day, the threat of severe weather, including tornadoes, is possible across the Southeast.

The National Weather Service's Storm Prediction Center said that a system moving out of Arkansas will bring an "enhanced risk" of severe thunderstorms across northeastern Louisiana into Tennessee from Monday night into Tuesday.

"The best chance for large hail, damaging winds, and tornadoes will be across southeastern Arkansas, northern Mississippi, northwestern Alabama, through Tennessee and Kentucky," Fox News Senior Meteorologist Janice Dean said Monday. "Heavy rain could cause flooding over parts of the Ohio and Tennessee River Valley."

Severe weather with the risk of large hail, damaging winds, and tornadoes is possible across the Southeast from Monday into Election Day.

Severe weather with the risk of large hail, damaging winds, and tornadoes is possible across the Southeast from Monday into Election Day. (Fox News)

Storms could target the cities of Memphis and Nashville in a state where Rep. Marsha Blackburn, R-Tenn., is facing off against Democratic opponent businessman Phil Bredesen for a Senate seat.

Further east, the National Weather Service's Atlanta office said that "strong to severe thunderstorms" could be possible in the early morning hours on Tuesday in northwest Georgia, and transitioning southeast as the day goes on.

The forecast for Tuesday in states with key Senate races.

The forecast for Tuesday in states with key Senate races. (Fox News)

"Damaging wind gusts and brief tornadoes remain the primary expected severe threats," the NWS said.

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The Peach State is where Georgia’s secretary of state and Republican gubernatorial hopeful Brian Kemp is locked in a close race against Democrat Stacey Abrams, who could become the first black woman to serve as a U.S. governor. Fox News has rated the race as a “toss-up.”

Besides the stormy South, a low-pressure system moving over the Great Lakes and an associated cold front will impact parts of the Midwest and Northeast.

"Rain and storms along the trailing cold front will keep the Northeast, Mid-Atlantic, and Southeast rainy and stormy for Election Day," Dean said.

How could weather impact voters?

Certain types of weather can be shown to have an impact on some voters in deciding whether or not to head to the polls, according to research compiled by AccuWeather.

"Weather was found to be statistically significant in influencing turnout rates by an average of nearly 20 percent," AccuWeather Data Scientist and Meteorologist Tim Loftus told Fox News.

Loftus said that researchers at AccuWeather used L2 as a resource for historical voter data, in addition to proprietary historical weather data which comprises of nearly 300 weather parameters, in order to examine how weather influences voter turnout in each state.

In Tennessee, for example, cool and damp weather has been found to deter voters from heading to the polls.

"The heaviest rain and storms should be out of the state on Tuesday which will be good news for voters," Loftus said. "However, any localized areas recovering from the severe weather just prior to Election Day may see less in the way of voter turnout as residents will likely focus on clean up and power restoration efforts."

In Georgia, storms in the state could impact likely voters, especially "weather-sensitive" groups that include African Americans, 18 – 24-year-olds, and those 65 and older. Similar rainy conditions are expected in Michigan, which could deter the same groups of people.

In New Jersey, which has a tightening Senate race between Democratic Sen. Robert Menendez and Republican challenger Bob Hugin, heavy rain may make things "quite interesting," according to Loftus. Republicans tend to fair better in the Garden State compared to Democrats when heavy rain occurs as opposed to when the weather is nice.

"So for tomorrow, historical trends indicate that Republicans will have the weather-advantage as heavy rain and storms are expected," he told Fox News.

Floridians tend to have lower turnout when its warm and muggy, as expected tomorrow, but voters in the 18 to 24-year-old range usually vote on election days that have higher minutes of sunshine, according to Loftus. The only parts of Florida that should see cloudy or rainy weather will be in parts of the Panhandle region.

In terms of how weather impacts voters of certain political affiliations, Loftus said that all depends on the state.

"For example, in Nebraska, rain deters Republicans more so than Democrats, however, I will say, for the majority of our models that we have tested, there is strong statistical significance that Republicans fare better during wet weather," he told Fox News. Loftus added that West Virginia, Rhode Island, Arizona, Indiana, and New Jersey are among the "few" states where this also occurs.

The Election Day forecast in key cities.

The Election Day forecast in key cities. (Fox News)

"Since weather may play a factor in Election Day tomorrow in certain areas, our best advice is for voters to track the weather on AccuWeather.com or download the free AccuWeather app to make the very best weather-related decisions when going to the polls," he said.

Studies have also shown that how far work or home is from a polling place could impact voter turnout if the weather isn't great, especially if people have to travel on roads that are affected by a storm.

The type of weather can also be an issue, according to Dean. Besides roads that could be icy or snow-covered, people may be wary about waiting outside in lines to vote if there is severe weather in the forecast.

The Election Day forecast in key cities.

The Election Day forecast in key cities. (Fox News)

In extreme cases, weather can cause a delay in an election. In Bay County, Fla., which was devastated by Hurricane Michael in early October, voters have been given one extra day to cast their ballots in the midterm election.  Election officials have set up voting "supercenters" because traditional polling stations and the staff to run them, just don't exist after the storm tore through the area.

"Thankfully, our forecast Tuesday, for the most part, should not dissuade too many voters, especially across the Western half of the country," Dean said Monday.

Fox News' Janice Dean and Samuel Chamberlain contributed to this report.