Two journalists were killed as Subtropical Storm Alberto swept ashore hundreds of miles away, with forecasters warning the system would bring more heavy rain to the South on Tuesday.

Alberto, the first named storm of the hurricane season, made landfall on Florida's Panhandle on Monday afternoon, washing out the unofficial start of summer.

In Polk County, North Carolina, the two television journalists were killed when a tree fell on their vehicle on U.S. Highway 176 near Tryon, state Trooper Rico Stephens said.

Their station, NBC affiliate WYFF of Greenville, South Carolina, identified them as anchor Mike McCormick and photojournalist Aaron Smeltzer.

WYFF News 4 anchor Mike McCormick and WYFF News 4 photojournalist Aaron Smeltzer died Monday when a tree fell on their SUV. https://t.co/VZZKA6K6qq All of us at WYFF News 4 are grieving. We are a family. pic.twitter.com/IQmZ6prUIH — WYFF News 4 (@wyffnews4) May 28, 2018

"All of us at WYFF News 4 are grieving," the station said in a tweet. "We are a family."

McCormick and Smeltzer were reporting on the fringes of the large system whose core made landfall on the northern Gulf Coast.

Alberto had weakened to a subtropical depression by 11 p.m. ET Monday and was centered about 50 miles west-northwest of Dothan, Alabama, according to the National Hurricane Center in Miami. The storm had maximum sustained winds of 35 mph.

Though the storm had weakened, forecasters warned it was capable of potentially life-threatening flash floods as it spreads over Alabama and large areas of Georgia, Tennessee and the Carolinas.

"The main threat will be heavy rain and flooding along its path," Weather Channel meteorologist Kevin Roth said early Tuesday. "It's moving across the South — Alabama and Tennessee — today."

Roth predicted some areas could get up to five inches of rain.

Earlier Monday, Alberto rolled up big waves and tides along beaches of the northern Gulf Coast. Lifeguards posted red flags along the white sands of Pensacola Beach, where swimming and wading were banned as Alberto disrupted long holiday weekend plans for millions.

Harrison Westwood, 4, and his father Ben watch waves crash near the beach as Alberto approached Pensacola, Florida, on Monday. Dan Anderson / AP

The storm also forced some Memorial Day tributes to be cancelled across Florida's Panhandle.

In Cuba, where Alberto's outer bands dumped about a foot of rain — causing rivers and reservoirs to overflow — the storm shut down railroad service, an oil refinery and parts of the country's national highway, according to state television and Cuba's National Meteorological Institute.

About 20,000 people were evacuated across the island.

Alberto comes at the same time as a separate storm system that raked the mid-Atlantic over the weekend and deluged the community of Ellicott City, Maryland, which was swamped by a river that rose by 17 feet in just two hours.

Recent heavy rains in the Southeast could also make flooding worse in some areas of Florida and through the Carolinas where the ground is saturated, according to the National Weather Service.