LITTLE ROCK, Ark. (AP) — The remnants of Isaac dumped rain across Arkansas, left thousands of residents without electricity and carried a lingering threat of severe weather into Friday.

The National Weather Service said that once Isaac is largely clear of the state Friday, instability in the atmosphere will present a risk of thunderstorms and possible tornadoes as the afternoon heats up amid trailing storm bands.

"Any breaks in clouds, all that will do is invigorate what showers are there," weather service meteorologist Charles Dalton said.

If tornadoes form, they are likely to be short-lived and comparatively weak.

"It's not like in the spring when you totally unhinge the atmosphere," he said, adding that the tornadoes still pose a danger.

No major flooding had materialized by Friday morning, but Dalton said 3 to 4 inches of rain were still to come for much of the state. No injuries or major damage was reported Friday morning, apart from downed trees on roads.

Farmers, who struggled with a drought all summer, found themselves with too much rain as Isaac made its sloppy way across the state. Ranchers benefited the most from the rain, finally getting some water for their stock and the prospect of green grass for the animals to eat.

Row crop farmers rushed to harvest what rice, corn and soybeans they could before Isaac arrived.

Matt Winsand, manager of Cain AGRA in Lake Village in Chicot County, said he stayed open until 1 a.m. Thursday while farmers unloaded soybeans.

"With $17 (per acre) soybeans, it's important to get them in the elevator as soon as possible," Winsand said.

A flash flood warning was in place Friday morning for several south Arkansas counties as heavy bands of rain passed through the area. The weather service says Pine Bluff had received more than 6 inches of rain by 7 a.m. Friday.

Winds were between 15 and 25 mph with gusts to nearly 50 mph in places. The wind posed the greatest threat to corn and rice farmers, as the crops can't be properly harvested.

Gov. Mike Beebe said emergency crews were ready to move, but none had been summoned Thursday night.

"We've got everybody on standby. State police is on standby. Obviously the National Guard is. All of our emergency responders or people who would be expected to help in a weather event like this are on standby and prepared," Beebe said.

About 2 to 5 inches of rain was forecast for most of Arkansas, though some areas could get significantly more, said meteorologist John Robinson of the National Weather.

Even though Isaac was downgraded to a tropical depression just before 4 p.m. Thursday, forecasters said residents needed to remain aware that tornadoes can develop quickly in supercells — too rapidly for warnings to be issued.

The Storm Prediction Center in Norman, Okla., advised that there was a risk of tornadoes across the eastern two-thirds of Arkansas on Friday as new storms are expected to develop.

Entergy Arkansas reported more than 16,000 customers were without power Friday morning.

The outages were scattered across the state, with the greatest number in Pulaski County. The first area to lose power was Eudora in the far southeast corner of the state. The Chicot County Sheriff's Department said trees were down around the county just after Isaac arrived.

Despite being downgraded to a tropical depression Thursday afternoon, the storm remained organized, sending band after band of rain into Arkansas.

Even as Isaac was approaching Thursday, state residents kept an eye toward the Labor Day weekend. The Hot Springs Blues Festival announced the show would go on as scheduled on Friday and Saturday and the University of Arkansas would play its scheduled game in Fayetteville on Saturday with Jacksonville State. The school said students wouldn't be allowed to line up before 2 p.m. because of the lingering weather.

Some high school football games Thursday were moved to fields with artificial turf so the games wouldn't turn into mudfests. Other games were rescheduled.