(CNN) -- Flood waters overturned a military vehicle at Fort Hood base in Texas, killing five soldiers and leaving four others missing, authorities said.
The soldiers' light tactical vehicle got stuck at a flooded creek, the base said in a statement Thursday night. Rescuers recovered some of the soldiers' bodies from the water downstream from the vehicle.
Three soldiers who were rescued and hospitalized are in stable condition. A search for the remaining missing soldiers continues despite a flood warning, the base said.
Severe storms have pummeled Texas, leading to a record May downpour across the state. Texas Gov. Greg Abbott has declared a state of disaster across 31 counties as more rain is expected to fall.
CNN meteorologist Chad Myers warned that saturated ground and swollen creeks, bayous and rivers could not absorb the downpour.
Owl Creek, where the vehicle overturned, regularly experiences flash floods, said Michael Harmon, the emergency manager for Bell County, Texas.
Mosquitoes also a threat
The weather could start turning around late Saturday, according to Myers. But he warned its aftermath would bring Texans a different threat: mosquitoes.
Stagnant water would likely not recede for week, and the insects were already buzzing.
"This will last for weeks," Myers said. "I don't have to tell you what that means for West Nile, for Zika," referring to two viruses spread to humans by mosquitoes.
With 7.51 inches of rain in the first two days of the month, Houston has surpassed its monthly average rainfall for June -- 5.9 inches. That follows the last week of May, which also set records for rainfall in the Houston area.
And more rain is expected.
A flash flood watch is in effect for south-central Texas until Friday morning, according to the National Weather Service. The storms could produce rainfall totaling more than 2 inches per hour and 60-plus mph winds.
"These rates, in combination with saturated soils, will result in rapid flash flooding," the weather service said.
Fort Bend County, near Houston, is experiencing flooding it called "unprecedented," the county's office of emergency management said.
Fort Bend County Judge Bob Hebert said there have been more than 558 rescues and at least 1,400 homes affected by the water.
He noted the water flowing in the Brazos River was at nearly 55 feet elevation under the Richmond Bridge -- 4 feet above the previous record set in 1994.
"That is a lot of water," he said.
He warned residents to be prepared for quickly rising waters and evacuate to recommended areas even if the water had not yet entered their homes.
"This is going to be a long event," he said Thursday. "You have to ask yourself. Do you want to spend four or five days locked in your home, surrounded by water? Do you have the food? Do you have the patience. That would be a problem for me."
500-year floods
This is the second year in a row that Texas has been hit by 500-year floods. Meteorologists and other experts point toward climate change or the weather pattern El Niño as potential culprits.
"It could just be really bad luck," said CNN Senior Meteorologist Brandon Miller. "A 500-year flood doesn't mean you will go 500 years between them. It just means it is such an extreme event that the odds of it happening are very low, therefore it only happens on average every 500 years.
"It just so happens that parts of Texas have seen them now in back-to-back years, and maybe even twice this year. "
NASA warned this year that the El Niño weather event -- characterized by warming waters in the eastern Pacific Ocean -- was one of the three strongest ever recorded.
Climate change is another possible culprit because one of the expected impacts from a warmer climate is heavier rainfall, prompting more flooding, such as the ones in South Carolina last year, Miller said.
But scientists have had mixed results in attributing the flooding to climate change, he said.