Updated at 4:38 p.m. ET
Storms continued to move through Texas and Oklahoma, bringing tornadoes and dumping torrential rains that led to deadly flooding.
Authorities in Oklahoma say four people have died as a result of the storms this weekend. During a press conference, Houston Mayor Annise Parker said authorities had recovered the bodies of at least two people in that city. According to media reports, four other people were killed in weather-related incidents in Texas and at least 12 people are missing.
President Obama called the flooding "terrible," and said he spoke with Texas Gov. Greg Abbott this morning.
"I assured Gov. Abbott that he could count on the help of the federal government," he said. "We have FEMA personnel already on the ground. They are coordinating with Texas emergency management authorities and I will anticipate that there will be some significant requests made to Washington. My pledge to him is that we will expedite those requests."
Obama also signed a disaster declaration for Oklahoma.
" 'It had been raining here for weeks, a lovely wet spring after years of drought. The ground was saturated,' said [Louie Bond], a magazine editor and former editor of Wimberley's newspaper. 'The cypress trees along the river are stripped down to bare toothpicks.'
"Wimberley and nearby San Marcos, a pair of Blanco River towns off the Interstate 35 corridor linking Austin and San Antonio, appear to have been the hardest-hit towns in the United States. But in Ciudad Acuña, a Mexican city of about 140,000 on the border due west of San Antonio, a tornado that leveled blocks of buildings at sunrise Monday killed at least 13 people.
"In Oklahoma, weekend storms killed two people: a firefighter in Claremore, near Tulsa, who was swept into a storm drain Sunday, and a Tulsa woman who died Saturday after her automobile hydroplaned on a highway."
The Weather Channel reports that some parts of Texas, which if you remember were suffering through a drought not long ago, have received more than 20 inches of rain this month.
Houston got more than 10 inches of rain last night. The Houston Chronicle reports that caused water to pool in city streets and even on highways. Interstate 10, a major east-west thoroughfare in the city was closed this morning and Twitter users sent pictures of cars apparently floating across Interstate 45:
Parker said that while large parts of the city were "high and dry," some highways and neighborhoods were still unappeasable. The Houston mayor called on residents to stay home if they could.
Forecasts call for this weather pattern to continue.
The Weather Channel reports:
"A southward dip in the jet stream has been locked in place over the western states, allowing it to launch disturbances into the Plains. Those disturbances provide the necessary lift in the atmosphere to trigger thunderstorm development as they intercept a warm, moist air mass in place near the surface of the earth.
"Thunderstorms Tuesday will not be as widespread as they were over the weekend in Texas and Oklahoma, but a few severe storms may fire up, and any rainfall will run off due to the saturated soil.
"Unfortunately, the large-scale pattern appears poised to snap back into its original configuration by late in the week, setting up yet another round of heavy rainfall for the last few days of May. It's possible that final totals for the month of May could top 30 inches in parts of Oklahoma, and it appears likely that at least one location will break the official all-time May rainfall record for the entire state, which is 23.95 inches in Miami, Oklahoma, in May 1943."