"There has been a lot of misinformation flying around lately, so let me clarify: the Texas Department of Agriculture has absolutely no connection to cloud seeding or any form of weather modification," Miller said in a statement.

As a succession of thunderstorms fed by the remnants of Tropical Storm Barry pummeled Texas' Hill Country, tools used by the National Oceanic and Atmospheric Administration to detect extreme rainfall began “maxing out the color charts.

Flooding is the deadliest natural disaster facing Oklahomans, a threat far greater than tornadoes. In the United States, flooding kills an average of 103 people a year. Tornadoes, however, caused 48 deaths on average during the same period, according to the National Weather Service.

Weather model data shows the National Weather Service had reason to warn of higher flood risks. Still, meteorologists say the agency made reasonable predictions.

Some regions in the mid-Atlantic are also facing risks of flooding. On Sunday, Tropical Storm Chantal flooded parts of North Carolina, where more than 10 inches of rain fell near the Chapel Hill area. The Haw River, near Bynum, North Carolina, crested to nearly 22 feet, the highest crest on record there, as a result of those heavy rains.

"A lot of the weather forecast offices now are not operating at full complement of staff," said the former lead of NOAA.

Meanwhile, anguished parents waited for word on the 10 young campers still missing from Camp Mystic, which was hit hard by floodwaters.

NBC News is tracking online price levels for dozens of items at major retailers to determine when and how much they may fluctuate throughout the rest of the year.