COLUMBIA — Spring rains in the Mississippi and Missouri river valleys have brought slightly below average moisture to the region according to Mark Fuchs, a service hydrologist with the St. Louis office of the National Weather Service.
Cresting levels seen on the Missouri River in the last week brought only minor flooding to adjacent areas, while some areas along the Mississippi experienced more flooding, with submerged river bottoms and houses cut off by flood waters, Fuchs said.
Mississippi River levels on March 31 exceeded the flood threshold value by 6 inches at Hannibal, and by nearly 5 feet at Chester farther downriver according to the weather service's Advanced Hydrologic Prediction Service.
"It's kind of typical for this time of year," Fuchs said. He said the amount of flooding seen this spring typically occurs every three to five years.
The flooding was generated primarily by snow melt in Iowa, Minnesota and the eastern Dakotas, Fuchs said. The melt occurred in mid-March and was accompanied by minor rainfall, he said.
So far, spring storm season in central Missouri has been relatively quiet, said Andy Bailey, warning coordination meteorologist with the weather service. He said severe weather typically starts in mid- to late April and peaks during May.
Several weather spotters reported seeing a tornado in Randolph County on Sunday evening associated with a super-cell thunderstorm, Bailey said. The weather service had not declared the event to be an official tornado as of Monday afternoon due to conflicting reports. Video of the tornado expected from a veteran storm chaser in the next several days will be used to confirm potential tornadic activity, Bailey said.
The strength of a tornado is judged by the damage it does to various types of structures, Bailey said. He said the weakest of tornadoes, or even strong winds from a thunderstorm, could have caused the type of damage seen after last evening's storm.