Flood potential: Saturated soil in the fall could lead to spring flooding
Wet fall weather creates the potential for spring flooding.
The amount of moisture in the ground in the fall is one of three factors that contribute to spring flooding, according to Allen Schlag, hydrologist for the National Weather Service in Bismarck.
"I'm not liking what I see already," he said.
When wet ground freezes, it creates a barrier to any moisture soaking away in the spring, he said.
"If it is this sloppy when we get to freezing temperatures, the ground will be impenetrable in the spring," he said. "No ability to absorb any runoff in the spring."
Daryl Ritchison, director of the North Dakota Agricultural Weather Network, said the moisture is the result of what is likely to be the wettest September on record for the state of North Dakota.
"We've had a very wet September for most of the state," he said. "Statistically, most of the state will be wet for the fall months no matter what happens over the next months."
Jamestown received 4.8 inches of precipitation as of Sept. 29 with more rain falling on Sept. 30. The month will likely end more than 3 inches above the normal of about 2 inches for the month.
"Most of the state will have the wettest September on record," Ritchison said. "Not every reporting station but most of the state."
The NWS extended forecast for the month of October gives the eastern half of North Dakota a 50% to 60% chance of above normal precipitation with a 40% to 50% chance of above normal precipitation for the rest of the state.
Schlag said the ground is not expected to freeze solid until about the first of December. That provides about two months for the soil to dry. However, some of the factors that could dry out the soil change in the late fall.
"Once we have a frost that kills vegetation we're left with only evaporation to use soil moisture," he said. "I'm concerned with the prospect of going into November with wet soils."
While we will likely know this fall's soil moisture conditions in November or December, the other factors that make up a spring flood won't be known for another six months or more, according to Jerry Bergquist, Stutsman County emergency manager.
"It still depends on the amount of snow, the water equivalent in the snow and how fast it melts," he said. "It (soil moisture) is one step setting us up for a very interesting spring."