Erik Burgess, Published October 14 2013
It's too soon to say whether recent heavy rains will lead to big spring flood
Parts of the region have received two to three times their normal precipitation for this time of year, according to the weather service, and the southern Red River Valley can expect 2 to 3 more inches of rain through today, prompting flood watches for Cass and Richland counties in North Dakota and Clay and Wilkin counties in Minnesota.
River flood watches are in effect for the Red River at Wahpeton, N.D., and Fargo, for the Wild Rice at Abercrombie, N.D., and for the Buffalo River near Dilworth and the South Buffalo near Sabin, Minn.
The weather service anticipates the Red River could reach 22 feet in Fargo by Saturday. Minor flood stage in Fargo is 18 feet.
WDAY TV Chief Meteorologist John Wheeler said fall rains are only one piece of the spring flood puzzle.
“The more rain we get in the fall, the more it adds to concern into the winter,” Wheeler said, “but going into the fall wet does not guarantee a spring flood.”
He pointed to this past spring, when there was still the potential for a major flood despite a very dry fall in 2012.
National Weather Service meteorologist Jennifer Ritterling said a number of factors play into the spring flood picture, including how much snow we get, how fast it melts and if there is additional rain or snowfall on top of the melt next spring.
“The amount of precipitation we have in the fall does matter,” she said, “but it’s only one of many factors.”
If these heavy fall rains freeze in the topsoil too quickly and aren’t given time to soak deeper into the soil, there’s a greater chance for spring rains to run off into the river and flood, Wheeler said.
That’s what happened in 2009, when late fall rains froze too quickly and the topsoil became “frozen cement,” he said.
“When we started getting heavy rains (in March 2009), it was like it was running off concrete,” Wheeler said. “There was just no way that the spring rains could soak in at all.”
But as long as we don’t have any more heavy rainstorms this fall, Wheeler said, there still is time for the water to soak deeper into the soil because the ground doesn’t become totally frozen hard until sometime in November.
Ritterling said there hasn’t been a hard overnight freeze in Fargo yet. The coldest it’s been was when the mercury dipped to 33 degrees on Sunday morning.
She said to expect a hard freeze – 28 degrees or colder – later this week or into the weekend.
“(Wet fall weather) doesn’t become a major concern until we start getting snowstorm after snowstorm,” Wheeler said. “And if that doesn’t happen, it probably isn’t a big deal.”
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Erik Burgess at (701) 241-5518