North Dakota Too Cold To Flood

When the Red River crested at Fargo-Moorhead on Tuesday, it was 7 feet below the peak that experts had considered very possible only two weeks before.

That was a break for residents who have had to fight off five of the eight highest crests in history since 2001. But it also exposed blind spots in a system of flood prediction that river cities rely on in mounting their annual preparations.

It also generated criticism in Fargo that the city spent more time and money — about $3 million altogether — than necessary to protect against the high water. The mayor and others, however, defended the forecasters and the steps taken.

Conditions this spring were “climatologically unprecedented,” said National Weather Service hydrologist Greg Gust, who is based in Grand Forks, N.D., along the Red. In most years, when the snow begins to melt and rivers break free of ice, the landscape along the Red remains frozen and impermeable, allowing meltwater to run quickly across fields and ultimately, into the Red.

But this year, because the cold extended into late April, the ground thawed quickly under high sun and soaked up the snowmelt, limiting runoff. Dry weather also helped. The delayed cold wasn’t something hydrologists could put into their models, Gust said, because it wasn’t part of the climate record; the 2013 crest was the latest since 1887.

Late, lower-than-feared Red River crest at Fargo puts spotlight on forecasting | StarTribune.com

h/t to Tom Nelson