A monster blizzard this week, which crippled the eastern half of North Dakota with very strong winds, heavy snowfall and blizzard conditions, has further increased the risk of Spring flooding along the Red River. The National Weather Service (NWS) issued an updated flood forecast for the U.S. portion of the Red River basin Friday.
Heavy snow in February, followed by additional heavy snowfall and high water quantity snows in March has led forecasters to predict 2019 will be a Top 10 runoff year. Significant overland runoff and rural flooding is expected in most areas of the Red River Valley, but less so in the northeast corner of the state. Since December 1st, snowfall has run from 100 to 200% or normal, least in northeast North Dakota, and most from north central Minnesota into the central and southern Red River Valley.
According to data released by the NWS, there is a 95% chance the Red River will reach major flood stage at Fargo of 33.8 feet (40.84 feet is the flood of record set in 2009). At Grand Forks there is a 90% chance the Red will reach major flood stage of 47.5 feet (flood of record is 56.7 feet). At Pembina there is a 95% chance the river will reach major flood stage of 51 feet (flood of record is 54.94 feet in 1997).
Meanwhile, the NWS is not expecting significant flooding along the Pembina River through Walhalla and Neche, with a 95% chance of below average flows at both points.
From a weather perspective, the flood forecast indicates the next two weeks could bring “pleasant thaw weather”, but notes there’s “no guarantee that the end of March and beginning of April will cooperate.”
It’s expected Manitoba’s next flood forecast will be issued in the next couple weeks.