WILLMAR - Persistent cold and snow and a forecast for more snow - a lot more - has led to an increased risk for spring flooding in west central Minnesota, according to the National Weather Service in the Twin Cities.
The new advisory issued Thursday warns that there is now a greater than 50 percent probability for reaching major flood stage along much of the Minnesota River, including Montevideo. The new advisory comes two weeks after the season's first advisory on Feb. 21. The last two weeks saw below-normal temperatures and more snow, adding anywhere from a half-inch to 1 inch of water content in the snowpack.
There is now a snowpack holding 2.5 to 4.5 inches of water across most of Minnesota, with some headwater areas in Minnesota holding 5 to 6 inches of water. The snowpack ranks in the top 20 percent - in some areas the top 10 percent - of historic snowpack depth.
A major snowstorm is expected to add anywhere from 8 to 12 inches of heavy, wet snow to the area this weekend. A mix of snow and rain is possible Tuesday.
The heavy snowpack, along with 2 to 4 feet of frost depth and a high soil water table, all increase the prospects for flooding.
Current projections indicate the greatest risk for flooding will occur in early April.
The weather service noted that the severity of the flooding will depend on weather conditions for the remainder of the month and into April. The best-case scenario would include near normal temperatures and little rain, with daytime temperatures in the 30s and 40s and below freezing at night.
Worst-case scenario would be an extended period of warm, wet weather with temperatures in the 50s and 60s in the day and lows in the 40s with high dew points, according to the weather service.
In Montevideo, the major flood stage is 18 feet of river elevation. The Minnesota River is currently at 7.6 feet in Montevideo. The highest river crest recorded in Montevideo was 23.90 feet on April 6, 1997.