A powerful fall storm system continued to take shape in the northern plains this Wednesday afternoon, and will move slowly east through the end of the week. Very warm and moist air will be pulled northward, setting the stage for widespread rains and thunderstorms tonight into Thursday. As was previously expected, showers and thunderstorms moved across much of the Red River Valley region Tuesday night, with some locations getting over one inch of rainfall.
The low pressure system will move into western Minnesota Thursday, setting the stage for a large area of rainfall over the Red River Valley of the North. Farther to the west, heavy rains will turn to snow in the Devils Lake Basin and points west. Due to the unusually wet fall season, any rain that falls will run off into area river systems. Through early Friday, 1.5 to 2.5 inches of rain are expected from the Valley City to Fargo, north through Grand Forks and Crookston up to the Hallock and Roseau areas.
By this weekend or early next week, some river points may reach moderate flood levels. Since thunderstorms are forecast as part of the mix, there is a great deal of uncertainty as to how much rain will fall in the far southern Red River Valley. It is a result of the heavy rain on top of saturated soils; the unusual late season river flooding is forecast. Depending on how fast, and how much rain falls, forecasts may have to be adjusted higher next week.
Residents of the Red River Valley are urged to keep an eye on area rivers the next week. Visit your NOAA's National Weather Service Grand Forks web site at www.crh.noaa.gov/fgf and click on the "Rivers & Lakes AHPS" page for the latest river levels and forecasts.
Below is a graphic of the expected rainfall from Wednesday evening November 5th through Thursday evening November 6th 2008.
Stay tuned to you favorite source of weather information on this developing storm system.