The National Weather Service said the heaviest rain should fall from Cooperstown, N.D., through Grand Forks to Waskish, Minn., and the heavy rain band will be about 100 miles wide, though the storm track could shift a bit to the north or south.
Because some areas still have nearly saturated soils from flooding earlier this spring, rainfall may run off and cause some area rivers and streams to rise again.
Ponding of water in poorly drained areas is also likely, and people living near rivers and streams should monitor this situation. Forecasters urged people to stay tuned to the Weather Service to listen for updates and later statements on this heavy rain event.
Forecasters said the slow-moving low-pressure trough causing the rain will move out of the Rocky Mountains tonight. Strong low-level winds will bring abundant moisture northward from the Gulf of Mexico, helping to fuel the heavy rainfall. The system is expected to exit the region by Tuesday
Showers and thunderstorms will move in tonight, with heavy rain possible after midnight and during the day Monday. Lows tonight will be in the upper 40s, with a 90 percent chance of precipitation.
The rest of the week looks to be mostly nice, with highs in the mid-60s on Tuesday, the low to mid-70s on Wednesday and Thursday, the upper 60s on Friday and the low to mid-70s on Saturday. There's a slight chance of showers and thunderstorms Friday, forecasters said.
Source : http://www.grandforksherald.com/content/heavy-rain-expected-tonight-monday