A very moist airmass will move into eastern North Dakota and northwest and west central Minnesota on Friday. A cold front will move into western North Dakota early Friday and be located near a Brandon Manitoba to Rugby to Bismarck line by 6 pm Friday. The airmass will become very unstable late Friday causing thunderstorms to develop along and just east of the front in the mid to late afternoon. Thunderstorms will increase in coverage as the system moves through the area overnight Friday...with the system persisting over much of northern Minnesota through early afternoon on Saturday. Widespread heavy rainfall of 2 or more inches is possible in the area....but the exact location of heaviest rains and timing is still a bit unclear. Some thunderstorms may also briefly become severe with large hail and damaging winds....mainly over eastern North Dakota Friday evening. Stay tuned for later forecasts for further updates. Anyone camping Friday night should be prepared for heavy rainfall and thunderstorms.