Jun 6, 2011; 6:25 AM ET
Another round of heavy rain early this week across the northern Rockies and High Plains threatens to make the ongoing flooding situation worse.
Nowhere is the threat greater than Montana, which not only is expected to have the heaviest rainfall totals tonight through Tuesday, but is already dealing with major flooding along major rivers.
Hundreds of people remain displaced from their homes throughout Montana due to flooding along the Missouri, Yellowstone and Milk rivers among others. While water levels have dropped, the forecast has residents fearing more flooding.
A wide area from eastern Idaho through northwestern Wyoming, Montana and northern North Dakota will likely receive 1 to 2 inches of rain through Tuesday, with localized higher amounts.
Complicating the flooding situation are warmer temperatures, which will promote enhanced snowmelt across the mountains, leading to increased runoff and higher water levels.
Thunderstorms embedded in the rain could lead to quicker flash flooding of streets and poor-drainage areas, especially in towns and cities such as Butte, Great Falls and Helena.
Residents are already taking action to prepare for the threat of more flooding.
Historic and sacred artifacts from a flooded Crow tribe reservation museum have already been shipped to Wyoming for safekeeping. Museum curators have been dealing with overwhelming flooding in the wake of the last storm, which brought nearly 10 inches of rain to parts of the Treasure State.
While the southeastern corner of the state could be spared from flooding this time around, severe thunderstorms and even a few tornadoes will be possible late today and tonight around Billings, extending east to the Midwest.