Next Storm: Flooding Rain With Some Mountain Snow

Posted at 6:47 PM, May 16, 2018
and last updated 2018-07-05 14:57:39-04

A new storm system triggering thunderstorms, and additional snowmelt will compound the flooding situation over the next several days.  A FLOOD WARNING continues for Lewis & Clark County, but also for the Sun River.  The town of Sun River could be hit especially hard where “significant inundation” is possible in town.  Highway 200 is also expected to have water on the road.  Areas in Helena and Lincoln will also see the floodwaters rise, likely hitting areas that have already been hit hard.  Thunderstorms will quiet down overnight into Thursday morning before picking back up Thursday afternoon.  Storms could produce locally heavy rain and flooded areas could have water quickly rise.  Highs will be cooler, in the 60s and 70s.  Friday, a steady rain will develop over much of Montana.  Colder air moving in will allow snow levels to drop below 5000′ in some locations, especially along the Rocky Mountain Front and near the Continental Divide.  Highs on Friday will only be in the 40s and 50s, 30s in the mountains.  Steady rain over the course of several days will likely create rising creeks, streams and rivers later Thursday through Friday.  Some showers will continue on Saturday as well, and water will likely crest over the weekend.  Saturday afternoon will have some clearing for the northern half of the state.  Sunday will start out dry, but scattered thunderstorms will develop over the mountains in the afternoon.  Thunderstorms are likely to be scattered through the state on Monday, Tuesday and Wednesday of next week.  The wet weather with continued snowmelt means flooding will be an issue potentially through Memorial Day Weekend.

Curtis Grevenitz

Chief Meteorologist