Montana Unknown Hydrologic Outlook | Effective 06/27/2026 11:25

ESFMSO What: Widespread moderate rainfall over a prolonged period of time. Storm total amounts between 1 to 3 inches for valleys and 2 to 4 inches for the mountains. Where: Flathead and Lake Counties in northwest Montana, including Glacier National Park. Timing: Beginning Sunday afternoon, continuing through Monday night. Significant rainfall totals will bring potential for rapid rises on streams and creeks, rock and debris slides and runoff issues in poor drainage areas. Those recreating in the backcountry should take caution on backcountry roadways for falling debris. If camping, be mindful of where you park your RV or pitch your tent. Avoid setting up near water's edge, as streams and reservoirs could rise rapidly and flood your site.