Grand Teton National Park, Wyoming
Regional Weather Alerts
| Alert: | Hydrologic Outlook |
| Area(s): | Big Horn, MT; Carbon, MT; Golden Valley, MT; Park, MT; Stillwater, MT; Sweet Grass, MT; Wheatland, MT; Yellowstone, MT; Sheridan, WY |
| Effective: | 2026-05-10 @ 4:45 pm |
| Onset: | 2026-05-10 @ 4:45 pm -> 2026-05-13 @ 6:15 pm |
| Severity: | Unknown |
| Certainty: | Possible |
| Urgency: | Future |
| Issued By: | NWS Billings MT on 2026-05-10 @ 4:45 pm |
| Headline: | Hydrologic Outlook issued May 10 at 3:45PM MDT by NWS Billings MT |
| Description: |
ESFBYZ Warm temperatures reaching 10 to 20 degrees above normal will enhance snowmelt in the mountains this week, resulting in significantly higher flows on area waterways. Flooding is not expected at this time due to marginal remaining snowpack in the middle elevations between 6000 and 8000 feet. Rivers such as the Yellowstone and Clarks Fork of the Yellowstone are forecast to see flows double the current flows by the end of the week. Smaller streams and creeks flowing out of the mountains will experience rises first this week, with larger rivers and streams further downstream seeing increases by the end of the week. Those with interests along foothills waterways should be prepared for higher water levels this week, and move property and livestock away from rivers, streams, and low lying areas. Runoff may fill culverts, ditches, and storm drains causing water to flow over foothills roadways potentially causing damage. Do not drive over flooded roadways, Turn Around Don't Drown. Recreationists in the mountains and foothills should be prepared for changing conditions and use extra caution when near waterways. Flows will be faster, and the water is very cold. Stay tuned to the forecast. Please report any flooding to local law enforcement and have them relay the report to the National Weather Service. |