JACKSON, Wyo. — The National Weather Service in Riverton has issued a Flash Flood Watch for Teton County, Lincoln County, Sublette County and Fremont County from noon on Friday until 6 p.m. on Saturday due to the potential for heavy rainfall from slow-moving thunderstorms.
The Watch includes the Teton, Gros Ventre, Wind River, Salt River and Wyoming Ranges, as well as the Jackson Hole Valley, Star Valley and Green River Basin. Steep slopes and mountainous areas that have already received abundant rainfall in recent days will be especially vulnerable to flash flooding, as will burn scars and areas with poor drainage.
Monsoon moisture is moving north into Wyoming on Friday morning and will remain in place through the day on Saturday. Widespread showers and thunderstorms will develop by Friday afternoon and continue through the day, with additional showers and storms expected Saturday. Storms will be slow-moving and could produce locally heavy rainfall.
A Flash Flood Watch differs from a Flash Flood Warning in that it indicates the potential for flash flooding to occur over a region. You can think of a Watch as more of a “heads up” whereas if a Warning is issued, it will cover a much smaller area and means that flash flooding is imminent or occurring.
If you live or plan to recreate in an area prone to flooding or runoff, then be on alert and have a plan to take quick action in the event of a flash flood.
Alan Smith, Meteorologist