Wyoming Unknown Hydrologic Outlook | Effective 09/18/2026 09:20

Headline: 
Hydrologic Outlook issued September 18 at 10:20AM MDT by NWS Riverton WY
Event: 
Hydrologic Outlook
Urgency: 
Future
Effective: 
September 18, 2026 - 9:20am
Expires: 
September 19, 2026 - 11:00am
Description: 
ESFRIW A wet weather system will support periods of showers and thunderstorms across Wyoming Friday, Saturday, and Sunday. This weather system is funneling abundant tropical moisture into the state. Given this anomalously high moisture, many thunderstorms will feature heavy rainfall, possibly leading to localized flooding. Poor drainage areas, urban areas, and steep terrain will be the most susceptible locations for this isolated flooding. Many locations could see rainfall totals anywhere between 0.75" to 1.75" through Sunday afternoon, with a majority of this rain falling quickly in thunderstorms. Remember, if you encounter a flooded roadway, turn around don't down!
Area Description: 
Big Horn, WY; Fremont, WY; Hot Springs, WY; Johnson, WY; Lincoln, WY; Natrona, WY; Park, WY; Sublette, WY; Sweetwater, WY; Teton, WY; Washakie, WY
Forcast Office: 
NWS Riverton WY
Sender: 
w-nws.webmaster@noaa.gov