Weather Alert - Upper Green River Basin
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WWUS85 KRIW 221501

Special Weather Statement
National Weather Service Riverton WY
901 AM MDT Tue May 22 2018

Star Valley-Salt River and Wyoming Ranges-
Upper Green River Basin Foothills-Upper Green River Basin-
South Lincoln County-Rock Springs and Green River-Flaming Gorge-
East Sweetwater County-
Including the cities of Afton, Alpine, Star Valley Ranch, Thayne,
Pinedale, La Barge, Big Piney, Farson, Kemmerer, Cokeville,
Rock Springs, Green River, and Wamsutter
901 AM MDT Tue May 22 2018

...Strong Thunderstorms possible today...

An approaching weather disturbance will help fire showers and
thunderstorms by late this morning, continuing through this
afternoon hours before lifting northward early this evening. Some
of these storms may contain pea to marble size hail, strong wind
gusts and heavy rain. Be alert and listen for the latest
statements from your National Weather Service office in Riverton.
If you encounter any severe weather, relay it to your local law
enforcement office or to the National Weather Service at 1 800 211

FGUS75 KRIW 211513
Hydrologic Outlook
National Weather Service Riverton WY
913 AM MDT Mon May 21 2018

...Accelerated snowmelt at the 9,000 to 10,000 foot elevation
Friday through Sunday...

...Significant rises in creeks and streams during the
Memorial Day Weekend...

There is still 20 to 30 inches of snow water equivalents (SWEs)
at the 9,000 to 10,000 foot elevation. The snowpack has ripened
considerably in the last week to 10 days due to mild temperatures
and recent rainfall.

Afternoon mountain temperatures at the 9,000 foot elevation are
expected to warm to near 60 for Friday--and into the lower to
middle 60s Saturday and Sunday. Morning low temperatures are
forecasted to be at or above the frost temperature of 37 degrees
Friday through Sunday.

Increased snowmelt at the 9,000 to 10,000 foot elevation Friday
through Sunday will cause significant rises in creeks and streams
during the Memorial Day Weekend.

Any rainfall on Sunday and Memorial Day will greatly increase creek
and river levels due to a combination of rain and snowmelt runoff.

During active snowmelt runoff, mountain creeks and streams are
at their highest levels during the late afternoon/early evening
hours. Crossing creeks and streams during that time is highly

Graphical forecasts are available at:
Visit weather.gov/riverton and select the rivers & lakes tab for
graphical forecasts and additional information.


Tropical Watch