NWS Western and Central Wyoming

… Wyoming entering 9th consecutive water year with at least moderate-severe hydrologic drought conditions…

… Above normal precipitation totals along the Tongue, Powder and Belle Fourche River Basins water year 2007…

... Extreme hydrologic drought eases over the Upper Green, Lower Wind and most of the Upper Snake River Basins…

…Lowest September reservoir storages for Pathfinder and Seminoe Reservoirs in the last 30 years…


The Tongue, Powder, and Belle Fourche River Basins received above normal precipitation for water year 2007. The Powder River Drainage had 108 percent of normal precipitation for the entire water year.  All other major basins across Wyoming had below normal precipitation totals during water year 2007.  Both the Little Snake and Lower North Platte Watersheds had only 79 percent of normal precipitation for water year 2007.  

Wyoming has entered the 9th consecutive water year in which at least moderate to severe hydrologic conditions have affected at least half of the state.  Wyoming entered water year 2008 with the western half of the state remaining in severe hydrologic drought; and the majority of eastern Wyoming continues to experience moderate hydrologic drought conditions.  Northeast Wyoming continues to be relatively drought-free.  The good news is that Wyoming, for the most part, is entering water year 2008 without extreme drought conditions to contend with—only a very small area of the upper Snake Watershed remains in extreme hydrologic drought.

Current calendar year rainfall totals across Wyoming vary from 124 percent of average at Casper to only 71 percent of normal at Lander.

The end of the irrigation season left reservoir storages well below average for Wyoming’s major reservoirs. Boysen Reservoir was only 53 percent of capacity by the end of September; and Pathfinder Reservoir was only 17 percent full by late September.   In fact, September reservoir storages for Pathfinder and Seminoe Reservoirs continue to be the  lowest in 30 years.

The latest drought outlook through January 2008 indicates that most of central and western Wyoming will see some improvement in current drought conditions.



To view the complete monthly Wyoming drought information statement with graphics, please refer to:


For even more drought graphics,  please go to:



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