Wyoming Drought Information and Graphics--Updated January 28, 2009

 ...Moderate hydrologic drought persists across southwest Wyoming--Upper Bear and Lower Green Basins…

…Normal to above normal precipitation totals for rangelands/basins across the northern half of Wyoming for current water year 2009 (October - December 2008)---Below normal precipitation totals for southern rangelands/watersheds…

…Near normal mountain snowpack averages across Wyoming….

…Reservoir storages across Wyoming continue to above water year 2008 storages…

3 key ingredients define the overall drought picture for Wyoming:  Rangeland Precipitation---Water Supply---Mountain Snowpack--

Rangeland Precipitation---
Precipitation across Wyoming’s pasturelands/rangelands during the current water year 2009 (October - December 2008) was near normal to above normal across the north and below normal across the south.   Precipitation across the major river basins across Wyoming was also near normal to above normal across the northern areas and below normal over southern areas.
35 to 50 percent of the water year’s total precipitation across the majority of Wyoming’s rangeland/pastureland areas occurs in the spring (April - June).    

Water Supply---
Reservoir storages across Wyoming were averaging 95 percent of average as of January 1st.  Storages at a majority of major reservoirs continue to be above water year 2008 averages.  Overall, reservoir storage is 124 percent of last water year’s reservoir storage.

The current water supply forecast calls for near normal snowmelt runoff volumes across the majority of basins across Wyoming.   Snowmelt runoff volumes are expected to be below normal the major basins across the southeast part of the state. 

Mountain Snowpack---
Snow water equivalents (SWEs) by the end of the first three months of water year 2009 were near normal across the majority of the basins across the state.  The only basins that had below normal SWEs by the beginning of January were the Lower Green River and Wind River Watersheds.

Overall Drought Picture---
Wyoming is doing fairly well with respect to water supply and mountain snowpack averages.  However, many southern rangeland locations remain rather dry during the first three months of the current water year.  In addition, the Lower Green and Upper Bear River Basins continue to be the driest basins in Wyoming---as these basins continue to be under the moderate hydrologic drought category. It is too early to get concerned about the dry conditions across southern Wyoming. As stated before---many rangeland locations (especially across areas east of the continental divide) receive 35 to 50 percent of their water year/annual precipitation during April through June.  Plus, these locations had an exceptional cool and wet spring last year.  Bottom line is that current conditions are keeping the momentum going with respect to totally breaking the long-term drought that has been plaguing Wyoming for the past 10 years.

For the rest of the Wyoming Drought Information Statement and Graphics (in PDF format)---please go to:


For additional drought graphics and information---please refer to:



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