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Wyoming Basin Outlook Report for
SHOSHONE & CLARKS FORK RIVER BASINS as of March 1, 2012

Snow Snowpack in these basins is near average for this time of year. Snow Water Equivalent (SWE) is 100% of average in the Shoshone River Basin. The Clarks Fork River Basin SWE is 100% of average. See the Basin Summary of Snow Course Data at the front of this report for details. Precipitation Precipitation for last month was 127% of average (146% of last year). Monthly percentages range from 100-143% of average. The basin year-to-date precipitation is now 118% of average (103% of last year). Year-to-date percentages range from 100-147% of average for the 8 reporting stations. Reservoir Current storage in Buffalo Bill Reservoir is about 109% of average (101% of last year's storage) the reservoir is at about 68% of capacity. Currently, about 442,000 ac-ft are stored in the reservoir compared to 438,100 ac-ft last year. Detailed reservoir data is shown on the following page and on the reservoir storage summary at the beginning of this report. Streamflow The 50% exceedance forecasts for the April through September period are expected to be above average for the basin. The North Fork Shoshone River at Wapiti is 550,000 ac-ft (106% of average). The South Fork of the Shoshone River near Valley is 275,000 ac-ft (104% of average), and the South Fork above Buffalo Bill Reservoir runoff is 245,000 ac-ft (109% of average). The Buffalo Bill Reservoir inflow is expected to yield around 840,000 ac-ft (104% of average). The yield for the Clarks Fork of the Yellowstone near Belfry, Montana is expected to be around 610,000 ac-ft (103% of average). See the following page for detailed runoff volumes.

Streamflow Forecasts

SHOSHONE & CLARKS FORK RIVER BASINS
Streamflow Forecasts - March 1, 2012

 <==== Drier === Future Conditions === Wetter ====> 
Forecast Pt============ Chance of Exceeding * =========== 
   Forecast90%70%50% (Most Prob)30%10%30 Yr Avg
   Period(1000AF)(1000AF)(1000AF)(% AVG.)(1000AF)(1000AF)(1000AF)

NF Shoshone R at Wapiti
APR-JUL 390       450       490       107       530       590       460      
APR-SEP 440       505       550       106       595       660       520      
SF Shoshone R nr Valley
APR-JUL 194       220       240       107       260       285       225      
APR-SEP 225       255       275       104       295       325       265      
SF Shoshone R ab Buffalo Bill Res
APR-JUL 161       205       235       109       265       310       215      
APR-SEP 167       215       245       109       275       325       225      
Buffalo Bill Reservoir Inflow (2)
APR-JUL 600       695       760       106       825       920       720      
APR-SEP 665       770       840       104       910       1020       805      
Clarks Fk Yellowstone R nr Belfry
APR-JUL 460       520       560       104       600       660       540      
APR-SEP 500       565       610       103       655       720       595      

    * 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the
       actual flow will exceed the volumes in the table.

    (1) - The values listed under the 10% and 90% Change of Exceeding are
            actually 5% and 95% exceedance levels.
    (2) - The value is natural flow - actual flow may be affected by upstream
            water management.



Reservoir Storage

SHOSHONE & CLARKS FORK RIVER BASINS
Reservoir Storage (1000AF) End of February

 Usable************* Usable Storage *************
Reservoir Capacity This Year Last Year Average

BUFFALO BILL 646.6      442.0         438.1          405.8        



Watershed Snowpack Analysis

SHOSHONE & CLARKS FORK RIVER BASINS
Watershed Snowpack Analysis - March 1, 2012

 Number ofThis Year as Percent of
Watershed Data Sites Last Year Normal

SHOSHONE RIVER 6               102               100              
CLARKS FORK in WY 7               90               100              

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E-mail Questions or Comments

or Write:
D. Lee Hackleman, Water Supply Specialist
Natural Resources Conservation Service
100 East B Street
Casper, WY 82601
(307) 261-6481

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