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Wyoming Basin Outlook Report for
UPPER NORTH PLATTE RIVER BASIN as of March 1, 2012

Snow The SNOTELS above Seminoe Reservoir are showing about 81% of average (SWE) for this time of the year. SWE in the drainage area above Northgate is 78% of average at this time. SWE in the Encampment River drainage is about 82% of average. Brush Creek SWE for the year is about 81% of average. Medicine Bow and Rock Creek drainages SWE are about 84% of average. For more information see Basin Summary of Snow Course Data at the beginning of this report. Precipitation Eight reporting stations show last month s precipitation at 135% of average or 100% of last year's amount. Precipitation varied from 88-191% of average last month. Total water-year-to-date precipitation is about 96% of average for the basin, which is about 66% of last year's amount. Year to date percentage ranges from 83- 142% of average. Reservoirs Seminoe Reservoir is estimated to be storing 845,200 ac-ft or 83% of capacity. Seminoe Reservoir is also storing about 160% of average for this time of the year and 107% of 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 following yields are the 50% exceedance forecasts for the April through September period and are expected to be below average for the Upper North Platte River Basin. Yield for the North Platte River near Northgate will be around 175,000 ac-ft (65% of average). The Encampment River near Encampment is 123,000 ac-ft (75% of average). Rock Creek near Arlington is 48,000 ac-ft (84% of average). The Sweetwater River near Alcova forecast is for 64,000 ac-ft (80% of average). Seminoe Reservoir inflow should be around 580,000 ac-ft (67% of average). See the following table for more detailed information on projected runoff.

Streamflow Forecasts

UPPER NORTH PLATTE RIVER BASIN
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)

North Platte R nr Northgate
APR-JUL 47       113       158       65       205       270       245      
APR-SEP 50       125       175       65       225       300       270      
Encampment R nr Encampment
APR-JUL 73       98       115       74       132       157       156      
APR-SEP 78       105       123       75       141       168       165      
Rock Ck nr Arlington
APR-JUL 30       40       46       87       52       62       53      
APR-SEP 31       41       48       84       55       65       57      
Sweetwater R nr Alcova
APR-JUL 30       47       59       80       71       88       74      
APR-SEP 32       51       64       80       77       96       80      
Seminoe Reservoir Inflow (2)
APR-JUL 117       370       540       68       710       965       800      
APR-SEP 117       395       580       67       765       1040       860      

    * 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

UPPER NORTH PLATTE RIVER BASIN
Reservoir Storage (1000AF) End of February

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

SEMINOE 1016.7      845.2         793.4          527.4        



Watershed Snowpack Analysis

UPPER NORTH PLATTE RIVER BASIN
Watershed Snowpack Analysis - March 1, 2012

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

N PLATTE above Northgate 7               59               78              
ENCAMPMENT RIVER 4               65               82              
BRUSH CREEK 5               55               81              
MEDICINE BOW & ROCK CREEKS 3               64               84              
N PLATTE above Seminoe 19               61               81              

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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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