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Wyoming Basin Outlook Report for
SNAKE RIVER BASIN as of March 1, 2012

Snow The Snake River Basin snow water equivalent (SWE) is 95% of average. SWE in the Snake River Basin above Jackson Lake is 101% of average. Pacific Creek Basin SWE is 117% of average. Gros Ventre River Basin SWE is 88% of average. SWE in the Hoback River drainage is 87% of average. SWE in the Greys River drainage is 90% of average. In the Salt River area SWE is 89% of average. SWE in the Snake River Basin above Palisades is 95% of average. See the Basin Summary of Snow Course Data at the beginning of this report for a detailed listing of snow course information. Precipitation Precipitation across the basin was about average last month. Monthly precipitation for the basin was 98% of average (129% of last year). Last month's percentages range from 72-127% of average for the 16 reporting stations. Water-year-to-date precipitation is 96% of average for the Snake River Basin (89% of last year). Year-to- date percentages range from 68-116% of average. Reservoir Current reservoir storage is 122% of average for the 3 storage reservoirs in the basin. Grassy Lake storage is about 103% of average (12,300 ac-ft compared to 13,200 last year). Jackson Lake storage is 130% of average (640,000 ac-ft compared to 656,600 ac-ft last year). Palisades Reservoir storage is about 118% of average (1,223,500 ac-ft compared to 875,700 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 April through September are below average for the basin. The Snake near Moran is 905,000 ac-ft (100% of average). Snake River above reservoir near Alpine is 2,560,000 ac-ft (94% of average). The Snake near Irwin is 3,570,000 ac-ft (92% of average). The Snake near Heise is 3,830,000 ac-ft (92% of average). Pacific Creek near Moran is 200,000 ac-ft (112% of average). Buffalo Fork above Lava near Moran is 360,000 ac-ft (105% of average). Gros Ventre River at Kelly is 260,000 ac-ft (107% of average). Greys River above Palisades Reservoir is 355,000 ac-ft (90% of average). Salt River near Etna is 365,000 ac-ft (87% of average). See the following page for detailed runoff volumes.

Snow Currently, snow water equivalent (SWE) in the Little Snake River drainage is 83% of average. For more information see Basin Summary of Snow Course Data at the beginning of this report. Precipitation Precipitation across the basin was 133% of average (121% of last year) for the 5 reporting stations. Last month s precipitation ranged from 106-166% of average. The Little Snake River basin water-year-to-date precipitation is currently 88% of average (67% of last year). Year-to-date percentages range from 71-101% of average. Reservoir High Savery Dam - 11,835 ac-ft Streamflow The 50% exceedance forecast for the April through July time frame on the Little Snake River drainage is expected to be below average this year. The Little Snake River near Slater should yield around 130,000 ac-ft (82% of average). The Little Snake River at Savery is estimated to yield around 270,000 ac-ft (82% of average). See the following table for more detailed information on projected runoff.

Streamflow Forecasts

SNAKE 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)

Snake R nr Moran (1,2)
APR-JUL 640       765       820       101       875       1000       815      
APR-SEP 695       840       905       100       970       1110       905      
Snake R nr Alpine (1,2)
APR-JUL 1730       2070       2230       94       2390       2730       2370      
APR-SEP 1970       2380       2560       94       2740       3150       2730      
Snake R nr Irwin (1,2)
APR-JUL 2430       2870       3070       92       3270       3710       3330      
APR-SEP 2860       3350       3570       92       3790       4280       3870      
Snake R nr Heise (2)
APR-JUL 2730       3060       3280       92       3500       3830       3560      
APR-SEP 3210       3580       3830       92       4080       4450       4160      
Pacific Ck At Moran
APR-JUL 149       176       194       114       210       240       171      
APR-SEP 153       181       200       112       220       245       178      
Buffalo Fork ab Lava nr Moran
APR-JUL 260       290       315       105       340       370       301      
APR-SEP 295       335       360       105       385       425       344      
Gros Ventre R at Kelly
APR-JUL 157       191       215       108       240       275       200      
APR-SEP 192       230       260       107       290       330       244      
Greys R Nr Alpine
APR-JUL 240       280       305       90       330       370       340      
APR-SEP 280       325       355       90       385       430       395      
Salt R Nr Etna
APR-JUL 179       250       295       87       340       410       340      
APR-SEP 225       310       365       87       420       505       420      
Little Snake R nr Slater (2)
APR-JUL 89       113       130       82       149       178       159      
Little Snake R nr Savery (2)
APR-JUL 170       225       270       82       320       390       330      

    * 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

SNAKE RIVER BASIN
Reservoir Storage (1000AF) End of February

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

Grassy Lake 15.2      12.3         13.2          12.0        
Jackson Lake 847.0      640.0         656.6          494.0        
Palisades 1400.0      1223.5         875.7          1033.1        



Watershed Snowpack Analysis

SNAKE RIVER BASIN
Watershed Snowpack Analysis - March 1, 2012

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

SNAKE above Jackson Lake 9               99               101              
PACIFIC CREEK 3               111               117              
GROS VENTRE RIVER 4               77               88              
HOBACK RIVER 5               82               87              
GREYS RIVER 4               80               90              
SALT RIVER 5               82               89              
SNAKE above Palisades 28               89               95              
LITTLE SNAKE RIVER 8               69               83              

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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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