Lower Green River Basin (12)
February 2002

Snow
The Blacks Fork and Henrys Fork drainage's are below average. SWE in the Hams Fork, as of February 1, is 84 percent of average (131% of last year). Blacks Fork SWE is currently 71 percent of average (90 percent of last year). The basin, as a whole, is 81 percent of average (125 percent of last year). For more information see Basin Summary of Snow Courses at beginning of this report.

Precipitation
Precipitation was below average for the month (52 percent) for the 3 reporting stations during January. Precipitation ranged from 47 to 58 percent of average for the month. The basin year-to-date precipitation is currently 77 percent of average (131 percent of last year). Year to date percentages range from 74 to 79.

Reservoir
Fontenelle Reservoir is currently storing 141,200 acre feet; this is 77 percent of average (117 percent of last year). Flaming Gorge is currently storing 2,854,100 acre feet,this is 96 percent of average (95 percent of last year). Viva Naughton is currently storing 28,300 acre feet; this is 93 percent of average.

Streamflow
Expected yields vary from 61 to 69 percent of average across the basin. The following forecast values are based on a 50 percent chance probability for the April through July forecast period. Green River near Green River is forecast to yield about 600,000-acre feet (69 percent of average). Blacks Fork near Robertson is forecast to yield 62,000-acre feet (65 percent of average). East Fork of Smiths Fork near Robertson is estimated to yield 19,000 acre-feet (61 percent of average). The estimated yield for Hams Fork near Frontier is 45,000-acre feet (69 percent of average). Viva Naughton Reservoir inflow will be about 58,000-acre feet (65 percent of average). Flaming Gorge Reservoir inflow will be about 770,000-acre feet (65 percent of average). 

==================================================================================================================================
                                                     LOWER GREEN RIVER BASIN
                                               Streamflow Forecasts - February 1, 2002
==================================================================================================================================
                                              |  <<====== Drier ======  Future Conditions  =======  Wetter =====>>  |             
                                              |                                                                     |
  Forecast Point                     Forecast |  ==================== Chance Of Exceeding * ======================  |
                                      Period  |    90%       70%    |  50% (Most Probable)  |      30%       10%    |  30-Yr Avg.
                                              | (1000AF)  (1000AF)  |   (1000AF)  (% AVG.)  |    (1000AF)  (1000AF) |    (1000AF)
====================================================================|=======================|=====================================
Green River nr Green River, WY       APR-JUL       338       494    |      600        69    |       706       862            875
                                                                    |                       |
Blacks Fork nr Robertson             APR-JUL        43        54    |       62        65    |        74        92             95
                                                                    |                       |
EF of Smiths Fork nr Robertson       APR-JUL      14.2      16.9    |     19.0        61    |        21        25             31
                                                                    |                       |
Hams Fk blw Pole Ck nr Frontier      APR-JUL        25        36    |       45        69    |        55        70             65
                                                                    |                       |
Hams Fk Inflow to Viva Naughton Res  APR-JUL        21        43    |       58        65    |        73        95             89
                                                                    |                       |
Flaming Gorge Reservoir Inflow       APR-JUL       403       622    |      770        65    |       918      1137           1190
                                                                    |                       |
==================================================================================================================================
                         LOWER GREEN RIVER BASIN                        |                 LOWER GREEN RIVER BASIN
             Reservoir Storage (1000 AF) - End of January               |        Watershed Snowpack Analysis - February 1, 2002
==================================================================================================================================
                                      Usable |  *** Usable Storage ***  |                            Number     This Year as % of
Reservoir                            Capacity|  This      Last          |   Watershed                  of       =================
                                             |  Year      Year     Avg  |                          Data Sites   Last Yr   Average
========================================================================|=========================================================
FONTENELLE                             344.8    141.2    120.4    182.2 |   HAMS FORK RIVER             4       131        84
                                                                        |
FLAMING GORGE                         3749.0   2854.1   2992.0   2966.0 |   BLACKS FORK                 2        90        71
                                                                        |
VIVA NAUGHTON RES                       42.4     28.3      ---     30.3 |   HENRYS FORK                 2        70        69
                                                                        |
                                                                        |   GREEN above Flaming Gorge  21       125        81
                                                                        |
==================================================================================================================================
 * 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the actual volume will exceed the volumes in the table.

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