Upper Bear River Basin (13)
June 2000

Snow
Snow water equivalent (SWE), at snow courses in the Bear River above the Idaho State line, is 5 percent of average (4 percent of last year). SWE for the Bear River in Utah is estimated to be 1 percent of average; that is about 1 percent of last year at this time. SWE in the Wyoming portion of the Bear River drainage (Smiths and Thomas Forks) is estimated at 9 percent of average (5 percent of last year at this time.). See the Basin Summary of Snow Course Data at the beginning of this report for more detailed information.

Precipitation
Precipitation for the month of May was 112 percent of average for the 2 reporting stations; this is 102 percent of the previous May. The monthly percentages range from 102 to 123 percent of average. The year-to-date precipitation, for the basin, is 81 percent of average; this is 75 percent of last year's amount.

Reservoir
Woodruff Narrows did not report this month.

Streamflow
The following 50 percent chance stream flow yields are for the May through September period. Smiths Fork near Border is estimated to yield 63,000 acre-feet (58 percent of normal), and Thomas Fork drainage near the Idaho- Wyoming state line is estimated to yield 14,000 acre-feet or 47 percent of normal. The following 50 percent chance stream flow yields are for the June through September period. Bear River near the Utah-Wyoming State Line is expected to yield about 50,000 acre feet; that is 60 percent of average, while Bear River near Woodruff is expected to yield about 43,000 acre-feet, about 56 percent of normal. 

==================================================================================================================================
                                                      UPPER BEAR RIVER BASIN
                                               Streamflow Forecasts - June 1, 2000
==================================================================================================================================
                                              |  <<====== 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)
====================================================================|=======================|=====================================
SMITHS FK nr Border, WY              MAY-SEP        50        57    |       63        58    |        69        80            109
                                                                    |                       |
THOMAS FK nr WY-ID State Line (Disc. MAY-SEP       8.9      11.7    |     14.0        47    |      16.8        22             30
                                                                    |                       |
Bear R nr UT-WY State Line           APR-SEP        68        72    |       76        60    |        80        86            126
                                     JUN-SEP        38        45    |       50        60    |        56        66             84
                                                                    |                       |
BEAR R nr Woodruff, UT               APR-SEP        62        77    |       90        58    |       105       131            154
                                     JUN-SEP        24        34    |       43        56    |        54        76             77
                                                                    |                       |
==================================================================================================================================
                         UPPER BEAR RIVER BASIN                         |                 UPPER BEAR RIVER BASIN
             Reservoir Storage (1000 AF) - End of May                   |        Watershed Snowpack Analysis - June 1, 2000
==================================================================================================================================
                                      Usable |  *** Usable Storage ***  |                            Number     This Year as % of
Reservoir                            Capacity|  This      Last          |   Watershed                  of       =================
                                             |  Year      Year     Avg  |                          Data Sites   Last Yr   Average
========================================================================|=========================================================
WOODRUFF NARROWS                                NO REPORT               |   UPPER BEAR RIVER in Utah    5         1         1
                                                                        |
                                                                        |   SMITHS & THOMAS FORKS       3         5         9
                                                                        |
                                                                        |   BEAR RIVER abv ID line      6         4         5
                                                                        |
==================================================================================================================================
 * 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the actual volume will exceed the volumes in the table.

The average is computed for the 1961-1990 base period.

(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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