Upper Bear River Basin (13)
June 1999

Snow
Snow water equivalent (SWE), at snow courses in the Bear River above the Idaho State Line, is 146 percent of average (198 percent of last year). Cool weather has slowed the normal melting of snow -- consequently the comparison to average is exaggerated. SWE for the Bear River in Utah is estimated to be 119 percent of average; that is about 149 percent of last year at this time. SWE in the Wyoming portion of the Bear River drainage (Smiths and Thomas Forks) is estimated at 157 percent of average (199 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 110 percent of average for the 2 reporting stations; this is 63 percent of the previous May. The monthly percentages range from 95 to 118 percent of average. The year-to-date precipitation, for the basin, is 108 percent of average; this is 104 percent of last year's amount. Year-to-date percentages range from 106 to 111 percent of average.

Reservoir
Woodruff Narrows reservoir is currently storing 57,300 acre feet compared to 57,300 acre feet this time last year. There is no average established for Woodruff Narrows. The total capacity of the reservoir is 57,300 acre-feet.

Streamflow
The 50 percent chance stream flow yields are expected to be near average in the Bear River drainage. The Bear River near the Utah-Wyoming State Line is expected to yield about 93,000 acre feet; that is 111 percent of average for the June through September period. Thomas Fork drainage is estimated to yield 32,000 acre-feet or 107 percent of normal for the May-September period. The 50 percent chance yield for Smiths Fork near Border is about 120,000 acre-feet (108 percent of normal) for the May-September period. The Bear River near Woodruff is expected to yield about 86,000 acre-feet, about 112 percent of normal for the June-September period. 

==================================================================================================================================
                                                      UPPER BEAR RIVER BASIN
                                               Streamflow Forecasts - June 1, 1999
==================================================================================================================================
                                              |  <<====== 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        95       109    |      120       110    |       132       152            109
                                                                    |                       |
THOMAS FK nr WY-ID State Line (Disc. MAY-SEP        20        27    |       32       107    |        38        50             30
                                                                    |                       |
Bear R nr UT-WY State Line           APR-SEP       116       124    |      130       103    |       136       146            126
                                     JUN-SEP        71        83    |       93       111    |       104       122             84
                                                                    |                       |
BEAR R nr Woodruff, UT               JUN-SEP        48        68    |       86       112    |       109       153             77
                                                                    |                       |
==================================================================================================================================
                         UPPER BEAR RIVER BASIN                         |                 UPPER BEAR RIVER BASIN
             Reservoir Storage (1000 AF) - End of May                   |        Watershed Snowpack Analysis - June 1, 1999
==================================================================================================================================
                                      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    3       149       119
                                                                        |
                                                                        |   SMITHS & THOMAS FORKS       3       199       157
                                                                        |
                                                                        |   BEAR RIVER abv ID line      6       198       146
                                                                        |
==================================================================================================================================
 * 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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