Little Snake River Basin
February 1997

Snow
Snowfall has been good across the basin this year. Currently the basin is 164 percent of average for the year and 41 percent ahead of last year at this time. SWE is esentially the same as the maximum recorded for this basin. The following graph displays both lines, but the current is the same as the maximum. All of the reporting sites are above average at this time. For more information see Basin Summary of Snow Courses at beginning of this report.

Precipitation
Precipitation across the basin is also above average. The water year-to-date basin precipitation is currently standing at 139 percent of average (8 percent more than last year). January precipitation figures are also good with only 2 sites below average for the month; Baggs and Old Battle reported 98 percent of average precipitation for January. January precipitation was 8 percent above average (76 percent of last years monthly total); this is still 23 percent more than last year at this time.

Streamflow
Stream yield, based on the 50 percent probability, is forecast to be 68 percent above average near Slater and 75 percent above average near Dixon. Near Slater the Little Snake should yield about 260,000 acre feet and near Dixon it should be about 575,000 acre feet. 
==================================================================================================================================
                                                     LITTLE SNAKE RIVER BASIN
                                               Streamflow Forecasts - February 1, 1997
==================================================================================================================================
                                              |  <<====== 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)
====================================================================|=======================|=====================================
LITTLE SNAKE R nr Slater             APR-JUL       213       241    |      260       168    |       279       307            155
                                                                    |                       |
LITTLE SNAKE R nr Dixon              APR-JUL       454       526    |      575       175    |       624       696            329
                                                                    |                       |
==================================================================================================================================
                        LITTLE SNAKE RIVER BASIN                        |                LITTLE SNAKE RIVER BASIN
             Reservoir Storage (1000 AF) - End of January               |        Watershed Snowpack Analysis - February 1, 1997
==================================================================================================================================
                                      Usable |  *** Usable Storage ***  |                            Number     This Year as % of
Reservoir                            Capacity|  This      Last          |   Watershed                  of       =================
                                             |  Year      Year     Avg  |                          Data Sites   Last Yr   Average
========================================================================|=========================================================
                                                                        |   LITTLE SNAKE RIVER          7       141       164
                                                                        |
==================================================================================================================================
 * 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the actual flow 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 flow - actual flow may be affected by upstream water management.
To February 1997 Basin Outlook Report Contents Page