Entries show station weight (percent), station latitude (degrees N), station longitude (degrees E), and station name for each of the stations in the index.
1 9.51 38.999 -119.157 YERINGTON 2 12.82 39.484 -119.771 RENO AP 3 16.99 38.955 -119.776 MINDEN 4 23.66 39.313 -119.648 VIRGINIA CITY 5 37.02 39.075 -119.941 GLENBROOK
The station weight is based on the average annual precipitation at that station, so that a wet station contributes more to the final index that does a dry station. The final weight is normalized so that the sum of all the weights adds up to 100%.
Stations are selected based on two criteria. 1) They must have a relatively long (50 year or more) record with few interruptions. 2) They must be updated nearly every day by the California Nevada River Forecast Center.