Not sure if this will help, but the Average Annual Rainfall for Orovada Nevada is 10.48 inches and for King's Valley Nevada it is 8.5 inches.  Bracketing on either side of Thacker Pass the Average Annual Rainfall in Thacker Pass should be somewhere between those two values.

Average Annual Snowfall for Oravada Nevada is 18 inches and for King's River Valley it is 19.1 inches.

"When converting snowfall amounts to rain or water equivalents, the temperature plays a role.

A snow-to-liquid ratio is used to convert liquid precipitation to snow. The snow-to-liquid ratio depends on temperature. The colder the temperature, the higher the snow-to-liquid ratio.

For example, 10 inches of snow at 34 to 28 degrees would equal 1 inch of water. At 19 to 15 degrees, 20 inches of snow would equal 1 inch of water."

These figures for annual precipitation reflect decades of collection of data for both Oravada and for King's River Valley.  I don't believe that the data has been collected for Thacker Pass.  Just some reference data that might be of value when the December Hearing on the Water Rights issue becomes a reality next month.

Okiedo