Idaho’s watersheds are starting out 2013 with good soil moisture and snowpack conditions, the Natural Resources Conservation Service reports.

The NRCS has changed its reference point to determine what is a normal water year. Starting this year, it will use the 30-year period beginning in 1981, making this winter look even better.

This new snowgraph drops five wet years in the 1970s from the calculation and adds eight dry years in the 2000s. This “new normal” boosts the current snowpack relative to the 30-year normal by 12 percent statewide.

Using this calculation, mountain snowpacks range from 80 percent to 160 percent of normal, Abramovich said. In the Boise Basin, snowpack is at 103 percent of normal. The old calculations would have placed the snow pack at 93 percent, the report said.

Precipitation since October ranges statewide from 100 percent to 150 percent of normal, the agency said after conducting its first snow survey of the season at the end of December and in early January.

There’s more moisture on the way. The National Weather Service issued a weather advisory through 9 a.m. Thursday for Southwest and Central Idaho, and eastern Oregon. A strong cold front was expected to move in Wednesday night and bring rain turning to 1 to 3 inches of snow overnight.

Many Idaho reservoirs are near average with the exception of some in Central and southern Idaho.

“There is some water in the bank,” Ron Abramovich, Idaho NRCS water supply specialist said. “Idaho’s reservoirs should be in good shape this year with some stored water and snow in the high country waiting to melt and fill them up.”

Elevation plays the critical role in where the snow falls and accumulates. The higher the mountains, the deeper the snowpack.

For example, Lost River Range and the Pioneer Mountains, which include Idaho’s highest peaks, have the highest snowpack percentages.

The lowest-elevation watersheds, such as the Weiser and Owyhee basins, have the least amount of snowpack.

Rocky Barker: 377-6484