Mother Nature's snowy coat atop the Siskiyou Mountains isn't quite threadbare, but with dry weather it is starting to wear thin.
The average snow depth on Mount Ashland and the Siskiyou Summit at the end of March is 75 percent, while the snow-water content is 82 percent.
"We had another dry month," said Steve Johnson, snow ranger for the Rogue River-Siskiyou National Forest, after spending much of Thursday measuring four snow survey sites in the Siskiyou Mountains Ranger District.
In fact, the snow-water level, which reflects how much moisture is in the snow, dropped 9 percent from 91 percent of average at the end of February, he said.
"Typically, the end of March has the highest water content levels, although over the past two springs we have actually seen an increase in the snowpack in April," said Johnson, who will take the final snow survey of the season at the end of next month.
The winter snowpack is an indicator of the coming water year, a frozen bank of water that provides for summer stream flows and reservoir storage.
The U.S. Forest Service works with the U.S. Natural Resource Conservation Service in measuring the snow survey sites throughout Oregon.
In addition to taking physical measurements near the end of each month, the agencies rely on remote SNOTEL, or snow telemetry, measuring devices to determine the snow-water content by measuring the weight of the snow.
The snow-water content of the mountains ringing the Rogue and Umpqua basins is currently at 78 percent of average, according to the SNOTEL sites. It was 92 percent at the end of March 2012.
During his excursion into the mountains, Johnson, who has been keeping track of the local snow depth for more than two decades, encountered a variety of weather.
"Sunshine, rain, snow, mist, blue sky, clouds, wind and no wind" — a typical Southern Oregon spring day, he said.
At the Siskiyou Summit, elevation 4,600 feet above sea level, Johnson measured 9 inches of snow for 90 percent of average. However, the water content was 4.2 inches, reflecting 168 percent of average.
Established in 1935, the Siskiyou Summit site a few miles west of Interstate 5 averages about 10 inches of snow this time of year.
Farther up Mount Ashland at 6,000 feet, the snow ranger found 41 inches of snow for 63 percent of average at the Ski Bowl Pass site. The snow-water content of 16 inches is 68 percent of average.
The Mount Ashland Switchback site at 6,500 feet had 62 inches of snow for 76 percent of average. The snow water measured 26.1 inches for 81 percent of average.
The Caliban II, also located at 6,500 feet, had 66 inches of snow for 85 percent of average. The snow-water measurement was 26.4 inches, making it 86 percent of average.
Down on the valley floor, the precipitation since Sept. 1 has been 14.44 inches, slightly above the 14.14-inch average, according to the U.S. National Weather Service station at the Medford airport.
However, the valley, like the surrounding mountains, received the lion's share of its moisture late in the fall and early winter.
Only .24 inches of rain has been recorded at the station since the beginning of March, well below the 1.5-inch average.
Reach Mail Tribune reporter Paul Fattig at 541-776-4496 or email him at email@example.com.