Wet month keeps snowpack below 30-year average

Mar 5, 2013 By Eric Blom, Staff Writer

City weather in February

High: 50 (Feb. 4)

Low: -2 (Feb. 12)


temperature: 23.9

30-year average: 24.3

Snowfall: 8.8 inches

Moisture: .54 inch

Riverton in February was slightly colder than normal and saw double the normal amount of precipitation, but snowpack in local basins still remains a bit below average. The National Weather Service's Riverton station released a monthly weather report March 2.

The NWS said the average temperature in Riverton was 23.9 degrees in February, nearly right on the 30-year average of 24.3 degrees.

The month did not set any temperature records, but the coldest reading was 2 degrees below zero Feb. 12, and the highest was 50 degrees Feb. 4.

Riverton saw 8.8 inches of snowfall in February, which translates into .54 inch of precipitation. That amount of moisture is 200 percent of average.

The NWS reports February 2013 was the 10th wettest on record for Riverton.

Since Jan. 1, Riverton has seen .65 inch of precipitation, which is 120 percent of normal and almost 140 percent of last year's moisture in the same period.

"Pretty much Lander and Riverton were the only areas (in the county) that got decent months of precipitation," National Weather Service meteorologist Trevor LaVoie said.

He explained the direction of the snow storms meant the northwest part of Fremont County saw less snow.

He thinks the stream flows, an indicator of how wet or dry the area is, will improve slightly.

"The stream flow was still below normal (in early February)," LaVoie said. "(Recent snow) will probably up the numbers."

The NWS's Riverton station also released a report Feb. 28 saying drought conditions improved in western Wyoming. It said the severity decreased in Lincoln and Teton counties, but maps show conditions in Fremont County barely improved.


Most snow monitoring sites in the mountains surrounding the Wind River and Sweetwater River Basins report several more inches of moisture accumulated in February.

The devices, called snotels, measure snow depth and inches of snow water equivalent, more or less the amount of water the snowpack would produce if melted.

The buildup of precipitation, however, has not kept pace with the average. The snow water equivalent in the Wind River Basin as of March 4 was 85 percent of the 30-year average for the date.

That is down from Jan. 25, when it was at 88 percent of normal for that time.

Water conditions in the Sweetwater River Basin have improved slightly.

On March 4 snow water equivalent levels measured 80 percent of average for the date. The same measurement stood at 77 percent of normal on Jan. 25 for that time.

Last year at this time, snowpack in the Wind River Basin was 115 percent of average, and in the Sweetwater River Basin it was 105 percent of normal.

Basins along the Montana border, however, improved, and snow in all of them are at 90 percent or better.

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