Southeast falls below-average in snowpack survey

 

Submitted Illustration

This chart shows the five-year trend of snowpack for the two sites on Mitkof Island as measured each January. The old water reservoir site is the lower site, measuring 550-feet. The Raven's Ridge is the upper site, measuring 1650-feet elevation.

Findings from the Alaska Snow Survey Report released February 2015 show that snowpack across the state of Alaska is below normal, and snowpack in Southeast is less than half the normal rate.

The USDA's Natural Resources Conservation Service (NRCS) releases the report quarterly. Locally, data is collected by U.S. Forest Service hydrologist Heath Whitacre who surveys two sites on Mitkof Island: a 1650-foot high site on Raven's Ridge and a 550-foot high site near the old water reservoir. Whitacre's monthly tally is sent to the NRCS where it is combined with data from sites around Alaska to assess seasonal snowpack trends for the state.

Below-normal levels of snowpack this year are the norm across the state, save for two areas-the Arctic and a swath of mainland Alaska near Delta Junction-which have normal levels of recorded snowpack.

In Southeast snowpack was described in the report as "meager, with most snow courses reading less than a quarter normal." For the Petersburg-Wrangell area in particular there has been "very little snow" this season, which is attributable to higher-than-normal temperatures.

"Temperature, rather than amounts of precipitation, was the controlling factor for snowpack so far this winter," according to the report. "Much precipitation came as rain across the state instead of snow and what little snow accumulated early in the season has diminished."

In fact, warmer days in January combined with wet conditions to produce the rainiest January on record in Petersburg.

Snowpack is one of several factors affecting water levels in streams and thus salmon runs. However, summer precipitation and temperature also have a bearing on those levels and potential impacts.

Though the recent five-year trend of snowpack in Southeast has been mostly downward, Daniel Fisher, an NRCS hydrologist based out of Palmer, said decades of data have revealed a lot of variability year to year.

"There's just a lot of seasonal variability," he said. "Last year was fairly low, but that was followed by two years that were record highs."

Fisher said data from the survey gets used for a host of purposes including flood forecasting, wildlife management and recreation. However, the program was created for a different purpose.

"The snow survey program is actually mandated by congress to collect snowpack data in the west and Alaska mainly for water supply forecasting,"

he said.

 

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