Warmer temperatures cause flood potential

It looks as if we finally made it through a week without any heavy snows or strong winds. Milder temperatures have slowly begun to eat through the mountains of snow piled up across the area. Can spring be too far down the road?

As temperatures start to warm, the focus moves from winter storms to flood potential. Above normal snowpack across the mountains can definitely be viewed as a plus, when we think in terms of water resources during the hot and dry summer. The key is keeping the water on the mountains in its frozen form as long as possible.

If exceptionally mild air arrives too early in the season, rapid snowmelt can lead to flooding, especially if the mild temperatures are accompanied by heavy rains. Ground conditions in late winter leave the area more prone to flooding, as the frozen ground cannot absorb large amounts of water from snowmelt or precipitation. Rapid mountain snowmelt too early in the season also becomes a wasted resource, as there remains little chance to “restock” the snowpack before the dry season begins.

As nice as 60 degrees may sound right now, it is definitely in everyone’s best interest for Mother Nature to take a slow and steady approach to warming up temperatures.

In general, across the Panhandle, snowpack is running about 120 percent of normal. This is based on “snowpack telemetry” reports from 18 mountain locations. You might assume that the percentages would be much higher, based on the amount of shoveling you’ve had to do this season. In reality, the mountain locations have received above normal snow amounts, but not to the extent at which the lower elevations have seen.

Keeping track of mountain snowfall might seem like a daunting task, when you consider that observations are needed daily throughout the cold season. Observations are taken at remote locations, nearly half a dozen of which are at elevations above 6,000 feet. For the last 28 years, SNOTEL, an automated system, has been operated and maintained by the Natural Resources Conservation Service. The system collects data on snowfall, which is useful for producing water supply forecasts, as well as supporting climate studies, air and water quality investigations, and water resource management.

What makes SNOTEL most interesting, however, is the technology involved in transmitting the data from the remote locations to a central computer in Portland. In what is called “meteor burst communications,” radio signals are sent 50 to 75 miles above the Earth to an ever-present band of ionized meteorites. The signal is reflected off those meteorites back to Earth and received at Portland’s National Water and Climate Center. There are 730 SNOTEL sites in 11 states including Alaska, and the Idaho Panhandle is home to 18.

We have heard plenty about snow this season, but I have also recently received a few e-mails asking about how temperatures have stacked up this winter. Though we did experience a few days in the deep freeze, where nighttime lows briefly dipped below zero, we have not otherwise seen much in the way of temperature extremes. December ended with average temperatures slightly above normal; January was slightly below normal; and so far February is slightly above normal.

Highs currently average in the lower 40s, with nighttime temperatures averaging in the upper 20s. The record high for the month is 62 degrees, set on Feb. 24, 1981. The record low for the month is a bone-chilling 29 degrees below zero, on Feb. 9, 1933.