How is snowfall measured?
It’s too soon to say flooding will be a problem for Saskatchewan farmers this year, but the first provincial spring forecast does predict above normal runoff.
The Water Security Agency last week confirmed what most people see when they look outside: this winter’s snowfall has been significant.
Most of Saskatchewan has seen more snow than usual, with the Moose Jaw, Regina and Yorkton areas receiving well above normal amounts.
The snow is also unusually wet.
WSA spokesperson Patrick Boyle said snow pack water equivalent is the amount of water that would be created if all the snow on the ground melted.
“We measure that remotely by satellites but we also do traditional on-the-ground sampling to verify the readings,” he said.
The samples found that the estimated water equivalent across the entire agricultural zone is 200 percent of normal.
Boyle said forecasters can’t yet say if this will contribute to flooding. That will depend on how much more snow falls, the rate of melt closer to spring and rainfall during the runoff period.
If precipitation during the next couple of months is normal, above average runoff is still expected.
Widespread and serious flooding in 2010 and 2011 has people on guard.
About 1,400 individuals, communities, rural municipalities and First Nations have since obtained more than $25 million in flood mitigation funding.
“We’re probably in a better spot with investments in mitigation works,” Boyle said about the province’s ability to handle flooding again.
As well, dry conditions last fall should mean the soil is able to absorb at least some of the melt.
The agency will produce another more detailed runoff forecast in early March.
Meanwhile, as of Feb. 1, the snow pack in the headwaters of the North Saskatchewan River is slightly below normal and in the headwaters of the Oldman River basin is slightly above normal.
Environment Canada is forecasting near normal precipitation in February, March and April for most of the Prairies except Manitoba, where above normal precipitation is expected for much of the province outside the far south.
- Environment Canada staff use instruments such as the nipher snow gauge or the Geonor bucket to capture snow, measure its water content and report the findings to a satellite network. Water equivalent measurements are reported (in millimetres) instead of snow because equal amounts of snow can hold differing amounts of water, depending on relative humidity and other factors.
- Automatic reporting stations are sometimes also equipped with a snow depth sensor. The sensor aims a high-frequency pulse at the ground, which bounces back when it strikes the surface of the snow. A computer calculates the snow depth using the time it takes for the pulse to return to the sensor. Using this data, meteorologists can determine the change in snowfall from day to day and also how much snow has accumulated at each station.
- Brooks, Alta. 48.3
- Coronation, Alta. 49.1
- High Level, Alta. 68.6
- Medicine Hat, Alta. 44.2
- Peace River, Alta. 63.3
- Vegreville, Alta. 41.1
- Assiniboia, Sask. 56.7
- Estevan, Sask. 52.1
- Maple Creek, Sask. 61.3
- North Battleford, Sask. 51.4
- Shaunavon, Sask. 59.7
- Yorkton, Sask. 54.5
- Brandon, Man. 54.9
- Dauphin, Man. 59.7
- Gimli, Man. 72.3
- Morden, Man. 67.4
- Portage la Prairie, Man. 76.6
- Russell, Man. 69.5