The reason is that even though we can't quite pry Old Man Winter's bony fingers off us, other things are
proceeding.
Longer days
We are a month past the vernal equinox now and daylight hours significantly outnumber the dark ones. Sunlight, the giver of all life on Earth, will warm up every dark surface, regardless of the air temperature. Rocks, logs and weeds stuck in the ice will absorb the sun rays and holes will appear through the more than three-feet of existing ice. Marshy ends of bays will melt entirely. The lake ice will break free of the shoreline, rising up so that it is higher than the water level when it froze.Dirt and debris on the lake will melt holes down into the ice, some will go all the way through. Water will pool on the surface, turning it darker in colour and this too will warm up from the sun.
But longer days will have little effect if the sky is cloudy. So we need lots of sunny days, even if they are cold, for the sunlight factor to overcome the colder-than-normal temperatures.
Wind
Snow and ice melt far faster on warm windy days than on calm ones. The wind both blows the warm air in and carries the cold air away. In the West they have a name for this -- chinook. It is a First Nation's term and means snow-eating wind.
The good news is that the wind that blew relentlessly all winter, that created frightening wind chills, is still with us. This spring may not be as warm as normal but it is also far windier. The meager above-freezing temperatures are being multiplied by the wind, at least as far as melting snow and ice go.
There is still a couple of feet of snow on the ground but it is rotten. It would only take a couple of really warm days to finish it.
The wind also plays another role -- it actually creates a current under the ice, at least in some places. Here's how. When the wind blows it pushes down on the ice where the ice expanse is widest -- the center. This displaces the water beneath the ice away from the big sections, sending it rushing into the bays. This is most evident in long, narrow bays. But wind is seldom steady; it gusts and lays and then gusts again. So the water moves into these bays and then moves out again, back and forth. That's why there is a sandbar at the entrance to virtually every narrow bay. Think of Green Bay in Pipestone, Golden Arm, Marten Bay. The sand came from the action of the wind on the water, underneath the ice. Sediment in the water falls out every time the current reverses.
Every bush-wise snowmobiler and lake traveler knows that the ice is no good at the entrances of long bays. The back-and-forth current here makes the ice thinner and the sandbar makes the water shallower. In the spring, the sunlight will warm the water up here quickly so that these are the second places to open after the mouths of creeks that have continuous current.
Although we are still a long way from it happening, eventually it will be the wind that dashes the ice pans to bits. This will occur when the ice has melted a few feet from the shore and has room to move.
No more snow
If the lake ice is going to disappear before the season opener, we cannot have any more snowfalls like we had a few days ago. About three inches fell in Red Lake, much more in other places. A snowfall like this sets back the melting process by several days.
Rain
A warm rain really rots lake ice quickly. It will create pools on the surface that will find cracks that go all the way through. The water will pour through these, widening them and weakening the entire sheet.
Rain also sends torrents of water from land onto the lake, bringing with it dirt that absorbs sunlight.
Temperature
Obviously, nothing melts snow and lake ice like warm temperatures. Even if they aren't normal, they must be above freezing, especially at night. If it freezes at night, it takes half of the next day to melt the new ice. So we still need it to warm up. We should be experiencing highs of 10 C to 15 C (about 40 F to 50 F) and lows of 0 C to 5 C (32 F to 40 F). Instead we are getting highs of 5 C to 10 C and lows of -5 to -10 C. That's not good. The weather forecasts continually predict it to warm up within a week. So far, it hasn't happened.
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1 comment:
Thank you for the great read. I guide at Sabourin lake lodge and watch the weather religiously. This is always a tough time of year, waiting on mother nature.
Thanks
Jim
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