Wednesday, February 22, 2017
Against the wind
One of the things you get in this part of the world is wind. Of course every part of the world gets wind, but here on the High Plains, on the Front Range of the Rocky Mountains, the winds are generally longer lasting, stronger, and carry higher sustained velocities. There are a lot of reasons for this, but perhaps the main one is that there aren't a lot of obstructions around for the wind to dissipate energy against.
A clue to the quality and character of regional winds is the location of massive wind farms just 20 miles to the south of the ranch. Which I can easily see on the horizon as I go about my biddness.
Yesterday I worked on fence in the wind and it was a less than completely enjoyable experience. I was prepping a calving paddock in anticipation of the winter storm we're expecting to begin tonight.
The storm is forecast to deliver up to eight inches of snow, accompanied by stiff northerly breezes and with sharply colder temperatures falling into the low twenties and teens. Perhaps into the singles overnight. What a contrast to the last two weeks, which featured 24-hour averages in the 40's and 50's!
A complicating factor is that the cows are due to begin calving a week from today, and that you can generally expect a few to calve about a week early. Also, in my experience, weather changes seem to bring on labor in cattle.
When I did the math yesterday, the answer I came up with was "get the calving paddock ready!"
About that calving paddock. It's a small fenced pasture of about 20 acres, close to the barn and corrals, and features a nice juniper/cedar windbreak on the north side. It's a good, sheltered place for the cows and calves to ride out a winter storm.
It's close to the house, too, which is important. You never know when you'll have to do this!
So, yesterday, and the necessity or working in the wind. Over the last month I've been working on some other projects, putting off work on the calving paddock. The weather was nice, after all, and the work needed minimal -- just sorting out a couple of gates and nailing up some wire that had come loose over the winter. So I put it off and put it off until I could really put it off no longer.
And that, my friends, coincided with a very windy day indeed.
Fortunately, it was quite warm. If it had been cold and blowing the work I did would have been pretty much out of the question. Yesterday, with the air at 60 degrees and the winds sustained 45 gusting 65, the wind chill was 54 degrees. The same winds on a more typical 25 degree February day would have produced a wind chill in the 2-5 degree range. Shirley that would have kilt me!
I had to put in new gate posts, which meant augering and cleaning out post holes, placing and tamping 100 pound posts, drilling and installing gate hooks, hanging gates, then stretching and reattaching wire.
Really not much of a chore; 4-5 hours work at most. But the wind made it harder and more unpleasant. It actually blew the shovel out of my hands several times. And as I worked the wind blew my hair and eyes and ears and clothes full of stinging soil particles. By the time I finished my appearance would have seen me instantly arrested for looking like a "Dear White People."
Wind is nothing more than moving air, and we tend to treat the air surrounding us as insubstantial most of the time. As a gas, air is rather insubstantial, especially when compared to solids and liquids. At sea level it only masses 1.3 kg/m^3 (1.3 kilograms per cubic meter), compared to topsoil, at 1,200 kg/m^3 (1.2 metric tonnes) and water at 1,000 kg.m^3 (one kilogram per liter).
However, when I'm standing upright I'm roughly 2 meters tall and a half-meter wide, so I'm catching a square meter, so I'm more or less (this is a SWAG) catching a cubic meter of air at whatever velocity it happens to be travelling at.
So with wind speed at 45 mph (20.11 m/s) I'm soaking up 26.14 N (Newtons, same as Joule/m), about .587 lbf (pound force). At 65 mph (29.05 m/s) it's 37.77 N or .849 lbf.
To get the total force in pounds you multiply pound force by surface area in inches. So 45 mph yields 909.85 pounds, and 65 mph totals 1,315.95 pounds.
Holy cow! Why doesn't is smash me or knock me down? Well, it doesn't smash me because air is a gas and those molecules hit and flow around me, which is different than if a solid object of the same mass hit me. It is strong enough to knock me down if I'm not careful though. And when I'm moving into the wind, I do have to overcome that force, so it can be quite a workout!
The wind did moderate toward evening, and cows grazing against the setting sun made for pretty pictures.
As did the landscape in general.
At the end of the day I was dirty and sore and tired, but the calving paddock was ready. This morning the cows were all fine, if acting a bit antsy, which is par for the course when a weather change is in the offing. Nona the Wonder Dog didn't want to go with me to check cows, which is another sign, perhaps, of a pending weather change.
Unless the forecasters are wrong, the snow will begin tonight, continue through tomorrow, and then taper off on Friday. It'll be wintry cold throughout, and through the weekend as well.
Hmmm. Must be winter yet.