As we were considering going to our cabin this weekend, I noted the conflicting weather reports. I look at three different sources: Accu-weather through a widget on my computer, Yahoo! on my iPod, and Fox News in the Duluth News Tribune.
Early in the week, one had sunny weather every day through Sunday, and another had rain every day through Sunday. The high temperatures were in the mid 70s for one and the high 60s for the other. Later in the week one had rain on Friday, the day we were leaving and sunny on Saturday, the day we were returning; the other had the weather reversed. They still had the same variance in temperature.
We drove to Brimson on Friday assuming we would have some nice weather and some not so nice weather. We had great weather both days. We had a bit of fog this morning, haze in the trees, and partly cloudy or cloudy both days. Partly cloudy was often very much that; lots of sun.
Now these are vaunted free-enterprise companies giving contradictory reports, not the "government weatherman" who people often blame for incorrect reports. One brief comment on an MPR weather report gave me an understanding for the confusion.
The report mentioned that a system was moving across the state at some given slow speed. From what little I know about weather, I assume that whatever the speed, it will not be steady. So, different forecasters will make different assumptions about when a system will arrive over an area. And of course, many systems are not large enough to cover an entire area. Not quite the comic book rain following in half-drops on the fence, but one can often see a storm one way and blue sky the other. See "It all depends on your point of view".
Showing posts with label weather forecasting. Show all posts
Showing posts with label weather forecasting. Show all posts
Saturday, September 12, 2009
Friday, March 20, 2009
We stop skiing and it snows!!
On Wednesday we decided we had enough skiing for the season, cleaned out our locker at Spirit Mt., and dropped our skis off at Ski Hut for waxing and sharpening for next season.
Today we drove to our cabin to cut more wood. The forecast was for a high in the 30s and 40s and light snow. The closer we got to Brimson, the more it snowed. When we arrived there was already a half-inch of new snow ground. And it snowed and it snowed. The temperature was about 28.
I selected a tree to cut and clipped brush around it. My hands were really getting cold as I did the last clump.
My wife had a nice fire going by then and I warmed up quickly. Meanwhile the snow was falling thicker and thicker. I was antsy and wanted to get back out, but I didn't want to get soaked.
MPR gave another weather report like I started out with. This wasn't for the Twin Cities but for the Duluth area. Here in Brimson it was snowing harder than ever. I dashed off a webmail to MPR, but it went into the maw of the bureaucracy.
Along about cocktail hour I decided I should go cut my tree for the day. I just had to get one down. With two inches accumulation it had stopped snowing. I did a six-incher and cut it into rounds. Before I gathered them up I shoveled a path to the outhouse and two the woodshed. I got out the toboggan and hauled them to a cutting stump. Then my wife came out and asked if she could help! Oh, well, I don't help much with the cooking and many other things. By six o'clock I felt satisfied that I had done all I could for the day.
Tomorrow is splitting day and maybe I'll get another tree down.
Today we drove to our cabin to cut more wood. The forecast was for a high in the 30s and 40s and light snow. The closer we got to Brimson, the more it snowed. When we arrived there was already a half-inch of new snow ground. And it snowed and it snowed. The temperature was about 28.
I selected a tree to cut and clipped brush around it. My hands were really getting cold as I did the last clump.
My wife had a nice fire going by then and I warmed up quickly. Meanwhile the snow was falling thicker and thicker. I was antsy and wanted to get back out, but I didn't want to get soaked.
MPR gave another weather report like I started out with. This wasn't for the Twin Cities but for the Duluth area. Here in Brimson it was snowing harder than ever. I dashed off a webmail to MPR, but it went into the maw of the bureaucracy.
Along about cocktail hour I decided I should go cut my tree for the day. I just had to get one down. With two inches accumulation it had stopped snowing. I did a six-incher and cut it into rounds. Before I gathered them up I shoveled a path to the outhouse and two the woodshed. I got out the toboggan and hauled them to a cutting stump. Then my wife came out and asked if she could help! Oh, well, I don't help much with the cooking and many other things. By six o'clock I felt satisfied that I had done all I could for the day.
Tomorrow is splitting day and maybe I'll get another tree down.
Sunday, March 15, 2009
Premonitions revisited and other woodsman stuff
Well, well, I did make a prediction that came true. It did snow within two weeks in Duluth. It snowed on Tuesday and into Wednesday but not as much as the forecasts predicted.
And I had a premonition about something bad happening with the big tree I cut down. What was bad was some of the wood. It was soft or riddled with bug trails. We did keep a lot of the wood, but my chopping stump is surrounded by some very crumbly stuff; any drier and it would be powder.
One somewhat useless piece had a big hole in it and a squirrel nest in the hole. The piece must have been about twenty feet up. The material inside was grass interspersed with bright yellow pieces of fluff. The extra fluff was insulation purloined from under the floor of our cabin. We wonder how many squirrels are dying of silicosis.
One premonition I should have had was that I didn't prep my chain saw properly. I trimmed some protuding pieces on a couple of rounds before splitting them. As I finished I saw a cord dangling from the saw. What's this? It was the cord for the oil cap. I had not tightened it properly after adding bar oil. There was also a puddle of oil at my feet.
I added more oil and carefully secured the cap. I successfully cut down two smaller trees, both falling in the direction I wanted. I also cut them into rounds and split them without anything untoward happening but a sore back from bending over.
One advantage to cutting a tree up in the winter is that it rests on snow for almost its entire length. The saw rarely binds and one doesn't try to cut the dirt and stones underneath.
We may now have enough wood for three weeks next winter. Only ten to twelve weeks to go.
And I had a premonition about something bad happening with the big tree I cut down. What was bad was some of the wood. It was soft or riddled with bug trails. We did keep a lot of the wood, but my chopping stump is surrounded by some very crumbly stuff; any drier and it would be powder.
One somewhat useless piece had a big hole in it and a squirrel nest in the hole. The piece must have been about twenty feet up. The material inside was grass interspersed with bright yellow pieces of fluff. The extra fluff was insulation purloined from under the floor of our cabin. We wonder how many squirrels are dying of silicosis.
One premonition I should have had was that I didn't prep my chain saw properly. I trimmed some protuding pieces on a couple of rounds before splitting them. As I finished I saw a cord dangling from the saw. What's this? It was the cord for the oil cap. I had not tightened it properly after adding bar oil. There was also a puddle of oil at my feet.
I added more oil and carefully secured the cap. I successfully cut down two smaller trees, both falling in the direction I wanted. I also cut them into rounds and split them without anything untoward happening but a sore back from bending over.
One advantage to cutting a tree up in the winter is that it rests on snow for almost its entire length. The saw rarely binds and one doesn't try to cut the dirt and stones underneath.
We may now have enough wood for three weeks next winter. Only ten to twelve weeks to go.
Wednesday, March 11, 2009
Let's not knock weather forecasters
"Blizzard bears down, a storm with heavy snow and high winds is expected to hit the Northland this afternoon" Headline, Duluth News Tribune, 2009-03-10
"Snow will persist this evening, but totals far less then expected" Online headline, Duluth News Tribune, 2009-03-10, Updated 6 p.m.
Some of the commentators to this latter article are faulting the weather forecasters for their alarmism. In general, many people fault weather forecasters for lack of "accuracy" because not as much rain fell, it was sunny when clouds were predicted, and on and on.
I would rather that weather forecasters be alarmist and give us the worst case scenario. People would really be up in arms if forecasters gave the best case scenario and the worst case happened.
The best that forecasters can do is report likely events from a complex array of weather systems. The current storm did not develop as predicted because moisture that was moving towards this area dropped it as thunderstorms farther south.
The only time I fault forecasters is when they predict clear skies and we have clouds. I can't remember any predictions like this since radar was used in weather prediction.
"Snow will persist this evening, but totals far less then expected" Online headline, Duluth News Tribune, 2009-03-10, Updated 6 p.m.
Some of the commentators to this latter article are faulting the weather forecasters for their alarmism. In general, many people fault weather forecasters for lack of "accuracy" because not as much rain fell, it was sunny when clouds were predicted, and on and on.
I would rather that weather forecasters be alarmist and give us the worst case scenario. People would really be up in arms if forecasters gave the best case scenario and the worst case happened.
The best that forecasters can do is report likely events from a complex array of weather systems. The current storm did not develop as predicted because moisture that was moving towards this area dropped it as thunderstorms farther south.
The only time I fault forecasters is when they predict clear skies and we have clouds. I can't remember any predictions like this since radar was used in weather prediction.
Wednesday, September 10, 2008
Politicians and Weather Forecasters are alike
They all tell different stories.
For Duluth, MN we have the following weather reports for 1700 today:
current temperature, tomorrow's high and low
52 60 47 CNN
64 64 48 AccuWeather 64 64 48
66 62 53 Yahoo
61 Our back porch thermometer
At least they all agree there will be rain tomorrow.
For Duluth, MN we have the following weather reports for 1700 today:
current temperature, tomorrow's high and low
52 60 47 CNN
64 64 48 AccuWeather 64 64 48
66 62 53 Yahoo
61 Our back porch thermometer
At least they all agree there will be rain tomorrow.
Wednesday, April 11, 2007
Flawed science understanding
A letter writer in today's Star Tribune claims that the global warming predictions are based on the same science that can be "incapable of accurately predicting local conditions just hours into the future." The Strib titled his letter "Global warming, Flawed science".
I think his understanding of science is what is flawed. First, what is accuracy in weather forecasting? Does he want the exact temperature to the nearest degree and the exact amount of precipitation to the tenth of an inch? Even if he wants the temperature within five degrees and definite precipitation if predicted, it might not happen. Weather does not behave with such precision; there are just too many unknown quantities. We are dealing with chaos.
Consider dust devils. Walking down the street, one may see a small whirlwind of snow or dust, no more than a foot in diameter and three feet high, that comes and goes in an instant. What happens if the sun shines through a hole in the clouds on a large parking lot? Isn't there going to be a big temperature difference between the parking lot and a park or lake nearby? Weather is filled with these little anomalies that can affect local weather.
However, if one looks at weather prediction as giving the general trend for a given area, then I think most forecasters do a darn good job. Rarely do we have a forecast of a clear, sunny day and get a rainstorm. On the other hand, we may get a forecast of precipitation and get none, the weather having been blown in a different direction by some of the chaos that can't be measured.
In other words, weather forecasters and climatologists can make reasonable predictions about trends, but they cannot give precision for a very specific locale or time. For example, in global warming, Europe may get colder. Why? If melting Greenland glaciers dump enough fresh water into the Atlantic, the Gulf Stream could be disrupted by either the decreased salinity or the cooler water. If the Gulf Stream is disrupted, Europe will get less warm air.
I think his understanding of science is what is flawed. First, what is accuracy in weather forecasting? Does he want the exact temperature to the nearest degree and the exact amount of precipitation to the tenth of an inch? Even if he wants the temperature within five degrees and definite precipitation if predicted, it might not happen. Weather does not behave with such precision; there are just too many unknown quantities. We are dealing with chaos.
Consider dust devils. Walking down the street, one may see a small whirlwind of snow or dust, no more than a foot in diameter and three feet high, that comes and goes in an instant. What happens if the sun shines through a hole in the clouds on a large parking lot? Isn't there going to be a big temperature difference between the parking lot and a park or lake nearby? Weather is filled with these little anomalies that can affect local weather.
However, if one looks at weather prediction as giving the general trend for a given area, then I think most forecasters do a darn good job. Rarely do we have a forecast of a clear, sunny day and get a rainstorm. On the other hand, we may get a forecast of precipitation and get none, the weather having been blown in a different direction by some of the chaos that can't be measured.
In other words, weather forecasters and climatologists can make reasonable predictions about trends, but they cannot give precision for a very specific locale or time. For example, in global warming, Europe may get colder. Why? If melting Greenland glaciers dump enough fresh water into the Atlantic, the Gulf Stream could be disrupted by either the decreased salinity or the cooler water. If the Gulf Stream is disrupted, Europe will get less warm air.
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