You mean every yard above ground level adds 1 MPH of wind speed? Does the hill count, or just the building? (I guess I need to find out how high up the anemometer at the Baltimore Science Center is mounted.) If I'm reading the USGS topographical PDF correctly, it looks like my sidewalk is just under 140 feet above mean high tide, if that matters, and since I have a rope that'll reach the ground from the roof, I can measure the height of the house the next time I have the strength to climb up there.
Another source says to add 0.5 m/s for every 100m of elevation above "average elevation for that square of the [200m IIRC] grid". That way I get an expected 7.5 MPH on the roof, which seems awfully low for what I felt up there.
I wonder how easily I can build a cheap-but-accurate-enough anemometer. It would be interesting to mount one at ground level in front of the house, one behind the house, and one on the roof, to compare readings.[*]
Of course, if I wait long enough, another building will catch fire on a windy day at a useful distance upwind for me to watch the pattern of the smoke flowing around my house, making a 1:1 scale wind tunnel test, and that might provide useful clues as well. Unless the smoke is too thick to make out such details, as it was the last time. Hmm.
[*] I have a bunch of experiments I'd like to do Someday that involve putting sensors in various places and having a computer automatically sample them on a schedule. Comparing temperatures in different rooms to see patterns in how the house heats and cools in response to weather; comparing outdoor temperatures on the north and south sides of the house at different heights; comparing temperature plots in a car's glove compartment, trunk. footwells, and at head level while it's parked for 24 hours on a summer day; the aforementioned wind speed comparison (even better if I can also discreetly install anemometers at other locations around the neighbourhood and gather the data by radio); a webcam + object-tracking software to see what percentage of cars going through the intersection here notice that the marked lanes shift to the left, versus how many accidentally change lanes by going perfectly straight; accelerometers in various cars to compare different people's driving styles ... I've got a buttload of ideas that I'll either never get around to or never have the resources for.
I have no idea if there is an actual mathematical rule of thumb used by actual weatherbeings, but when there's a slightly breeze on the ground, I often see the treetops moving as if an a gale. (That's New England for you: if you don't like the weather, climb a tree and it will change.)
(no subject)
might be more obvious after I've slept, but ...
Another source says to add 0.5 m/s for every 100m of elevation above "average elevation for that square of the [200m IIRC] grid". That way I get an expected 7.5 MPH on the roof, which seems awfully low for what I felt up there.
I wonder how easily I can build a cheap-but-accurate-enough anemometer. It would be interesting to mount one at ground level in front of the house, one behind the house, and one on the roof, to compare readings.[*]
Of course, if I wait long enough, another building will catch fire on a windy day at a useful distance upwind for me to watch the pattern of the smoke flowing around my house, making a 1:1 scale wind tunnel test, and that might provide useful clues as well. Unless the smoke is too thick to make out such details, as it was the last time. Hmm.
[*] I have a bunch of experiments I'd like to do Someday that involve putting sensors in various places and having a computer automatically sample them on a schedule. Comparing temperatures in different rooms to see patterns in how the house heats and cools in response to weather; comparing outdoor temperatures on the north and south sides of the house at different heights; comparing temperature plots in a car's glove compartment, trunk. footwells, and at head level while it's parked for 24 hours on a summer day; the aforementioned wind speed comparison (even better if I can also discreetly install anemometers at other locations around the neighbourhood and gather the data by radio); a webcam + object-tracking software to see what percentage of cars going through the intersection here notice that the marked lanes shift to the left, versus how many accidentally change lanes by going perfectly straight; accelerometers in various cars to compare different people's driving styles ... I've got a buttload of ideas that I'll either never get around to or never have the resources for.
(no subject)