1. Ancient Wind Measurement
Wind vanes were perhaps the most ancient meteorological instruments.
Mesopotamian and Sumerian documents, dating back nearly 4,000 years, describe primitive wind vanes, and streamers were used for wind direction measurement in China during the second century B.C.E.

2. Wind Measurement
The famous Tower of the Winds in Athens, dating back at least to 50 B.C.E., was topped by a wind vane in the form of a Triton
Wind vanes and wind banners were common during the Middle Ages, and were found on many churches, ships, and towers.

4. Wind Vane

5. Development of anemometers

6. Modern Three-Cup Anemometer

7. Combo

9. Sometimes anemometers and wind vanes have had icing issues.

10. New Sonic Anemometer
Old
The solution….

11. Sonic Anemometer

12. Proper Exposure of Wind Instruments
Open area
Sensors at 10 m (roughly 30 ft) above the ground
Not right above pitched roof.

13. Sustained Winds and Wind Gusts
Sustained: usually average of 1-2 minutes
Gusts: typically strongest 3-5 second average wind reported.
Typically about a ratio for (gust/sustained), but can be much more in some occasions.

16. You Can Often See Gusts Over Water—called “cat’s paws”

18. Why Gusts?

19. Winds are often far stronger over water than land
Water is much smoother aerodynamically than land
Trees, building, hills, etc. all slow down winds near the surface.
Wind over water can be % stronger (or more) than over land.

23. Estimating Wind Subjectively
Wind direction: flags, low clouds, trees and branches, throw grass in air
Wind speed: Beaufort Scale

24. Sir Francis
Beaufort, 1805

25. Wind Terminology Gale: 34-47 knots Storm: 48-64 knots
Hurricane: 65+ knots

26. Strongest Near Surface Winds
Anemometer: 231 mph, Mt. Washington, NH 1934
Radar: 318 mph, OK City Tornado, 3 May 1999

27. Columbus Day 1962: At Cape Blanco there were 150 mph with gusts to 179
Columbus Day 1962: At Cape Blanco there were 150 mph with gusts to 179! Strongest winds on bluffs and windward slopes of coastal orography

28. Why Wind? Created by differences in pressure.
Air accelerates from high to low pressure