Measuring weather

Through analysis of the Doppler effect, we can also figure wind speed and direction from reflections of weather radar. This is done by measuring the Doppler "shift" in the radar pulse off precipitation particles, using them as an indicator of air motion. The radar can sense whether the air is moving toward or away from the radar station. If the wind is moving perpendicular to the radar beam, it is not measured. This radial velocity is often plotted using red to indicate air moving away from radar, and green to indicate air moving toward radar.

Even on zoomed-in portions of the full field, you can approximate the location of the radar by following the pixelated lines to where they come together. When red and green are next to each other, this could show that there is rotation in the storm. In the Doppler radar image to the right, where the very strong (bright) reds and greens come together, very strong rotation in the storm is indicated and could possibly mean a funnel cloud or tornado is possible.

Next page   -> remote observations, radar

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