This motion is removed to make the view of the wind relative to the storm.
As storms move, their own motion can mask circulations within themselves. What separates storm relative motion from base velocity is the motion of storms are "subtracted" from the overall flow of the wind. Often, these small scale circulations are areas where tornadoes form. Storm Relative Motion images are very useful images to look for small scale circulations (called mesocyclones) in thunderstorms. As distance increases from the radar, the reported value will be for increasing heights above the earth's surface. However, since the radar only measures radial velocity, the strength of the wind will always be less than what is actually occurring unless the wind is moving directly toward or away from the radar.Īlso, the surface winds are only for areas near the radar. It is useful for determining areas of strong wind from downbursts or detecting the speed of cold fronts. It is very important to know where the radar is located as that is your reference point for proper interpolation of the wind's motion.īase Velocity images provides a picture of the basic wind field from the ½° elevation scan. In all velocity images, red colors indicate wind moving away from the radar with green colors representing wind moving toward the radar. This is called radial velocity as it is the component of the target's motion that is along the direction of the radar beam. However, the only motion it can "see" is either directly toward or away from the radar. One of the best features on the 88d Doppler radar is its ability to detect motion. View a sample composite reflectivity image (scroll down). It is used to reveal the highest reflectivity in all echoes. It is composed of the greatest echo intensity (reflectivity) from any elevation angle seen from the radar. View a sample base reflectivity image.Ĭomposite Reflectivity images utilize all elevation scans during each volume scan to create the image. This image is available upon completion of the ½° elevation scan during each volume scan. There are two versions of Base Reflectivity image the short range version which extends out to 124 nm (about 143 miles) and the long range version which extends out to 248 nm (about 286 miles). Taken from the lowest (½° elevation) slice, it is the primary image used to "see what's out there". There are two types available on the web Base (or ½° elevation) reflectivity and Composite reflectivity.īase Reflectivity is the default image. These images are just as they sound as they paint a picture of the weather from the energy reflected back to the radar.
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