Almost everyone has seen radar images of precipitation on television or online in the past and knows at least a little about how to interpret them. While many television stations have their own low-power radars, the majority of weather radar images come from the National Weather Service. But their radar images come in two ways which are useful for different purposes. According to this article in Forbes.com, composite radar images combine radar pictures at numerous sites and stitches them together into a large-scale picture of rain across a region such as the Southeast US. This gives you a quick glance at weather patterns across a wide area and can provide you with plenty of warning of an approaching weather system. But because the composites are combinations of weather radars from many sites, they don’t always give the most current image of what is going on.
If you need to see the weather radar at your location, you will want to use a single-site radar image, which provides continuous updates across a smaller region. It takes about six minutes for the radar to make a complete 360 degree scan so the local radar may still be a little behind current conditions in a rapidly changing storm, but it’s more current than the regional loops. You can get to your local radar by going to https://radar.weather.gov/ and clicking on your local area. Tornado, severe thunderstorm and flash flood warnings are only shown on local radar. Regional radar loops are in the boxes below the main map. You can get a loop instead of a static picture using the appropriate links as long as your computer or phone can do Flash. There are also many radar apps you can get for your phone.