Have you ever seen something that looks like a golf ball on stilts or maybe a huge soccer ball? If so, then you have seen a radome. But what is their purpose?
The word radome comes from the combination of radar and dome. They protect the radar inside from weather and the elements. In the image below, you can see a classic National Weather Service (NWS) radar and an inlaid photo of the radar dish inside. The dish rotates within the dome and elevates as it does in order to get a full image of the weather surrounding it. This is the data you see when you look at your RadarScope app.
Radomes are made of very light material, usually fiberglass. They are designed to not attenuate or disrupt the radar signal being transmitted. Occasionally, weather radars get hit by the storms they are trying to scan. Here, you can see what a severe thunderstorm can do to a radome when hit with very strong winds. Obviously, this makes the radar unusable while repairs are made and spare parts aren’t easy to find.
These radomes are meant to withstand winds of up to 134 mph. However, when one encounters a strong cat 5 hurricane and sits at a higher elevation, a lot can go wrong. Flying debris, along with high winds, can totally destroy not only the radome but also the radar dish inside.
— NWS San Juan (@NWSSanJuan) September 24, 2017
All NWS radars are currently going through the Service Life Extension Plan (SLEP) in order to keep them in working order as parts begin to wear down. It is unknown if that plan accounts for catastrophic failure. For now you can expect this radar to be down for a long time.
— RadarScope (@RadarScope) September 20, 2017
— RadarScope (@RadarScope) September 25, 2017