Garmin 400 Series Pilot's Manual Addendum

Also see for nuvi 500-Series: User manual Pilot's guide Owner's manual Quick reference guide Owner's manual

Contents

Garmin 400 Series Pilot's Manual Addendum Manual pdf 20 page image

12Section 2NEXRAD OverviewSection 2: NEXRAD OverviewNEXRAD DescriptionWSR-88D weather surveillance radar or NEXRAD (NEXt generation RADar) is a Doppler radar systemthat has greatly improved the detection of meteorological events such as thunderstorms, tornadoes, andhurricanes. An extensive network of NEXRAD stations provides almost complete radar coverage of thecontinental United States, Alaska, and Hawaii. The range of each NEXRAD is 124 nautical miles.NEXRAD AbnormalitiesThere are possible abnormalities regarding displayed NEXRAD images. Some, but not all, of thoseinclude:• Ground Clutter• Strobes and spurious radar data• Sun strobes, when the radar antenna points directly at the sun• Military aircraft deploy metallic dust (chaff) which can cause alterations in radar scans• Interference from buildings or mountains, which may cause shadowsNEXRAD LimitationsCertain limitations exist regarding the NEXRAD radar displays. Some, but not all, are listed for theuser’s awareness:• NEXRAD base reflectivity does not provide sufficient information to determine cloud layers orprecipitation characteristics (hail vs. rain, etc).• NEXRAD base reflectivity is sampled at the minimum antenna elevation angle. An individualNEXRAD site cannot depict high altitude storms at close ranges, and has no information aboutstorms directly over the site.• Depending on the amount and complexity of the weather data being received, the resolution of thedisplayed NEXRAD data may be as high as 2 km (depending on available system memory).CAUTION: NEXRAD weather data is to be usedfor long-range planning purposes only. Due toinherent delays and relative age of the data thatcan be experienced, NEXRAD weather data cannotbe used for short-range avoidance of weather.