Weather radar sites across Europe, property of their respective providers, integrated into our system for real-time monitoring of precipitation and storm activity. Clicking on an orange radar site reveals the available capabilities if/when available:
Reflectivity: shows precipitation intensity and structure.
Velocity: (where available) shows radial wind speed, used to detect rotation, divergence, and shear.
When data for the radarsite has not been updated for an hour or more, the radar icon changes from orange to blue, indicating the radarsite is offline.
Weather radars transmit microwave pulses that scatter back when encountering precipitation particles. The returned signal is analyzed to produce:
Reflectivity (dBZ): intensity of returned power, proportional to the size and number of hydrometeors. Typical ranges:
• 0–15 dBZ: very light drizzle / non-meteorological
• 20–30 dBZ: light rain
• 30–40 dBZ: moderate rain
• 40–50 dBZ: heavy rain
• 50–60 dBZ: very heavy rain (severe downpours)
• 60+ dBZ: hail - large hail / extremely intense convective precipitation
Radial Velocity: measures the component of wind toward or away from the radar.
• Positive = moving away.
• Negative = moving toward.
• Monitoring thunderstorms, heavy rain, hail, and snow.
• Tracking mesoscale features such as gust fronts and squall lines.
• Velocity data helps identify severe storm signatures such as rotation, downbursts, shear and storm-relative winds.
• Beam overshooting at long ranges reduces detection of low-level phenomena.
• Ground clutter, anomalous propagation, and attenuation can produce false signals.
• Quality of radar-imagery is station & country-dependent.
• Radars can go down (maintenance, malfunction...).
