If the radar animation of the last hours shows local thunderstorms or precipitation cells forming and disappearing in an irregular manner, then the forecast is not vey accurate. The forecast works very well when weather fronts or large organized precipitation structures are moving regularly, without disappearing or being created. Real weather is more complex than just the displacement of existing precipitation cells. Longer forecasts are not possible, as new precipitation cells are developing or existing ones are disappearing within a short time. This so called precipitation nowcast is the most accurate precipitation forecast possible but the forecast horizon is limited to about an hour. The rain/snow forecast is computed by estimating the movement of precipitation cells observed by radar and extrapolating this movement into the future. View rain radar and maps of forecast precipitation, wind speed. Moreover, some countries do not operate a weather radar network, and in those countries satellite data is used to estimate rainfall, which is less accurate than a realtime weather radar.Ĭalifornia: How accurate is the radar based forecast? Weather forecasts and LIVE satellite images of Los Angeles, California, United States. Note that lightning is not shown on the forecast, as it cannot be predicted. Light blue indicates drizzle, blue a medium intensity, and red and yellow indicate very strong precipitation, usually associated with thunderstorms.Ĭurrent lightning strikes are marked with small orange dots on the map (Europe only). The different colours indicate the intensity of rainfall or snowfall. The radar map is updated every 5 minutes with a new radar observation. Since hail can cause the rainfall estimates to be higher than what is actually occurring, steps are taken to prevent these high dBZ values from being converted to rainfall.The weather radar ( California) shows where it is currently raining or snowing. Hail is a good reflector of energy and will return very high dBZ values. These values are estimates of the rainfall per hour, updated each volume scan, with rainfall accumulated over time. Depending on the type of weather occurring and the area of the U.S., forecasters use a set of rainrates which are associated to the dBZ values. The higher the dBZ, the stronger the rainrate. Typically, light rain is occurring when the dBZ value reaches 20.

The scale of dBZ values is also related to the intensity of rainfall. The value of the dBZ depends upon the mode the radar is in at the time the image was created. Notice the color on each scale remains the same in both operational modes, only the values change. The other scale (near left) represents dBZ values when the radar is in precipitation mode (dBZ values from 5 to 75). One scale (far left) represents dBZ values when the radar is in clear air mode (dBZ values from -28 to +28). Each reflectivity image you see includes one of two color scales. The dBZ values increase as the strength of the signal returned to the radar increases. So, a more convenient number for calculations and comparison, a decibel (or logarithmic) scale (dBZ), is used. Reflectivity (designated by the letter Z) covers a wide range of signals (from very weak to very strong). 'Reflectivity' is the amount of transmitted power returned to the radar receiver. Live wind, rain, radar or temperature maps, more than 50 weather layers, detailed forecast for your place, data from the best weather forecast models with. The colors are the different echo intensities (reflectivity) measured in dBZ (decibels of Z) during each elevation scan.

Los angeles weather radar live