Radio Burst at 245 MHz and the Forecast of Solar Activities

The data of the radio burst at 245 MHz issued by the Space Environment Service Center(in Boulder, USA) are used for the real-time alert of solar activities. Some characteristics of the radio burst at the frequency of 245 MHz and the relation beween the narrow-band bursts at meter wavelengths and other solar activities are introduced. The reason for the real-time alert with the burst at 245 MHz is also discussed.