Relativistic Electron Enhancement(REE)alerts provide information of the cumulative fluence of the high-energy(>2 MeV) electrons in geosynchronous orbit. There are two types of REE alerts: Alert and Summary. An Alert is issued in real time when the cumulative fluence exceeds the threshold; the next day will give a summary for yesterday containing the biggest value of cumulative fluence. There are three-level alerts according to value of the cumulative fluence. The yellow color means the value is between 108pfu and 109 pfu, orange color means the value is between 109 pfu and 1010 pfu, red color means the flux is above the 1010 pfu. If the color is green, it means the value is under 108pfu.
From the web we can see REE alerts 27-day-cycle review and search history alerts.