The fast alert messages are short texts informing you about the current Space Weather. The SIDC sends them by email when ever needed.
You can click on the message-name in italic to get the latest alert.
In case of an enhanced geomagnetic K-index is measured in DOURBES (Belgium), i.e. K>4
Reduced GPS accuracy alert
A Halo CME DETECTION alert generated by the CACTus software.
A PRESTO is sent in case of:
  • an X-flare,
  • When K ≥ 5 ,
  • an upcoming strong coronal hole,
  • a halo CME,
  • a shock in the solar wind speed,
  • a proton event.
It is a text explaining what is the disturbing source and determines the effect for us, here on earth..
An ALL QUIET ALERT is sent whenever:
  • the solar X-ray output will remain below C-class level,
  • the K_p index will remain below 5,
  • the high-energy proton fluxes will remain below the
    event threshold.