UTC time: 9:50:20
When to send a presto immediately?
- During or just after an X-flare occurred.
- In case of a proton event, i.e., Flux >= 10 pfu (10 MeV particles).
- When Kp > 5 or K > 5.
- When a (either front or back-side) (partial) halo CME or a strong Westward directed CME occurred. Try to find out whether the halo CME is frontsided or not, by locating the source.
- In case you observe a fast forward shock in the solar wind speed. (delta_v>20km/s, ratio_n>1.2 and ratio_B>1.2)
- In case you observe enhanced solar wind conditions which will likely lead to geomagnetic storm conditions Kp or K > 5.