Forecaster summary - Issued 2021-08-24T00:28:06

The high energy electron flux (greater than 2MeV) is expected to remain at background to moderate levels until the arrival of the fast wind originating from CH92/+ on Day 1 (24th). With solar wind speeds of 450-550 km/s, the probability of seeing a significant increase in the electron population should be rather high. However, on the previous rotation and under similar conditions, the Van Allen belts barely reached high levels. A cautious approach is advocated, with any rise most likely to be modest. The electron flux is therefore expected to increase to moderate levels at the end of Day 1 (24th), perhaps reaching high levels during the diurnal cycle on Days 2-4 (25th-27th).

The associated 24-hour electron fluence is expected to rise accordingly whilst remaining well below the Active threshold. The latest REFM output is likely slightly underplaying the rising trend expected on Days 2-4 (25th-27th).