Forecaster summary - Issued 2021-06-20T00:18:28

The protracted and hesitant exit from current CH68 is the main feature expected to drive electron populations with any certainty in the next four days. With solar winds gradually returning to slow-ambient levels, the high energy (greater than 2MeV) electron flux will not be able to sustain its current level for much longer and will inevitably drop. Based on persistence this is estimated to happen on day 3, with a fall towards moderate then low levels leading to a decreasing trend in flux levels and a return below the Active threshold (1e8 integrated pfu) at the end of day 3 (22nd) or, more likely, on day 4 (23rd). The latest REFM output is considered to drop the values too quickly, while the recurrence-persistence model shows slightly higher probabilities, more in line with the forecast.