Forecaster summary - Issued 2019-04-21T00:04:46

The high energy electron flux (greater than 2MeV) is expected to continue its current pattern of background to moderate levels at first during the forecast period, and perhaps continue as such throughout the four days.

Confidence in this aspect lowers beyond day two, Monday 22 April, with the possible 17 April CME affecting populations. There is then a second question mark as to the onset of the high speed stream from coronal hole 06, which may fall at the very end of the four-day period to again affect counts at geosynchronous Earth orbit.

A gradual rise in the probability of Active 24-hour integrated fluence is therefore expected as the 'error bars' increase due to these two relatively uncertain events, particularly the former (the CME).