Forecaster summary - Issued 2023-05-05T00:34:34

High energy (greater than 2MeV) electron flux is expected to continue a diurnal oscillation, mainly above the High threshold, but with slightly declining peaks, until any geomagnetic storms occur to distort the radiation belts. Geomagnetic storms are most likely either late day 3 (7th) or early day 4 (8th), with the arrival of a CME, although earlier there is a chance of geomagnetic storms with the arrival of two HSS from separate coronal hole features. Therefore by the end of the forecast period Background to Moderate high energy electron flux levels are expected.

The corresponding electron fluence is expected to continue above the Active threshold (1e8 integrated flux), but with a declining trend, until late day 3 (7th) or early day 4 (8th), thereafter falling below the Active threshold. The latest MOSWOC model shows a declining trend over the next three days, which is accepted. However, the fluence is expected to remain above the Active threshold.