Forecaster summary - Issued 2021-04-30T00:28:22

Electron flux levels have been mostly Moderate, but just about reached the High (1000 pfu) alert threshold at the diurnal maximum. This has been driven by the recent enhanced solar wind speeds. However solar wind speeds are now back down to ambient levels, and are expected to remain that way through Day 1 (30 Apr). As such flux levels should start to level off or drop, perhaps just reaching High levels at the diurnal maxima. Thereafter an enhancement in the solar wind speed is possible on Day 2 (01 May) due to CH50/+, although confidence is low in the level of wind speed likely to be reached. This may cause a temporary drop in electron flux on Day 2, due to the possibility of compression of the radiation belts, before a rebound is likely on Day 3 or Day 4 (02 or 03 May) if wind speeds do increase.

The associated fluence has remained fairly steady over the past 6 hours, and has remained below the Active (1e8 integrated pfu) threshold. As flux levels are expected to level off or drop over the next couple of days, fluence is expected to stay below the Active threshold through Days 1 and 2, but a rise is then possible on Days 3 or 4, although this is currently low confidence.