Forecaster summary - Issued 2023-06-01T00:09:18

High energy electron flux (greater than 2MeV) has varied between moderate and background levels, as the bulk of the recent electron accumulations in the radiation belts are modelled to be at a sub-GEO orbit. Initially on Day 1 (1 Jun) background to moderate levels are expected in the absence of any significant modifying factors. The likely onset high speed streams associated with coronal holes CH08/+ and CH09/+ from late on Day 1 or into Day 2 (1/2 Jun) may lead to an increasing risk of exceeding the high (1e3pfu) threshold on diurnal peaks, with a rising trend expected into Days 3 and 4 (3/4 June).

Associated 24 hour fluence values are likely to show an increasing trend through the period, especially following the onset of the forecast high speed streams into Days 3 and 4 (3/4 Jun). Active (1e8 integrated pfu) thresholds are increasingly likely to be exceeded by the end of the period. REFM model not currently viewed as providing good guidance.