Forecaster summary - Issued 2023-06-21T00:26:49

The upcoming forecast carries greater-than-average uncertainty given the number of possible minor interruptions from peripheral CMEs, as hinted at in the MOSWOC Enlil ensemble, which is proving volatile from run to run.

Also complicating the electron forecast is the transition of the fast wind from CH15 into CH13. There is a chance that this may have already occurred, with both magnitude and density proving insufficient to populate the Van Allen belts. The High energy electron flux (greater than 2MeV) may have exceeded High levels over the last 24 hours but it fell sharply during the evening UTC and displayed a slightly lower diurnal peak compared to previous days. 

All considered and with an absence of significant geomagnetic activity over the following days, the high energy electron flux is most likely to become confined to low and moderate levels, the result being the fluence more likely than not to remain under the Active threshold and perhaps display a slight decreasing trend over time.