Forecaster summary - Issued 2023-03-11T01:14:28

High energy electron flux (greater than 2MeV) has been at mostly moderate levels through the last 24 hours, with an incursion to high levels for a time. The long-lived high speed streams (HSS) related to coronal holes 81 and 82 have now waned. In the absence of further coronal holes and with limited geomagnetic activity, electron flux is expected to continue to follow a declining trend through the period, with peaks increasingly likely to be below the high threshold through the period. The BAS radiation belt model is suggesting high electron populations in lower Earth orbits, but with no significant geomagnetic activity forecast and solar wind speeds approaching background levels there appears to be limited mechanisms for the electrons to reach higher orbits.

Electron fluence edged further down and remains below the Active threshold. Levels will probably continue to follow a gradual declining trend through the period, with no inputs or enhancements into the belts forecast from high speed streams or CMEs. The output from Met Office REFM is considered to be giving a good guide, and probabilities for reaching Active fluence are relatively low.