Forecaster summary - Issued 2025-04-25T00:17:07

High energy electron flux (greater than 2MeV) has been at mostly Moderate levels during the last 24 hours. The recent HSS likely increased electron flux at altitudes below GEO, and the arrival of the CME earlier on 24 April may also have helped to suppress the electron flux at GEO further. As the CME and HSS influences ease and the Van Allen belts relax, diurnally High flux levels are possible. However, the longevity of any increase is low confidence given that the coronal hole CH34/+ is expected to return into the UTC weekend.

The associated 24-hour fluence is currently below Active (1e8 integrated pfu), on a generally flat trend. MOSWOC REFM suggests a slight rise in the near-term, which is felt realistic, although counts have some way to go to breach Active before any further CH34/+ influence again suppresses fluence at GEO. This latter feature is absent from REFM and it is felt less representative of likely conditions towards the end of its forecast range. All considered, there are two main periods of risk - firstly into the very start of the UTC weekend, and again to end the four days, although the chances are still Slight overall in both peaks.