Forecaster summary - Issued 2024-05-18T00:08:33

High energy electron flux, as observed by GOES-16 has been at largely background levels following the CME arrival early on 16 May. This trend is most likely to persist in the short term, however there is the potential for electron flux to rise and potentially reach persistently High levels later in the period, with lower orbits having been highly charged by CME arrivals over previous days. A continued rise in flux levels into Day 2 (19 May) onwards is expected although confidence is reduced due to the potential for further glancing CME influence, which may again reduce the observed flux at times. 

The associated 24 hour fluence is expected to return to a rising trend later Day 1 (17 May) onwards, increasingly likely to approach or cross the Active threshold Days 3-4 (20-21 May). MOSWOC REFM providing reasonable guidance although perhaps under representing the risk of reaching the Active threshold later in the period.