Forecaster summary - Issued 2024-05-20T00:15:00

High energy electron flux, as observed by GOES-16 is at background to moderate levels. However there is the potential for electron flux to rise and potentially reach high levels later in the period, with lower orbits having been highly charged by numerous strong CME arrivals in the past week to ten days. Any rise in electron flux may be curtailed by further CME influence however, this considered most likely late day 1 (20 May) or early day 2 (21 May). 

The associated 24 hour fluence is expected to follow a generally rising trend through the period with a slight chance to reach the Active threshold by days 3 and 4 (22-23May), though dependent on the extent of any CME enhancement. In the absence of CME enhancements MOSWOC REFM looks to be providing reasonable guidance, although perhaps slightly under representing the risk of reaching the Active threshold later in the period.