Forecaster summary - Issued 2026-06-08T00:16:09

The GOES19 high-energy (>2MeV) electron flux rose in response to the recent CME and fast wind arrivals, becoming Moderate to High through 07 June. However, the expected CME arrival early on 08 June brings a likely drop-out of the observed flux at GEO. Any subsequent recovery on days 2-4 (09-11 June) is low confidence, however further periods of eventual High flux are likely, but perhaps not until later in the four-day period.

The associated 24-hour fluence is expected to continue to rise at first, with initially Active fluence on day 1, as supported by MOSWOC REFM. This model remains too quick with its rise, however the eventual level reached on day 1 looks feasible - being the low end of Active before the CME arrives. Active fluence is likely to be short-lived due to the anticipated CME arrival during the UTC morning of 08 June. REFM does not have any awareness of the CME forecast, so the model will become unreliable at this stage. Later day 2 and into day 3, the fluence is expect to rise again, bringing a further Slight Chance of rising to the Active threshold, although the bulk of any eventual peak will likely fall after midweek UTC.