Forecaster summary - Issued 2025-06-05T00:20:55

The >2 MeV electron flux observed at GEO by GOES-19 has been suppressed at times over the previous days due to various solar wind enhancements, including CMEs and any potential fast wind on 04 Jun. This has brought quite variable flux, with Background to Moderate, and occasionally High values being observed. However, the extended period of above Elevated solar winds (peaking at Exceptional on 01 Jun), alongside the strong geomagnetic response has likely both compressed and charged the outer Van Allen Belt at lower orbits. As solar winds have eased, this enhanced flux has begun to expand outward, increasing the flux at GEO. 

The erratic upward trend is expected to continue on day 1 (05 Jun), however confidence then falls due to any potential further enhancements to the solar winds. These includes a chance later day 1 or day 2 (05-06 Jun) from any interaction with the fast wind from CH54, or later day 2 into day 3 (06-07 Jun) from the potential CME glance.  

The associated 24 hour fluence is just above Active at the the of issue, and is expected to continue rising day 1 (05 Jun). Confidence for this to continue then fades later in the period. This rising trend is suggested by REFM by T+48, however this is currently underestimating the forecast during the T+24 period.