Forecaster summary - Issued 2021-09-26T12:01:54

The high energy (greater than 2 MeV) electron flux as observed by GOES16 at GEO is mainly at background, and expected to remain at this level until day the arrival of the fast wind of CH05 and potential CMEs from midday day 1 (26th) and through day 2 (27th). Thereafter the flux forecast becomes very uncertain but likely rising to become High for much of the period. This is low confidence however, with a chance for observed flux at GEO dropping out at times as the Van Allen belts become compressed by further CME arrivals or fast wind enhancements. 

The 24 hour associated fluence will see a delayed response, only rising through day 2 to likely be above the Active (1e8 integrated pfu) threshold days 3 and 4 (28th and 29th). REFM is currently over-estimating fluence values, but is indicating fluence staying below the Active threshold. Confidence in the model signal falls to very low by day 2, as this doesn't take account of either CME arrivals of the larger and more notable coronal hole (CH05) on this rotation.