Forecaster summary - Issued 2025-10-31T13:19:49

GOES19 >2MeV electron flux is currently at moderate levels. The HSS onset from CH91/92 is later than originally anticipated and has taken a time to gradually strengthen. During the previous rotation electron flux became predominately high after connection to this coronal hole, though this was likely influenced by a CME that arrived just prior to the coronal hole’s impact. Hence confidence is fairly low, but it is likely we will start to see electron flux becoming diurnally high, with a chance of more persistent high levels developing through the period. Any CME influence on Days 2-3 (01-02 Nov) could reduce the flux once again even if it does start to rise, however confidence here is very low.

The associated 24 hr fluence is currently well below the Active (1e8 integrated flux) threshold but on a rising trend. MOSWOC REFM is verifying fairly well and is continuing this rising trend over the coming days, exceeding the Active threshold by Day 3 (2 Nov). Although confidence in the fluence forecast remains low, the risk of reaching Active levels is expected to increase through the period, consistent with forecasted increasing electron flux trends.