Forecaster summary - Issued 2025-09-17T00:17:23

High energy (greater than 2MeV) electron flux as observed by GOES-19 is currently at Moderate to High levels, rising after recent fast wind wind onset and geomagnetic activity, which potentially including some influence of a CME. These conditions have likely charged the outer Van Allen Belt, and as this eases back to incorporate GEO through the coming 1-2 days, the observed flux is expected to rise to be predominately High through day 1 (17 Sep).  No other enhancements or causes for drop out are currently forecast.

The associated 24 hour fluence is currently near the Active level, but is expected to see a rising trend, expected to increasingly rise above the Active threshold during day 1 (17 Sep) and is expected to remain Active day 2 onward (18-20 Sep) although confidence does reduce towards the end of the period. MOSWOC REFM is currently over-estimating the observed fluence, however this does support a likely rise. 27-day recurrence is conversely under-estimating the likely fluence, however this likely due to the fast wind onset being earlier than on the previous rotation with a stronger geomagnetic impact.