Forecaster summary - Issued 2025-07-03T00:11:17

GOES-19 high energy (greater than 2 MeV) electron flux levels have reached high levels over the last few days following the weakening of the HSS originating from CH59/– and subsequent decline in geomagnetic activity. The geomagnetic forecast is currently low confidence as an anticipated CME arrival is now well overdue, with any HSS connection to CH61/- likely to be weak. Either of these features could have the effect of compressing the electron belts back below GEO, reducing the observed electron flux, however there is the possibility that this may not occur and flux may continue at moderate to high levels. 

Fluence is currently above the Active (1e8 integrated pfu) level. If we do see CME influence or a stronger HSS from CH61, then the fluence is likely to drop during Days 1-2 (03-04 Jul). However, if this does not materialise, then fluence is more likely to stay above the Active threshold. Confidence here is low until we see how the CME and HSS forecast plays out in the next 24-36 hours. MOSWOC REFM is forecasting a steady decline in fluence, which looks to be too early even if we should experience CME or HSS influence.