Forecaster summary - Issued 2023-09-21T00:14:47

High energy (greater than 2MeV) electron flux levels are likely to breach the 1000pfu high threshold. An uncertain forecast, with recent CME arrivals and elevated solar winds likely to have seen a build up of change within the belts and the current easing of solar winds and reduction of geomagnetic activity expected to see flux levels increasingly rise above the High threshold. Some reduction likely in the near term however, both diurnally but also given the potential for further geomagnetic activity later in the period. The 24-hour fluence is currently below the Active threshold but on a rising trend, with current MOSWOC REFM output forecast providing reasonable guidance, with an increased risk of breaching the active threshold on Day 1 (21 Sep). Forecast remains lower confidence however given uncertainties beyond this.