Forecaster summary - Issued 2021-12-19T00:40:51

The high energy (greater than 2 MeV) electron flux, as observed by GOES-16, is currently at Background to Moderate levels, and is expected to remain as such in the near term. The fact that coronal holes potentially due in the period are much-changed from last rotation means that persistence forecasting is not expected to provide a useful steer in this case. Recent STEREO A MAG and PLASTIC data has become very intermittent, but perhaps suggests a minor high speed stream is possible at Earth in the next 24 hours, probably that from the remnant coronal hole 36. This is felt unlikely to significantly alter current flux levels, with speeds of around 500km/s observed. A slight uptick in probabilities is therefore proposed, before the likely larger CH35/- perhaps arrives later in the four days (perhaps Tuesday 21 December), with the risk of Active fluence likely to peak in the middle of the forthcoming working week UTC as a result.