Forecaster summary - Issued 2021-12-30T00:27:01

High energy electron flux levels have recently been at background or moderate levels since the high speed stream (HSS) arrival from CH38 or 39. This is likely to be due to compression of the radiation belts from the HSS. As the radiation belts de-compress, it is possible that flux levels will bounce back to reach high levels at the diurnal maxima on Days 1 and 2 (30 and 31 Dec), before another suppression is likely with the next HSS on Day 3.

As such, fluence levels may start to rise again on Days 1 and 2, with a chance of reaching Active levels during this time. REFM is suggesting a rise in fluence, although keeping levels below the Active threshold. This seems to be a good general trend, although there is low confidence in the peak fluence levels expected. The likely flux suppression on Day 3 will then probably result in a decrease in fluence levels at this time.