Forecaster summary - Issued 2019-10-30T00:25:41

The high energy (greater than 2MeV) electron flux has now seen values start to decline, although these have still peaked at over 43200pfu by 29/1800UTC. Whilst further very high values are possible during diurnal maxima on day 1, the general downward trend in values should continue, leading to the Very Active fluence (above 1e9 integrated pfu) falling to Active values (above 1e8 integrated pfu) sometime during day 1, or perhaps early day 2. This is supported by REFM, although this does appear to decrease values a little too quickly. Although any geomagnetic activity on day 1 will help to decrease these values further, albeit perhaps temporarily.

On the previous rotations, a similar response was seen from the large coronal hole that brought this enhancement, with Active fluence levels then continuing for a number of days afterwards. It follows that similar can be expected on this occasion, so whilst REFM suggests values falling below the Active level by the end of day 3, these Active values are expected to persist.