Forecaster summary - Issued 2021-12-08T00:43:19

The high energy electron flux (greater than 2 MeV) as observed by GOES-16 has reached the top end of Moderate levels during the last 24 hours, and is forecast to persist near this level, with a low chance of seeing peak values reach High levels. There is the potential for a dropout in values from any geomagnetic activity due to CME and/or CH29 high speed stream arrival on Days 2 and 3 (09 and 10 Dec). This may be followed by an increase in values on Day 4 (11 Dec), but this is low confidence.

The associated fluence may rise slightly on Day 1 (08 Dec), but is likely to stay below Active with only a slight chance of rising above. Thereafter fluence may well drop in the wake of CME or HSS arrival, before a possible recovery on Day 4. REFM is currently suggesting a rise close to Active levels on Day 1, but this is considered to be too high with a continuation of fluence below the Active threshold most likely.