Forecaster summary - Issued 2022-08-18T00:09:07

High energy electron flux (greater than 2MeV) will start the period at Background to Moderate levels. During Day 1 (18th) ongoing high speed stream and CME influence is expected to suppress flux levels due to both geomagnetic effects and deformation of the van Allen belt. A further potential CME arrival later Day 1 or early Day 2 (18-19th) may continue the suppressed flux levels, with further possible glancing CME effects through the 19th into early Day 3 (20th). A rise is possible during Day 3 (20th) as geomagnetic activity begins to subside, but confidence is low by this time.

Electron fluence values will start above the Active (1e8 integrated pfu) threshold, but are likely to drop sharply with the ongoing HSS and CME influences, probably below Active levels. They are most likely to stay below during Days 1 and 2, perhaps with a rise later on Day 3, although this is low confidence. REFM forecast values are currently too low, and this model won't be taking account of the CME effects. Therefore REFM trends should not be relied upon through this period.