Forecaster summary - Issued 2026-03-23T00:36:55

GOES‑19 high‑energy (>2 MeV) electron flux has remained largely suppressed due to HSS influence from CH33/-, although at the diurnal maximum briefly peaked 1309pfu at 22/1430UTC. Similar conditions are likely to continue through Day 1 (23 Mar). From Day 2 (24 Mar) onwards flux levels are expected to generally increase as geomagnetic activity and solar wind pressure slowly wanes, with increasing potential for periods above High levels, especially during the diurnal maximum. 

The associated 24hr electron fluence is expected to remain below the Active threshold (1e8 integrated flux) initially, but with a rising trend expected, such that perhaps from later Day 2 (24 Mar) fluence levels may breach the Active threshold. Active fluence then becomes increasingly likely through to the end of the period. MOSWOC REFM is now a close match to observed values, and the signal for a rising trend into the Active threshold through the period is considered good guidance.