Forecaster summary - Issued 2026-04-30T00:12:31

GOES19 High energy (>2 MeV) electron flux is showing a steady tendency in its diurnal oscillation, staying at mostly moderate levels. This is likely to remain at background to moderate levels as the onset of the HSS from CH48/- during Day 1 (30 Apr) will keep the outer Van Allen belt compressed below GEO into at least Day 2 (01 May). As the HSS begins to ease later in the period, there is the possibility of electron flux increasing, perhaps reaching high levels at the diurnal peak. Confidence is fairly low however, with electron response depending on wind speeds and geomagnetic activity associated with this feature.

The 24 hour integrated fluence is expected to remain below the Active (1e8 integrated pfu) threshold at first, but with a rise possible during Days 3-4 (02-03 May), giving a chance of reaching Active by the end of Day 4. MOSWOC REFM is forecasting below Active fluence during the next three days, which is accepted. Recurrence is not expected to provide a good guide to fluence values as the HSS from CH48/- is not expected to be as significant as it was on the previous rotation.