Forecaster summary - Issued 2026-01-17T00:56:01

GOES19 high energy electron flux was Moderate but became High between 16/1205UTC to 16/2030UTC, peaking at 8700 pfu at 16/1510UTC. GOES19 high energy electron flux is expected to be Moderate to High initially Day 1 (17 Jan), then declining to Moderate levels later with the expected onset of a HSS from CH15/+, and possibly a glancing CME arrival, resulting in geomagnetic activity and solar wind increases. High flux levels are likely to return through Day 3 (19 Jan) as the geomagnetic activity eases.

The associated 24-hour fluence is expected to fall below the Active (1e8 integrated pfu) threshold early on Day 1. However, there may be a brief return to Active later Day 1 into Day 2 (17-18 Jan) depending on the timing of the arrival of the fast wind, and possibly the glancing CME. Otherwise, Active fluence may return towards the end of the period. MOSWOC REFM and recurrence do not appear to show good guidance.