Forecaster summary - Issued 2021-09-17T00:14:04

Earth is now experiencing an ambient solar wind environment, and any further increases to the diurnal oscillation of high energy electron flux has now passed. Other expected periodic enhancements in the period take form of coronal hole 01, and perhaps a southern hemisphere coronal hole-like feature visible at similar longitude. These alone are unlikely to significantly alter the Van Allen Belt electron populations, instead relying on the relatively low confidence arrival of the 13 September CME to end the current working week (UTC).

The chances of Active 24-hour integrated high energy electron fluence being realised rise slightly into the coming UTC weekend. This is counter to REFM output, with the rationale being the forecast's reliance on a CME rather than coronal hole activity to achieve any result.