Forecaster summary - Issued 2023-10-17T00:17:27

Electron flux observed by GOES-16 at GEO are currently at background, however the Van Allen belts are likely to see electron population increase day 1 and day 2 (17-18 Oct). This is primarily due to the onset of fast winds of CH60/+ on day 1 (17 Oct), but with a more uncertain influence from any CME glance that occurs on day 2 (18 Oct). As solar wind pressure then eases the flux at GEO is likely to rise day 3 and day 4 (19-20 Oct), becoming more persistently Moderate with a chance of reaching High, mainly at diurnal peak periods.  These enhancements are low confidence however, and it is possible that background electron flux will persist throughout.

The associated fluence is likely to remain below the Active threshold, however confidence decreases later in the period due to the potential for enhancement from CH60/+ fast wind and the CME impact. REFM is giving a good guidance to expected conditions in the absence of any enhancement, however this will become unreliable once any fast wind or CME arrival occurs.