Forecaster summary - Issued 2018-09-23T00:05:29

The high energy electron flux (greater than 2 MeV) at GEO is likely to respond strongly through the period, following the establishment today (22nd) of the high speed stream from coronal hole 28, with Active to Very Active diurnal peaks anticipated. This will be reflected in the corresponding 24-hour fluence, which is likely to temporarily fall below the Active threshold at first on day 1 (23rd), before recovering strongly through days 2 to 4 (24th to 26th) to resume Active fluence levels. There is a chance of Very Active fluence levels developing by Day 4, although this is low confidence at present.

The REFM model indicates a rising trend to above the Active threshold from day 2 (24th) which is accepted, but the day 1 forecast is currently considered unrealistic.