Space Weather Forecast Headline: Chance of Minor geomagnetic Storms (G1) today, perhaps extending through midweek UTC.

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Activity has been low, with a small peak Common-class x-ray flare at 13/0340UTC from the recent most-active region, now rounding the western solar horizon. 

There are four regions now visible on the Earth-facing disc, with the more active AR4549 continuing to rotate away over the western limb and a general simplification of the disk in recent hours. AR4551 remains by far the largest region on the disc. Other regions generally smaller and apparently magnetically simple, although a train of up to three regions arriving in the northeast may yet reveal further detail.

A Coronal Mass Ejection (CME) that left the Sun around 12/0500UTC from a large 'filament eruption' (arc of plasma) near S20E030 has been analysed and modelled. Forecast output indicates that although the bulk of the ejecta will pass behind Earth orbit, some flanking influence is likely on 14 October.

A further - smaller - disappearing filament was then observed at 12/1005UTC, also from the southeast at S10E030. This has also been modelled but is slow enough to lie outside the four-day forecast, perhaps serving to enhance UTC weekend activity, but is not a major forecasting consideration.

Solar Wind / Geomagnetic Activity: Solar winds saw slightly elevated conditions initially. CME arrival from approximately 13/0021UTC influencing conditions thereafter.

Solar wind speeds initially Slightly Elevated, increased slightly following CME arrival to peak at 539k/s at 13/0027UTC, and remain slightly elevated to elevated. The IMF was generally Weak to a Moderate, with a varying north-south component.

The net result of the above solar wind measures was for Quiet to Unsettled geomagnetic activity throughout.

Energetic Particles / Solar Radiation: No solar radiation storms were observed.

Four-Day Space Weather Forecast Summary

Solar Activity: There is a chance of Moderate activity initially should any isolated Moderate-class flares occur, most likely from the western solar horizon sunspot group at first, and perhaps then the one nearing the middle of the Sun. The flare risk likely declining somewhat into the period

Solar Wind / Geomagnetic Activity: There are up to three CMEs currently forecast as potentially Earth directed two of which likely remain in transit. Glancing impact from the first CME, associated with an event on the 10 October, is ongoing and likely declining, one from 12 October due as a glance on 14 October, and a second minor 12 October CME that falls outside the four-day period.

The arrival of the first CME overnight saw relatively muted geomagnetic enhancement, but it remains the case that this could combine with the expected imminent onset of faster solar winds during Day 1 (13 Oct)

A chance of G1 Minor geomagnetic storm conditions in the current UTC day from the possibly combined effects of the 10 October CME and the fast wind, perhaps peaking at a slight chance of Moderate storm G2. These conditions may be extended in time by any glancing influence of the 12 October large 'filament' on Wednesday 14 October, before a more decided reduction in risk into the latter part of the UTC working week. Any third CME from the smaller 12 October filament falls outside the period.

Energetic Particles / Solar Radiation: There is a slight chance of S1/Minor Solar Radiation Storms throughout the period.