Space Weather Forecast Headline: Chance of Strong geomagnetic storm G3 Monday 08 June (UTC). Slight chance Minor solar radiation storm S1.

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Activity was Moderate, comprising mainly occasional low-level Common-class flares, but peaking with an isolated, long-duration Moderate-class flare from the vicinity of a small region in the southeast, peaking at 06/1401UTC. 

There are eight sunspot regions on the facing side of the Sun, evenly-spaced across the full span of the disc, with many with apparently of similar complexity. The main changes and most relevant trends seen in the period were proliferation of spots and areal growth in the northwest, although this trend slowed as the period evolved. A group in the southeast showed strong areal growth in its main leading spot, with a later spreading trend developing. A third group, in the northeast, showed slight trailing spot development and an increase in span. Other groups were generally more stable, including the visible portion of the most active group.

The Moderate-class flare was associated with a significant Coronal Mass Ejection (CME). While the bulk of the material is passing south and east of Earth, the CME is both relatively fast and wide, giving it an Earth-directed component. This is expected to arrive at Earth early on day 2 (Monday 08 June).

A more southerly part of the 'filament' complex (arc of plasma) surrounding the most active region also lifted off in the period at 07/0015UTC. This could not be correlated with any subsequent ejecta on satellite imagery, and may have been reabsorbed (to no effect at Earth). Finally, a 'prominence' (arc of plasma on the Sun's edge) lifted off the southwestern solar horizon around 07/0830UTC. While analysis has yet to be conducted, this event is thought unlikely to impinge on the Sun-Earth line.

Solar Wind / Geomagnetic Activity: Solar winds have shown a continuing slight decline in the period, in the wake of recent CME and 'coronal hole'-sourced fast wind influence.

Solar wind speeds accordingly declined from being strong to become Elevated. The number of particles in the solar wind and their associated magnetic field were both unremarkable - near their long-term averages.

The net result of the above solar wind measures was for early geomagnetic activity just shy of G1 Minor Geomagnetic Storm, but falling to become quiet with time.

Energetic Particles / Solar Radiation: No solar radiation storms were observed, howevere there remains a small proton flux enhancement in the wake of the Moderate-class flare. This peaked at 1pfu before declining (where Minor Solar Radiation Storm is 10pfu).

Four-Day Space Weather Forecast Summary

Solar Activity: Isolated Moderate-class flares are likely at first, with this risk abating slightly over the period. There is a slight chance of a Strong-class flare.

Solar Wind / Geomagnetic Activity: The main driver of geomagnetic activity in the forecast period is expected to be the sole CME en route: that associated with the Moderate-class X-ray flare on 06 June. This is expected to arrive early on day 2 (08 June) and bring a chance of Strong geomagnetic storm G3 conditions, probably easing G1-G2 (Minor-Moderate) on Tuesday 09 June before a resumption of mainly quiet geomagnetic activity by the end of the four-day period.

Energetic Particles / Solar Radiation: Proton flux saw a very slight rise as a result of the large X-ray flare on 06 June, but stayed well below the S1 Minor Radiation Storm level. This could increase further as any associated CME arrives on on day 2 (08 June), bringing a chance for a brief period of S1 Minor Solar Radiation Storms, before quickly easing after the CME arrival occurs. There is also a slight chance of further enhancements if any further notable flares occur.