Space Weather Forecast Headline: Chance of Moderate class flares. Minor Geomagnetic Storm likely Day 1 (28 Aug), chance of Moderate Storm.

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Solar activity has been Low over the past 24 hours, with only Common class flares. There are five regions on the visible disc. A moderately sized and magnetically complex region in the northwest forms the bulk of the flare risk, but has shown continued slight decay. Most other regions are much simpler in their magnetic structure, although a small region in the northeast has shown recent slight growth and is now classified as moderately magnetically complex. Remaining regions are also generally small and weak, except AR4517 is a moderately sized region, currently the largest region on the disc.

No significant Earth directed Coronal Mass Ejections (CME) were seen in available imagery over the last 24 hours.

Solar Wind / Geomagnetic Activity: Solar winds, as measured at L1 by SOLAR-1, were indicative of a slow wind. Solar wind speeds were Background and on a slow decline. Interplanetary Magnetic Field was weak with the north-south component also varying weakly. Geomagnetic activity was Quiet. 

Energetic Particles / Solar Radiation: The count rate of energetic particles (high energy protons) was near background, with no Solar Radiation Storms observed.

Four-Day Space Weather Forecast Summary

Solar Activity: Activity is expected to be Low to Moderate, with a chance of isolated Moderate class flares, and a slight chance of rising to Strong. The main flare risk comes from the complex region in the northwest, but new or returning regions are likely to rotate onto the disc from the far side through the forecast period, and may increase the chance of significant flares.

Solar Wind / Geomagnetic Activity: At least two Coronal Mass Ejections (CMEs) from 25 Aug may reach Earth, along with a third, much lower confidence CME. The first two are likely to give a glancing, but potentially combined, impact on Day 1 (28 Aug), with any enhancement from the third perhaps prolonging CME influence into Day 2 (29 Aug). A solar wind enhancement is still expected, arriving early Day 1, potentially peaking with speeds 450-500km/s. A further CME , which was very faint and weak and tricky to analyse, was seen leaving the Sun on 27 Aug, with an unknown source. This CME has been modelled as potentially arriving either late day 3 (30th) or early day 4 (31st Aug).

Quiet geomagnetic activity initially, but then becoming Unsettled to Active at times through the period, with Minor geomagnetic storms intervals likely, due to multiple potential CME arrivals combined with the influence of a HSS when it finally arrives. The main risk of Minor geomagnetic storm intervals is during Days 1 and 2, with a slight chance of Moderate geomagnetic storms as well.

Energetic Particles / Solar Radiation: The count rate of energetic particles (high energy protons) is most likely to continue at background levels, but with a slight chance of solar radiation reaching S1-S2/Minor-Moderate Radiation Storm.