Space Weather Forecast Headline: Chance of Moderate-class X-ray flares. Chance of Minor solar radiation storm Day 1 (26 May).

Analysis of Space Weather Activity over past 24 hours

Solar Activity: Solar activity has been Low with Common-class flares observed in the past 24 hours. 

There are currently nine sunspot regions on the visible disc. Of most interest are two clusters of spot regions both located in the southeast disc. The westernmost of these consists of a moderate size bipolar and unipolar region. The moderate size bipolar region has shown some further development, particularly in its lead and intermediate portions, although has a relatively simple magnetic structure at present. The moderate size unipolar spot region to its southeast appears stable currently. The second clustering of regions lies further east and consists of two bipolar and two unipolar regions. The westernmost of these groups is a fairly large unipolar spot but showing only small changes in evolution. The other spot groups are smaller and magnetically simple regions, again showing only small changes in development at present. Also, remaining spot regions located in the northeast and southwest quadrant are similarly small and magnetically simple.

A significant far sided eruptive event appears to have occurred at around 25/2200UTC, with a Coronal Mass Ejection (CME) beginning to emerge from beyond the northwest limb in latest coronagraph imagery. No Earth directed CMEs were observed.

Solar Wind / Geomagnetic Activity: Solar winds showed background conditions at first perhaps with some weak coronal hole influence later. Wind speeds ranged between 320-350km/s until around 25/1530UTC, then rose to 400-430km/s. The Interplanetary Magnetic Field was mainly weak, but briefly reached moderate after 25/1530UTC. The north-south component varied weakly. Geomagnetic activity was mostly Quiet (Kp 1-2), but with and Unsettled interval (Kp 3) 25/0000-0300UTC.

Energetic Particles / Solar Radiation: No solar radiation storms were observed, although the the time of writing some recent enhancement to background levels has been observed following the far sided eruptive event mentioned earlier.

Four-Day Space Weather Forecast Summary

Solar Activity: There is an increasing chance of isolated Moderate-class flares, initially most likely from regions currently on the disc, but with an increasing component from far side region(s) rotating onto the east limb.

Solar Wind / Geomagnetic Activity: No CMEs currently feature in the forecast.

Some weak influence from a small southern coronal hole may have already occurred with Background solar winds rising to Slightly Elevated. Further mild enhancements are possible through Days 1-3 (26-28 May) from southern coronal holes, with speeds perhaps reaching up to 500 km/s.

Mainly Quiet geomagnetic activity is expected at first, but activity is likely to become Unsettled to Active with coronal hole influence, most probably on Days 2-3, with a slight chance of G1/Minor Storm intervals.

Energetic Particles / Solar Radiation: Solar radiation levels are most likely to remain at background, although there is a chance of a S1/Minor solar radiation storm on Day 1 (26 May).