:Product: Forecast Discussion :Issued: 2026 Jun 05 0030 UTC # Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center # Solar Activity .24 hr Summary... Solar activity remained at low levels, with frequent low-level C-class flares recorded from nearly all active regions across the visible disk. The single largest event during the period was a C2.6/Sf flare from Region 4457 (S09W72, Cro/beta) at 04/0357 UTC. However, the background solar x-ray flux at the start of the UTC day (0000 UTC) was measured at an elevated C3.2 level following a C5.1 flare from Region 4459 (N14E22, Dai/beta-gamma) that had peaked just prior to the turn of the day at 03/2343 UTC. There are eight numbered regions on the visible disk. Region 4455 (N15W34, Dki/beta-gamma) remains magnetically complex and continues to maintain an anti-Hale configuration, though it simplified slightly by losing the brief delta configuration observed yesterday. Flux emergence and structural growth have slowed within Region 4455, but a mixed magnetic configuration ahead of its mature, positive polarity lead spot. Region 4458 continued to display gradual growth and consolidation of its penumbral area, maintaining a complex gamma configuration. Region 4457 showed growth accompanied with new flux emergence. A new, unnumbered active region began rotating into view over the east limb at approximately N16; extreme limb foreshortening hinders any definitive characterization of its extent or complexity, and no notable flaring has yet been observed from it. All other regions on the disk were stable or in decay. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be at low to moderate levels through 07 June. While the recent simplification of Region 4455 has decreased flaring risk, the continuing complexity of that region in addition to that of 4458 and 4459 maintains a high chance for M-class (R1-R2/Minor-Moderate) flaring with a slight chance for X-class (R3/Strong or greater) events. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux at geosynchronous orbit was at low to moderate levels, with a peak flux of 468 pfu observed at 04/1345 UTC. The greater than 10 MeV proton flux remained at background levels. .Forecast... The greater than 2 MeV electron flux at geosynchronous orbit is anticipated to rise to high levels on 05 June in response to CME effects, remaining high through 07 June. While the greater than 10 MeV proton flux is expected to remain below the S1 (Minor) solar radiation storm threshold, proton enhancements are possible on 05 June due to CME shock front interactions. Solar Wind .24 hr Summary... Solar wind parameters were slightly elevated with solar wind speeds ranging mainly from 385 to 450 km/s. Total magnetic field (Bt) trended downward for the majority of the timeframe, beginning near 10 nT before ending the period below 5 nT. The North-South (Bz) component was predominantly southward early in the period, recording a maximum southward deflection of -9 nT before turning mostly northward after 04/0900 UTC which also coincided with a change in phi that had been mostly in the positive (away from the Sun) orientation since the beginning of the period. Following this, the phi angle recorded several boundary crossings later in the period before settling predominantly into the negative (towards the Sun) sector. .Forecast... Solar wind conditions are anticipated to escalate dramatically on 05 June with the arrival of the multiple 03 June CMEs. Significant solar wind enhancements are expected to persist through 05 June, with elevated and disturbed conditions continuing into early to mid-day on 06 June before continuing to trend toward background on 07 June. Geospace .24 hr Summary... The geomagnetic field was quiet to unsettled. .Forecast... Geomagnetic field conditions are anticipated to reach G3 (Strong) geomagnetic storming levels early on 05 June in response to the arrival of the multiple 03 June CMEs. There remains a chance for isolated periods of G4 (Severe) geomagnetic storming during the peak of the multi-CME passage over 05 June. Conditions are expected to drop back to active levels, with a lingering chance for isolated G1 (Minor) storming thresholds, on 06 June as CME effects gradually wane, followed by a return to mostly quiet to unsettled conditions on 07 June.