Date: 2025 Jun 04 1230 UTC
Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
Solar activity reached moderate levels due to an M1.4 flare at 03/1303 UTC from newly numbered Region 4105 (S14E64, Dai/beta). The majority of the C-class flares were attributable to this region, however it currently is too close to the E limb for accurate spot/magnetic classification. Slight Decay was observed in Regions 4099 (S14W57, Dai/beta) and 4100 (N10W48, Eki/beta-gamma).Other activity included an approximate 25 degree filament eruption, centered near N30E05 that began around 03/0224 UTC. An associated, slow moving CME was first visible in SOHO/LASCO C2 imagery at 03/0700 UTC off the NE limb. Model estimates indicated glancing influences around mid to late on 07 Jun.
Forecast: Solar activity is likely to reach moderate levels (R1-R2, Minor-Moderate) with a slight chance for X-class flares (R3-Strong) on 04-06 Jun.Energetic Particle The greater than 2 MeV electron flux was at moderate to high levels with a peak flux of 3,370 pfu at 03/0355 UTC. The greater than 10 MeV proton flux declined from approximately 3 pfu to near 1 pfu, well below the S1 (Minor) threshold.
Forecast: The greater than 2 MeV electron flux is expected to continue at moderate to high levels through 06 Jun. There is a slight chance for an S1 (Minor) proton event on 04-06 Jun.
Solar wind parameters remained enhanced with declining CME effects and CH HSS influences. Total field was generally between 5 to 9 nT. The Bz component was variable with a few brief southward deflections. Solar wind speed averaged near 550 km/s. Phi angle was mostly negative.
Forecast: Solar wind parameters are expected to continue to be enhanced through 06 Jun as CME influence transition into HSS activity. Solar wind speed will likely remain enhanced around 500-600 km/s.
Forecast: Unsettled to G1 (Minor) geomagnetic storming is expected on 04-05 Jun as CME effects transition into HSS activity. Quiet to active levels are expected on 06 Jun as HSS influence persists