Solar
FORECAST SOL: Moderate yellow MAG: Moderate yellow ION: Normal green
HomeSolarSolar ConditionsSummary and Forecast Sunday, Jun 28 2026 23:48 UT
Solar Conditions

Summary and Forecast

Solar Summary

(last updated 28 Jun 2026 23:30 UT)

Activity 28 Jun: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 28 Jun: 186/139

Solar Forecast

(last updated 28 Jun 2026 23:30 UT)

29 Jun 30 Jun 01 Jul Activity R0-R1 R0-R1 R0, chance of R1 Fadeouts Possible Possible None expected 10.7cm/SSN 175/129 180/133 175/129 COMMENT: Solar flare activity on UT day 28-Jun was at the R0 level, with a C9.5 flare at 28/2144UT from Active Region (AR) 4475 (S08W33, beta-gamma) the largest observed. This region is one of six on the visible solar disk, with region 4478 (S06E21, beta-gamma) remaining the largest. This region has shown some magnetic simplification and spot redistribution over the past 24 hours. AR 4479 (N17E05, beta-gamma) has shown some growth over the same period. All other regions on the disk appear stable or in decay. Solar flare activity is forecast to be at the R0-R1 level on 29-30 Jun, given the size and magnetic complexity of several regions on the disk. This is forecast to decline to R0, with a chance of R1 on 01-Jul, as some of the larger regions show signs of decay and magnetic simplification. S0 solar radiation storm conditions were observed on UT day 28-Jun, with the solar proton flux remaining at background levels. S0 solar radiation storms are forecast over the period 29-Jun to 01-Jul. No significant geoeffective coronal mass ejections (CMEs) were observed in available coronagraph imagery over the last 24 hours. Two CMEs were observed at 28/0400UT and 28/0548UT in SOHO/LASCO, associated with filament eruptions visible in GOES/SUVI 304A imagery. Both of these CMEs are not considered geoeffective. The solar wind speed declined over UT day 28-Jun, starting the day at 530 km/s and currently ranging between 400 and 430 km/s. The interplanetary magnetic field strength (IMF, Bt) peaked at 4 nT, with the north-south component (Bz) ranging between -3 and +3 nT over the UT day. The solar wind speed is forecast to continue to trend toward background values on 29-Jun, before rising on 30-Jun due to the impact of a CME first observed on 26-Jun. The solar wind speed will remain elevated on 01-Jul due to the ongoing effects of this CME impact.

Solar Activity levels are explained in the SWS Solar Terrestrial Glossary.

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