Summary and Forecast

Solar Summary

(last updated 04 Aug 2025 23:32 UT)

Activity 04 Aug: Moderate Flares Max Fadeout Freq. Sectors M2.0 0457UT possible lower E. Asia/Aust. Observed 10.7 cm flux/Equivalent Sunspot Number for 04 Aug: 142/96

Solar Forecast

(last updated 04 Aug 2025 23:32 UT)

05 Aug 06 Aug 07 Aug Activity R1, chance R2 R1, chance R2 R1, chance R2 Fadeouts Probable Probable Probable 10.7cm/SSN 145/99 145/99 140/94 COMMENT: Solar activity on UT day 04-Aug was at the R1 level due to an M2.0 flare at 04/0457UT, produced by AR4168 (N06E06, beta-gamma-delta). There are currently five numbered sunspot regions visible on the solar disk. AR4168 has shown spot growth over the UT day and become more magnetically complex with possibly up to two delta spots. AR4161 (S16W27, beta) and AR4165 (N12E07, beta) have both shown some growth over the UT day. All other sunspot regions are either stable or in decay. Solar activity is expected to be at R1 levels with a chance of R2 over 05-07 Aug. S0 solar proton conditions were observed on UT day 04-Aug. S0 solar proton conditions are expected over 05-07 Aug. A diffuse CME was observed in SOHO C2 and STEREO A imagery from 04/0800UT and is likely associated with the M2.0 flare produced by solar region AR4168 and has been modelled as a possible glancing impact on 07/0800UT +/- 12 hours. The solar wind speed on UT day 04-Aug mildly decreased, ranging from 530 to 430 km/s and is currently near 440 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 9 nT and the north-south IMF component (Bz) range was -7 to +6 nT. The solar wind speed is expected to remain steady near background levels over 05-06 Aug before possibly increasing from late on the 07 Aug as a coronal hole becomes geoeffective.

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