Summary and Forecast

Solar Summary

(last updated 25 Apr 2025 23:30 UT)

Activity 25 Apr: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 25 Apr: 164/118

Solar Forecast

(last updated 25 Apr 2025 23:30 UT)

26 Apr 27 Apr 28 Apr Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 170/124 170/124 165/119 COMMENT: Solar activity on UT day 25-Apr was at the R0 level, with no significant flaring activity. There are currently twelve numbered sunspot regions visible on the solar disk and one unnumbered region. AR4064 (N11W41, beta) is the largest region on the disk and has decayed over the UT day. AR4077 (S17E62, beta) has exhibited spot growth over the 24-hour period. AR4074 (S19W64, beta) has shown mild spot development. An unnumbered region recently appeared on the disk near N15W42 (beta) and has shown mild spot growth. All other sunspot regions are either stable or in decay. Solar activity is expected to be at R0-R1 levels over 26-28 Apr. No Earth-directed CMEs have been observed. The solar wind speed on UT day 25-Apr declined, ranging from 440 to 520 km/s and is currently near 440 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 7 nT and the north-south IMF component (Bz) range was -2 to +6 nT. The solar wind speed is expected to decline on 26-Apr, then moderately increase over 27-28 Apr.

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