Summary and Forecast

Solar Summary

(last updated 21 Apr 2026 23:30 UT)

Activity 21 Apr: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 21 Apr: 112/63

Solar Forecast

(last updated 21 Apr 2026 23:30 UT)

22 Apr 23 Apr 24 Apr Activity R0, chance R1 R0, chance R1 R0, chance R1 Fadeouts Possible Possible Possible 10.7cm/SSN 115/66 120/72 120/72 COMMENT: Solar activity on UT day 21-Apr was R0, with no solar flares. There are currently three numbered sunspot regions on the solar disk. Active region (AR) 4419 (N15W36, beta) remained mostly stable, although a new region has begun to grow underneath it. New region AR 4420 (N16E52, beta) showed fast growth and produced a number of C-class flares. All other sunspots are either stable or in decay. Solar activity is expected to be R0, chance R1 over 22-24 Apr. A CME was observed from 0312 UT associated with a filament liftoff from 0209 UT in the north. This CME is not expected to impact the Earth. No other front-side CMEs were observed in available imagery. S0 solar radiation storm conditions were observed on UT day 21-Apr. S0 solar radiation storm conditions are expected over 22-24 Apr. The solar wind environment on UT day 21-Apr was mildly disturbed due to ongoing coronal hole effects. The solar wind speed ranged from near 450 to 580 km/s. The peak total interplanetary field strength (IMF, Bt) was 8 nT and the north-south IMF component range was +5 to -6 nT. The solar wind environment is expected to return to background conditions on 22-Apr and remain so over 23-24 Apr.

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