Summary and Forecast

Solar Summary

(last updated 20 Jun 2026 23:30 UT)

Activity 20 Jun: R1 Flares Max Fadeout Freq. Sectors M1.3 0151UT possible lower West Pacific M1.0 1500UT possible lower South American/ Atlantic Observed 10.7 cm flux/Equivalent Sunspot Number for 20 Jun: 113/64

Solar Forecast

(last updated 20 Jun 2026 23:30 UT)

21 Jun 22 Jun 23 Jun Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 115/66 120/72 120/72 COMMENT: Solar activity on UT day 20-Jun was R1, with M1.3 and M1.0 class solar flares. The first flare originated from active region (AR) 4472 (S12E53, beta) and the second flare from a region behind AR4472, yet to be fully rotate into view and receive a number. There are currently four numbered sunspot regions on the disk, all of which are currently stable. Exact assessment cannot yet be made on the new region due to low visibility, however solar activity is expected to be R0-R1 over 21-23 June due to this region. A slow moving partial halo CME was observed from 20/0212 UT associated with the M1.3 flare on the eastern limb. This CME is not expected to impact the Earth. A second CME directed to the solar northeast was observed shortly after at 0312 UT, but has been assessed as farside and therefore not Earth-directed. No other CMEs were observed on 20-Jun. S0 solar radiation storm conditions were observed on UT day 20-Jun. S0 solar radiation storm conditions are expected over 21-23 Jun. The solar wind environment on UT day 20-Jun was near background levels. The solar wind speed ranged from 360-420 km/s. The peak total interplanetary field strength (IMF, Bt) was 8 nT and the north-south IMF component (Bz) was +6 to -6 nT. The solar wind environment is expected to mostly remain near background levels over 21-23 Jun, but weak coronal hole connection may give way to slightly enhanced wind speeds by the end of the period.

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