Summary and Forecast

Solar Summary

(last updated 18 Jul 2026 23:30 UT)

Activity 18 Jul: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 18 Jul: 110/60

Solar Forecast

(last updated 18 Jul 2026 23:30 UT)

19 Jul 20 Jul 21 Jul Activity R0, chance of R1 R0, chance of R1 R0, chance of R1 Fadeouts None expected None expected None expected 10.7cm/SSN 115/66 120/72 120/72 COMMENT: Solar flare activity on UT day 18-Jul was at the R0 level, with no significant flaring activity. There are currently two numbered regions visible on the solar disk and one unnumbered region. Active Region (AR) 4489 (S07W01, beta) is the most magnetically complex on the disk and has been stable over the UT day. Region 4491 (S11E33, alpha) is also stable. An unnumbered region is rotating over the eastern limb near N15E88 (alpha). This region is possibly the return of region 4479, which produced R3 level flare activity on its previous rotation. Solar flare activity is expected to be at the R0 level over 19-21 Jul, with a chance of R1. S0 solar radiation storm conditions were observed on UT day 18-Jul. S0 solar radiation storm conditions are expected over 19-21 Jul. No Earth-directed coronal mass ejections (CMEs) have been observed. The solar wind speed on UT day 18-Jul decreased, ranging from 355 to 320 km/s and is currently near 325 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 5 nT and the north-south IMF component (Bz) range was -3 to +4 nT. A narrow, elongated trans-equatorial coronal hole spanning both solar hemispheres is currently visible in the eastern solar hemisphere, but is not expected to impact the solar wind during the forecast period. The solar wind speed is expected to remain at background levels over 19-21 Jul.

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