Summary and Forecast
Solar Summary
(last updated 16 Aug 2026 23:30 UT)
Activity 16 Aug: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 16 Aug: 129/82
Solar Forecast
(last updated 16 Aug 2026 23:30 UT)
17 Aug 18 Aug 19 Aug Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 130/84 125/78 130/84 COMMENT: Solar flare activity on UT day 16-Aug was at the R0 level, with several C-class flares observed, the largest of which was a C8.2 flare at 16/1928UT produced by Active Region (AR) 4506 (N11W43, beta). There are currently three numbered sunspot regions visible on the solar disk and one unnumbered region. AR 4507 (N05W26, beta-gamma) is the largest and most magnetically complex region on the disk and has exhibited spot development over the UT day. Region 4506 has also shown spot growth over the 24-hour period. An unnumbered region recently appeared near N10W53 (beta) and has shown spot growth. All other regions are either stable or in decay. Solar flare activity is expected to be at R0-R1 levels over 17-19 Aug, primarily due to the magnetic complexity of region 4507. S0 solar radiation storm conditions were observed on UT day 16-Aug. S0 solar radiation storm conditions are expected over 17-19 Aug. No Earth-directed coronal mass ejections (CMEs) have been observed. A west-directed CME was observed, visible in LASCO C2 coronagraph imagery from 16/1948UT. This CME is considered to be associated with the aforementioned C8.2 flare from AR 4506. Modelling indicates this CME does not contain a geoeffective component. The solar wind speed on UT day 16-Aug decreased, ranging between 350 and 290 km/s, and is currently near 290 km/s. The peak total interplanetary magnetic field strength (IMF, Bt) was 6 nT and the north-south IMF component (Bz) range was -5 to +4 nT. The solar wind speed is expected to remain at background levels over 17-18 Aug. The solar wind speed is expected to increase on 19-Aug due to coronal hole high speed wind stream effects from a southern hemisphere coronal hole which is currently crossing the central meridian.
Solar Activity levels are explained in the SWS Solar Terrestrial Glossary.
