Summary and Forecast

Solar Summary

(last updated 13 Oct 2026 23:30 UT)

Activity 13 Oct: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 13 Oct: 136/90

Solar Forecast

(last updated 13 Oct 2026 23:30 UT)

14 Oct 15 Oct 16 Oct Activity R0, chance of R1 R0, chance of R1 R0, chance of R1 Fadeouts None expected None expected None expected 10.7cm/SSN 120/72 115/66 105/54 COMMENT: Solar flare activity was at the R0 level on UT day 13-Oct, with a C4.2 flare from the western limb the largest observed. There are currently seven numbered and one unnumbered sunspot regions on the solar disk, with Active Region (AR) 4551 (S15E21, beta-gamma) being the largest and most magnetically complex. This region has exhibited mild growth over the previous UT day, but has not been associated with any significant flare activity. Regions 4556 (N03E61, beta) and 4557 (N09E60, beta) have recently rotated onto the visible disk from the eastern limb, and have exhibited mild growth over the past 24 hours. A small unnumbered region has appeared at S08W21, and is magnetically simple. All other regions are either stable or in decline. Solar flare activity is forecast to be at the R0 level over 14-16 Oct, with a chance of R1 due to the size and growth of AR 4551. Solar radiation storm conditions were at the S0 level throughout UT day 13-Oct, with S0 conditions forecast over 14-16 Oct. No coronal mass ejections (CMEs) were observed over the previous UT day in available coronagraph imagery. The solar wind speed increased across the UT day as the Earth connected to a high speed wind stream from two geoeffective coronal holes. The solar wind speed increased from approximately 480 km/s early in the UT day to currently be ranging between 600 and 640 km/s. A weak impulse was detected in the interplanetary magnetic field strength (IMF, Bt) after 13/0105UT, possibly due to the glancing arrival of a previously observed CME. The Bt increased to reach 16 nT, before declining thereafter. The north-south component (Bz) of the IMF ranged between -8 and +15 nT over the UT day. The solar wind speed is forecast to remain elevated over 14-Oct due to the high speed wind stream effects, before declining over 15-16 Oct as the coronal holes move past a geoeffective position.

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