Summary and Forecast

Solar Summary

(last updated 18 May 2024 23:30 UT)

Activity 18 May: R0 Flares: none. Observed 10.7 cm flux/Equivalent Sunspot Number for 18 May: 194/146

Solar Forecast

(last updated 18 May 2024 23:30 UT)

19 May 20 May 21 May Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 195/147 200/152 200/152 COMMENT: Solar activity on UT day 18-May was at the R0 level, with no significant flaring activity. There are currently nine numbered sunspot regions visible on the solar disk. AR3679 (S12W05, beta-gamma) is the most magnetically complex region on the disk and has shown slight growth in its intermediate spots. AR3685 (S14E46, beta) is the largest region on the disk and has exhibited spot development in its intermediate spots. AR3682 (N18E10, beta) has shown spot development over the UT day. All other sunspot regions are either stable or in decay. Solar activity is expected to be at R0-R1 levels over 19-21 May. Several CMEs were observed, but none are considered geoeffective. A filament eruption was observed, visible in H-alpha imagery near S45E15 at 18/2048UT. Any subsequent associated CME will be analysed once coronagraph imagery becomes available. The solar wind speed on UT day 18-May decreased, ranging from 380 to 470 km/s and is currently near 390 km/s. The peak total interplanetary field strength (IMF, Bt) was 12 nT and the north-south IMF component (Bz) range was +2 to -9 nT. Several intervals of sustained southward IMF conditions were observed over the first half of the UT day. The solar wind speed is expected to remain near background levels over 19-21 May.

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