Summary and Forecast

Solar Summary

(last updated 26 Jul 2024 23:30 UT)

Activity 26 Jul: R1 Flares Max Fadeout Freq. Sectors M1.7 0442UT possible lower E. Asia/Aust. Observed 10.7 cm flux/Equivalent Sunspot Number for 26 Jul: 176/130

Solar Forecast

(last updated 26 Jul 2024 23:30 UT)

27 Jul 28 Jul 29 Jul Activity R0-R1 R0-R1 R0-R1 Fadeouts Possible Possible Possible 10.7cm/SSN 170/124 165/119 165/119 COMMENT: Solar activity on UT day 26-Jul was R1, with an isolated M1 solar flare from AR3761(S10W80, beta). This small region is about to rotate off disk. There are currently ten numbered sunspot regions on the solar disk. Solar region AR3762(S12W12, beta-gamma) is currently the largest region on the visible solar disk and has shown decay in its trailers and development in some of its leader spots. This region produced C class flare activity. In the southeast solar quadrant a group of solar regions AR3765(S11E36, beta), AR3766(S22E37, beta) and AR3767(S09E48, beta-gamma) are growing. All other sunspot regions are either stable or in decay. Solar activity is expected to be R0-R1 over 27-29 Jul. A small 7 degree long solar filament located at S25W08 erupted over the interval 26/1900-2000UT. No Earth-directed CMEs were observed on 26-Jul. Two very narrow west directed CMEs were observed in LASCO imagery from 26/0312UT and 26/0948UT. These CMEs could not be correlated to on disk activity and are currently assumed to be associated with either solar limb or far side activity. No CME appeared associated with the small filament eruption. S0 solar radiation storm conditions were observed on 26-Jul. S0 solar radiation storm conditions are expected over 27-29 Jul. The solar wind speed gradually increased on 26-Jul from near 450 to 600 km/s during the interval 26/0000-0500UT and is currently near 500km/sec. The peak total interplanetary field strength (IMF, Bt) was 16 nT and the north-south IMF component range (Bz) was +8 to -13 nT. The solar wind IMF Bz component showed an interval of oscillation 26/0000-0240UT followed by a southward interval 26/0325-0520UT. The increase in wind speed and later drop in density implies a coronal hole wind stream, though none appears currently evident on the solar disk west of the solar central meridian, whilst the interval of oscillation of the IMF Bz component early in the UT day possibly suggests a solar sector boundary crossing, though the solar wind toward and way ecliptic plane magnetic field vector angle does not show a sustained change in orientation following the oscillating Bz interval. The solar wind is expected to remain enhanced for today with a slight declining trend and is expected to be somewhat disturbed at times during 27-29 Jul due to the possible arrival of weak glancing blows from recent CMEs.

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