Viewing archive of Thursday, 28 October 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Oct 28 1231 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
28 Oct 2021	112	002
29 Oct 2021	100	001
30 Oct 2021	090	007

Bulletin

Solar flaring activity was moderate during the last 24 hours, with two M-class and several C-class flares detected. NOAA Active Region (AR) 2887 produced an M1 flare today at 07:30 UT and an M2 flare today at 10:37 UT. It also produced numerous C-class flares during the last 24 hours. NOAA AR 2891 produced a few C1 and C2 flares during the last 24 hours. One or more M-class flares are likely for the next 24 hours, with a remote possibility for an X-class flare.

No Earth-directed CMEs have so far being seeing in coronograph images. However, geo-effective CMEs might be detected in the next 24 hours as images from satellite coronographs (such as SOHO/LASCO-C2 and STEREO/Cor2) will become available. This is because of the flaring activity of the last few hours that can be seen in EUV imagers.

The greater than 10 MeV proton flux was at nominal levels over the past 24 hours and is expected to remain so for the next 24 hours. The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold and is expected to remain below this threshold during the next 24 hours. The 24h electron fluence was at nominal levels and is expected to remain so.

The solar wind speed (as measured by DSCOVR) dropped gradually from 420 to 290 km/s during the last 24 hours. The total magnetic field decreased from 9 nT to 1 nT, while the Bz varied between -5 and +6 nT in the last 24 hours. The interplanetary magnetic field phi angle was predominantly in the negative sector (directed towards the Sun) during the last 24 hours. The solar wind conditions are expected to remain in the slow solar wind regime for the next 24 hours.

Geomagnetic conditions were globally and locally quiet (NOAA Kp 0-1 and K Dourbes 0-2) during the last 24 hours. Geomagnetic conditions are expected to remain quiet in the next 24 hours.

Today's estimated international sunspot number (ISN): 093, based on 23 stations.

Solar indices for 27 Oct 2021

Wolf number Catania	///
10cm solar flux	111
AK Chambon La Forêt	005
AK Wingst	003
Estimated Ap	002
Estimated international sunspot number	099 - Based on 23 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

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