Viewing archive of Wednesday, 12 May 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 May 12 1257 UTC

SIDC Forecast

Solar flares

Quiet conditions (<50% probability of C-class flares)

Geomagnetism

Moderate (ISES: Major) magstorm expected (A>=50 or K=6)

Solar protons

Quiet

	10cm flux	Ap
12 May 2021	076	050
13 May 2021	079	067
14 May 2021	082	040

Bulletin

Solar activity was low over the past 24 hours. NOAA Active Region (AR) 2822 (Catania sunspot group 93, mag. configuration Beta-gamma) produced a C1.5 flare at 09:15UT. NOAA AR 2823 (Catania sunspot group 94) is smaller and less active producing only B-class events. Both NOAA AR 2822 and 2823 will decay in the next 24 hours. The newly-labelled NOAA AR 2821 has not rotated to solar disk sufficiently to produce any detectable flares. Solar activity is expect to increase over the next 24 hours because NOAA AR 2821 flares are estimated to become detectable. C-class flares are likely and there is a small chance of M-class flare activity.

No new Earth-directed Coronal Mass Ejections (CMEs) have been detected in the available coronagraphic imagery.

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 in the past 24 hours, but it might increase because of the Interplanetary Corona Mass Ejection (ICME) arrival detected at 05:49 UT. The 24-hour electron fluence was at nominal levels in the past 24 hours, and might also increase because of the ICME.

The Earth is under the influence of a fast forward shock that arrived at 05:49UT. The solar wind speed increased from 300 to 500 km/s over the past 24 hours. The Bz component of the magnetic field was between 0 and -3 nT before the arrival of the shock and started fluctuating between -20 nT and 20 nT afterward. The interplanetary magnetic field angle had positive values (directed away from the Sun) until 06:35UT and started fluctuating, with mostly negative values. The fast forward shock regime is expected to continue for the next 24 hours.

Geomagnetic conditions were quiet (NOAA Kp 0-2, local K Dourbes 0-1) until the arrival of the fast forward shock. They then increase to a moderate magnetic storm (NOAA K 6) at 12:32 UT. The moderate magnetic storm conditions are expected to remain for the next 24 hours.

Today's estimated international sunspot number (ISN): 031, based on 23 stations.

Solar indices for 11 May 2021

Wolf number Catania	033
10cm solar flux	076
AK Chambon La Forêt	006
AK Wingst	004
Estimated Ap	003
Estimated international sunspot number	030 - Based on 29 stations

Noticeable events summary

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

All times in UTC

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