Viewing archive of Saturday, 22 May 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 May 22 1230 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
22 May 2021	074	007
23 May 2021	076	007
24 May 2021	078	007

Bulletin

NOAA AR 2824 (Catania 96, alpha magnetic field configuration) has produced 6 C-class flares in the past 24 hours, the strongest being a C6.1 peaking at 02:56 UT. More C-class flares are highly likely, and M-class flares are possible.

There could be a CME partially directed towards the Earth, associated with the C-class flaring activity mentioned above (around 08:00 UT), there is not enough coronagraph data yet to do a better assessment, more information will be given as the data becomes available.

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 barely below the 1000 pfu in the past 24 hours, it is expected to decrease in the coming 24 hours. The 24-hour electron fluence was at normal levels in the past 24 hours, but close to the moderate limit, it may reach this level before decreasing in the coming 24 hours.

The effect of the high speed solar wind (HSS) stream at Earth is vanishing. The speed is around 440 km/s, with interplanetary magnetic field magnitudes of 3 nT. The polarity of the magnetic field was mostly negative (towards the Sun). A further decrease in solar wind speed is expected for the next 24 hours.

Geomagnetic conditions have been quiet (KDourbes 1-2, Kp 1-2), similar conditions can be expected for the next 24 hours.

Today's estimated international sunspot number (ISN): 015, based on 10 stations.

Solar indices for 21 May 2021

Wolf number Catania	015
10cm solar flux	074
AK Chambon La Forêt	011
AK Wingst	008
Estimated Ap	008
Estimated international sunspot number	013 - Based on 25 stations

Noticeable events summary

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

All times in UTC

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