Viewing archive of Monday, 24 May 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 May 24 1326 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

	10cm flux	Ap
24 May 2021	076	003
25 May 2021	076	034
26 May 2021	076	027

Bulletin

Gamma-beta region NOAA 2824 has produced several B flares and one C2.2 flare (peaking at 17:05 UT on May 23) in the past 24 hours. The C2.2 flare and the B4.8 flare peaking at 00:34 UT on May 24 were accompanied by a dimming. The chance for a C flare in the next 24 hours is estimated at 75%, while the chance for an M flare is estimated at 25%.

A CME was observed in COR2 A imagery at 11:00 UT on May 23, with estimated speed of 680 km/s, and is expected to arrive at Earth around 3h UT on May 26. A second CME, probably associated with the C2.2 flare, was observed in LASCO C2 at 17:48 UT on May 23. It has an estimated speed of 690 km/s and expected arrival time around 10h UT on May 26. A third CME, probably associated with the B4.8 flare peaking at 00:34 UT on May 24, was observed in LASCO C2 at 01:25 UT. This CME is probably Earthbound, but the available imagery did not allow to calculate its speed yet.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours. The greater than 2 MeV electron flux was a bit below threshold value levels in the past 24 hours, and is expected to gradually decrease in the next 24 hours. The greater than 2 MeV electron fluence was a bit below moderate threshold value levels during the past 24 hours, and is expected to gradually decrease in the next 24 hours.

Solar wind speed near Earth as registered by DSCOVR varied between about 325 and 420 km/s in the past 24 hours, with current values around 360 km/s. The Interplanetary Magnetic Field (IMF) was oriented towards the Sun and its magnitude varied between 2 and 4 nT. Solar wind speeds are expected to increase in the second half of May 25, with the arrival of several CMEs on May 25 and May 26.

Quiet geomagnetic conditions (K Dourbes between 1 and 2; NOAA Kp between 1 and 2) were registered in the past 24 hours. Quiet levels (K Dourbes < 3) are expected on May 24 and the first half of May 25. Minor storm intervals (K Dourbes = 5) are possible in the second half of May 25 and on May 26, with a chance for moderate geomagnetic levels (K Dourbes = 6), due to the expected arrival of several CMEs.

Today's estimated international sunspot number (ISN): 028, based on 14 stations.

Solar indices for 23 May 2021

Wolf number Catania	///
10cm solar flux	079
AK Chambon La Forêt	008
AK Wingst	004
Estimated Ap	004
Estimated international sunspot number	026 - Based on 26 stations

Noticeable events summary

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

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