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

Valid from 1230 UTC, 22 May 2021 until 24 May 2021
Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

10cm fluxAp
22 May 2021074007
23 May 2021076007
24 May 2021078007

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 Catania015
10cm solar flux074
AK Chambon La Forêt011
AK Wingst008
Estimated Ap008
Estimated international sunspot number013 - Based on 25 stations

Noticeable events summary

DayBeginMaxEndLocStrengthOP10cmCatania/NOAARadio burst types
None

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

All times in UTC

<< Go to daily overview page

Latest news

Support SpaceWeatherLive.com!

A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!

Donate SpaceWeatherLive Pro
Support SpaceWeatherLive with our merchandise
Check out our merchandise

Latest alerts

Get instant alerts!

Space weather facts

Last X-flare2025/03/28X1.1
Last M-flare2025/04/01M2.4
Last geomagnetic storm2025/03/27Kp5 (G1)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
February 2025154.6 +17.6
April 2025147 -7.6
Last 30 days128.8 -21.8

This day in history*

Solar flares
12001X28.5
22001X2.01
32001X1.59
42014M9.35
52017M8.22
DstG
11960-272G3
21973-173G3
32001-101G1
41976-101G1
51994-96G3
*since 1994

Social networks