Viewing archive of Sunday, 21 May 2023

Solar activity report

Report of Solar-Geophysical Activity 2023 May 21 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 141 Issued at 2200Z on 21 May 2023

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

Solar activity has been at high levels for the past 24 hours. The largest solar event of the period was a M5 event observed at 20/2306Z from Region 3311 (N18E47). There are currently 8 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be moderate with a chance for X-class flares on days one, two, and three (22 May, 23 May, 24 May).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field has been at quiet to major storm levels for the past 24 hours. Solar wind speed reached a peak of 632 km/s at 20/2216Z. Total IMF reached 13 nT at 21/1516Z. The maximum southward component of Bz reached -10 nT at 21/1935Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 1084 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to major storm levels on day one (22 May), quiet to minor storm levels on day two (23 May) and unsettled to minor storm levels on day three (24 May). Protons have a slight chance of crossing threshold on days one, two, and three (22 May, 23 May, 24 May).
III. Event Probabilities 22 May to 24 May
Class M75%75%75%
Class X30%30%30%
IV. Penticton 10.7 cm Flux
  Observed       21 May 163
  Predicted   22 May-24 May 160/155/150
  90 Day Mean        21 May 153

V. Geomagnetic A Indices
  Observed Afr/Ap 20 May  026/030
  Estimated     Afr/Ap 21 May  013/021
  Predicted    Afr/Ap 22 May-24 May  016/022-014/018-020/022

VI. Geomagnetic Activity Probabilities 22 May to 24 May
A. Middle Latitudes
Minor storm35%20%30%
Major-severe storm20%05%15%
B. High Latitudes
Minor storm25%20%25%
Major-severe storm60%20%50%

All times in UTC

<< Go to daily overview page

Latest news


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!

Support SpaceWeatherLive with our merchandise
Check out our merchandise

Latest alerts

Get instant alerts!

Space weather facts

Last X-flare2024/05/15X2.9
Last M-flare2024/05/24M1.4
Last geomagnetic storm2024/05/17Kp6 (G2)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
April 2024136.5 +31.6
May 2024150.5 +14
Last 30 days144.3 +8.4

This day in history*

Solar flares
*since 1994

Social networks