Viewing archive of Sunday, 23 April 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Apr 23 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Major (ISES: Severe) magstorm expected (A>=100 or K>=7)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
23 Apr 2023	140	030
24 Apr 2023	140	082
25 Apr 2023	140	021

Bulletin

Solar flaring activity at low levels over the past 24 hours with only isolated low C-class flaring. There are six numbered active regions on the visible solar disc. The largest and most complex one, NOAA AR 3282 (beta-gamma), has remained stable and inactive. The strongest activity was a C2.2 flare, peak time 06:40 UTC on April 23rd, produced by NOAA AR 3279 (beta). The rest of the active regions, including a newly formed unnumbered region rear NOAA AR 3285 (beta), have been stable and inactive. The solar flaring activity is expected to be at low levels over the next 24 hours with low chances for isolated M-class flaring.

No Earth-directed coronal mass ejections (CMEs) have been detected in the available coronagraph imagery over the past 24 hours. The halo CME related to M-class flaring and filament eruption on April 21st is expected to arrive to Earth over the next 24 hours.

Over the past 24 hours the greater than 10 MeV GOES proton flux was elevated, remaining well below radiation storm levels. The greater than 10 MeV GOES proton flux is expected to remain enhanced over the next 24 hours with the chances of reaching minor radiation storm levels. The greater than 2 MeV electron flux has been below the 1000 pfu threshold and is expected to remain so. The 24h electron fluence was at nominal levels and is expected to remain so over the next 24 hours.

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) were mainly at background slow solar wind levels until around 08:00 UTC on April 23rd when the beginning of an ongoing disturbance was first observed. It is too early to determine the nature of this disturbance, but it could be a precursor of the expected ICME arrival. The solar wind velocity varied from 329 km/s to 457 km/s. The interplanetary magnetic field reached a maximum value of 11.8 nT and a minimum Bz of -11.7 nT. The B field was mostly in the negative sector with some switch backs to the positive sector (directed away from the Sun). The solar wind conditions are expected to be significantly perturbed over the next 24 hours with an anticipated strong ICME arrival, related to the CME driven by M-flaring and filament eruption on April 21st.

The geomagnetic conditions over the past 24 hours were globally quiet and locally quiet to unsettled over Belgium. The geomagnetic conditions are expected to be significantly elevated over the next 24 hours with expected moderate to major geomagnetic storms and chances for severe storm levels due to an expected ICME arrival.

Today's estimated international sunspot number (ISN): 093, based on 09 stations.

Solar indices for 22 Apr 2023

Wolf number Catania	///
10cm solar flux	141
AK Chambon La Forêt	012
AK Wingst	///
Estimated Ap	008
Estimated international sunspot number	108 - Based on 21 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page