Viewing archive of Monday, 20 April 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Apr 20 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
20 Apr 2026	103	010
21 Apr 2026	099	013
22 Apr 2026	095	007

Solar Active Regions and flaring

Solar flaring activity was very low over the past 24 hours. The X-ray flux was below C level. A total of 2 numbered sunspot groups were identified on the disk over the past 24 hours. SIDC Sunspot Group 825 (NOAA Active Region 4419) is the largest and most magnetically complex (Beta-Gamma) regions on disk. Solar flaring activity is expected to be low over the next 24 hours, with C-class flares likely and a small chance for M-class flares.

Coronal mass ejections

A Coronal Mass Ejection (CME) was observed erupting towards the north-east, in LASCO-C2 data around 16:00 UTC on April 19. This CME is associated with a filament eruption seen in SDO/AIA 304 in around 15:15 UTC on April 19, with an estimated speed of 378 km/s. Analysis of this CME is ongoing.

Solar wind

Over the past 24 hours the solar wind parameters were under the waning influence of a high-speed stream associated with SIDC Coronal Hole 147. The solar wind speed ranged between 406 km/s to 522 km /s. The total interplanetary magnetic field ranged from 2 to 10 nT, with the Bz reaching a minimum of -8 nT. The phi-angle was mainly in the negative sector (directed towards the Sun), with periods in the positive sector. In the next 24 hours solar wind conditions are expected to remain enhanced.

Geomagnetism

The geomagnetic conditions reached active condition globally (Kp 4) and unsettled conditions locally (K BEL 3) in the last 24 hours. Active conditions are expected over the next 24 hours.

Proton flux levels

The greater than 10 MeV GOES proton flux was at background levels and is expected to remain at background levels over the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by GOES-18 and GOES-19 was above the 1000 pfu alert threshold in the past 24 hours. The flux is expected to fluctuate around the alert threshold over the next 24 hours. The greater than 2 MeV electron flux, as measured by GOES-18 and GOES-19 was above the 1000 pfu alert threshold in the past 24 hours. The flux is expected to fluctuate around the alert threshold over the next 24 hours.

Today's estimated international sunspot number (ISN): 042, based on 27 stations.

Solar indices for 19 Apr 2026

Wolf number Catania	///
10cm solar flux	105
AK Chambon La Forêt	019
AK Wingst	018
Estimated Ap	019
Estimated international sunspot number	040 - Based on 25 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