Viewing archive of Thursday, 16 April 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Apr 16 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
16 Apr 2026	099	007
17 Apr 2026	099	007
18 Apr 2026	099	028

Solar Active Regions and flaring

A total of 3 numbered sunspot groups were identified on the disk over the past 24 hours. Solar flaring activity was low over the past 24 hours, with only C-class flares identified. The largest flare was a C1.2 flare (SIDC Flare 7408) peaking on April 16 at 00:53 UTC, which was produced by SIDC Sunspot Group 825 (NOAA Active Regions 4397, 4419). Solar flaring activity is expected to be low over the next 24 hours, with C-class flares likely.

Coronal mass ejections

A filament located around S20E20 erupted early on 15 April, leading to a CME seen by LASCO C2 at 09:00 UT on 15 April. This CME is mostly directed to the south and most likely will not arrive to the Earth, but there are low chances of seeing a glancing blow on 18-19 August.

Coronal holes

There's a large equatorial coronal hole located in the northern hemisphere (SIDC Coronal Hole 147).

Solar wind

The solar wind speed is low, around 330 km/s with interplanetary magnetic field magnitude of 5 nT, with positive polarity (away from the Sun). The high speed solar wind stream from a large coronal hole located in the northern hemisphere (SIDC Coronal Hole 147) will reach the Earth in 24 to 48h.

Geomagnetism

Geomagnetic conditions have been quiet to unsettled (Kp up to 2 and K_BEL up to 3). Similar conditions can be expected for the next 24 hours.

Proton flux levels

The greater than 10 MeV proton flux, as measured by GOES-18, was below the 10 pfu threshold level over the past 24 hours and is expected to remain so for the next 24 hours.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by GOES-18 and GOES-19 went 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 24-hour electron fluence was at normal to moderate levels over the past 24 hours and is expected to remain at these levels over the next 24 hours.

Today's estimated international sunspot number (ISN): 054, based on 18 stations.

Solar indices for 15 Apr 2026

Wolf number Catania	///
10cm solar flux	105
AK Chambon La Forêt	009
AK Wingst	008
Estimated Ap	005
Estimated international sunspot number	052 - Based on 21 stations

Noticeable events summary

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

All times in UTC

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