Visualizzazione archivio di martedì, 21 aprile AM

Daily bulletin on solar and geomagnetic activity from the SIDC

Emesso: 2026 Apr 21 1231 UTC

SIDC Forecast

Brillamenti solari

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Protoni solari

Quiet

	10cm flux	Ap
21 Apr 2026	109	016
22 Apr 2026	114	020
23 Apr 2026	120	010

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. A total of 4 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 very likely and a chance for M-class flares.

Espulsioni di massa coronale

No Earth directed Coronal Mass Ejections (CMEs) were observed in the past 24 hours. Further analysis of the CME seen LASCO-C2 data around 16:00 UTC on April 19 show that it is not expected to impact the Earth.

Fori coronali

SIDC Coronal Hole 157 (equatorial coronal hole extending to the polar-south with a positive polarity) has started crossing the central meridian on April 21. (Other crossing times : April 04)

Vento solare

Over the past 24 hours the solar wind parameters were under the influence of a high-speed stream associated with SIDC Coronal Hole 147. The solar wind speed ranged between 444 km/s to 573 km /s. The total interplanetary magnetic field ranged from 4 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 minor storm conditions globally and locally (Kp 5 & K BEL 5) in the last 24 hours. Active to minor storm 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 was above the 1000 pfu alert threshold between 16:55 UTC and 23:45 UTC on April 20, in the past 24 hours. The flux as measured by GOES-18 and GOES-19 is expected to fluctuate around the alert threshold over the next 24 hours. The 24-hour electron fluence was at normal 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): 053, based on 23 stations.

Solar indices for 20 Apr 2026

Wolf number Catania	044
10cm solar flux	105
AK Chambon La Forêt	041
AK Wingst	030
Estimated Ap	028
Estimated international sunspot number	042 - Based on 32 stations

Noticeable events summary

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

Tutti gli orari in UTC

<< Vai alla pagina della panoramica giornaliera