Viewing archive of Friday, 20 March 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Mar 20 1241 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Moderate (ISES: Major) magstorm expected (A>=50 or K=6)

Solar protons

Quiet

	10cm flux	Ap
20 Mar 2026	105	035
21 Mar 2026	104	039
22 Mar 2026	104	035

Solar Active Regions and flaring

Solar flaring activity was very low over the past 24 hours. The X-ray flux was below C level. There are currently 2 numbered regions on the disk: SIDC Sunspot Group 820 (NOAA Active Region 4392 magnetic type beta) and SIDC Sunspot Group 825 (NOAA Active Region 4397) both of these regions were stable over the period. SIDC Sunspot Group 819 (NOAA active region 4393) decayed to a plage region. Solar flaring activity is expected to be low over the next 24 hours, with C-class flares expected

Coronal mass ejections

No new Earth directed CMEs were detected in the available coronagraph imagery.

Coronal holes

The southern midlatitude extension of the large positive polarity coronal hole (SIDC Coronal Hole 154) continues to cross the central meridian. The extended negative polarity equatorial coronal hole (SIDC Coronal Hole 147) also continues to transit the central meridian.

Solar wind

Over the past 24 hours, the solar wind parameters reflected slow solar wind conditions until around 01:30 UTC on March 20 when the magnetic field and solar wind speed began to increase, indicating the arrival of an ICME. The solar wind speed increased from around 330 km/s to 470 km/s. The total magnetic field increased from 5 nT to a maximum of 19nT at 11:40 UTC March 20. Bz had a minimum value of -11 nT at 04:45 UTC but was predominantly positive. The interplanetary magnetic field phi angle was mostly in the positive sector (directed towards the Sun). Continued enhanced solar wind conditions are expected on March 20 due to the ongoing ICME influence. From late on March 20 and March 21 the solar wind conditions are expected to become further enhanced due to two further predicted CME arrivals from March 17 and 18, combined with a possible sector boundary crossing and high speed stream arrival.

Geomagnetism

Over the past 24 hours, the geomagnetic conditions were at quiet levels on March 19. Om March 20 between 06:00 and 12:00 UTC Active conditions were reached (NOAA KP 4- and K BEL 4), in response to the ICME arrival. Minor to moderate storm conditions are expected March 20 due to the ongoing ICME influence in addition to the further CME arrivals and influence from the sector boundary crossing, with a slight chance for major storm conditions due to these combined effects.

Proton flux levels

The greater than 10 MeV proton flux was below the 10 pfu threshold over the past 24 hours. It is expected to remain below this threshold level 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 satellites, exceeded the 1000 pfu threshold and reached a maximum of 4941 pfu. From 05:00 UTC March 20 the flux returned below the threshold. The greater than 2 MeV electron flux is expected to remain below the 1000 pfu threshold over the next 24 hours. The electron fluence was at moderate levels and is expected to be at low to moderate levels for the next 24 hours.

Today's estimated international sunspot number (ISN): 031, based on 17 stations.

Solar indices for 19 Mar 2026

Wolf number Catania	///
10cm solar flux	106
AK Chambon La Forêt	005
AK Wingst	002
Estimated Ap	002
Estimated international sunspot number	036 - Based on 33 stations

Noticeable events summary

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

All times in UTC

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