Viewing archive of Thursday, 19 March 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Mar 19 1237 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
19 Mar 2026	115	022
20 Mar 2026	117	044
21 Mar 2026	118	037

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours. The largest flare was a C3.6 flare (SIDC Flare 7229) peaking on March 18 at 13:11 UTC, which was produced by SIDC Sunspot Group 820 (NOAA Active Region 4392). This region is the largest on disk but has decreased in complexity and has now Beta magnetic configuration. There are currently 3 numbered regions on the disk. SIDC Sunspot Group 825 (NOAA Active Region 4397) rotated on disk and was numbered over the period. SIDC Sunspot Groups 818, 822 and 824 decayed to plage regions. Solar flaring activity is expected to be low over the next 24 hours, with C-class flares expected and further isolated M-class flares possible.

Coronal mass ejections

The CME reported yesterday, observed in STEREO A COR2 at 09:23 UTC on March 18 and to the west in SOHO/LASCO-C2 data from 09:24 UTC on March 18, is expected to arrive at Earth late on March 20 to early on March 21. 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) began to transit the central meridian on March 19.

Solar wind

Over the past 24 hours, the solar wind parameters reflected slow solar wind conditions. The solar wind speed ranged between 350 and 450 km/s. The total magnetic field was stable around 5 nT. Bz had a minimum of -4 nT. The interplanetary magnetic field phi angle was mostly in the positive sector (directed towards the Sun. Enhanced solar wind conditions are expected from late on March 19 due to an anticipated CME arrival (SIDC CME 639) combined with a possible sector boundary crossing.

Geomagnetism

Over the past 24 hours, the geomagnetic conditions were at quiet levels globally and locally (NOAA KP 2 and K BEL 2). Minor to moderate storm conditions are possible from late on March 19 due to the possible ICME arrival and influence from the sector boundary crossing.

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 2949 pfu. The greater than 2 MeV electron flux is expected to again exceed the 1000 pfu threshold over the next 24 hours. The electron fluence was at moderate levels and is expected to be at moderate levels for the next 24 hours.

Today's estimated international sunspot number (ISN): 036, based on 25 stations.

Solar indices for 18 Mar 2026

Wolf number Catania	///
10cm solar flux	113
AK Chambon La Forêt	009
AK Wingst	006
Estimated Ap	004
Estimated international sunspot number	068 - Based on 30 stations

Noticeable events summary

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

All times in UTC

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