Viewing archive of Wednesday, 4 February 2026

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2026 Feb 04 1231 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
04 Feb 2026	178	007
05 Feb 2026	180	013
06 Feb 2026	180	029

Solar Active Regions and flaring

A total of 9 numbered sunspot groups were identified on the disk over the past 24 hours. There was one X-class flare and numerous M-class flares in the past 24 hours. All the major solar activity originates at SIDC Sunspot Group 784 (NOAA Active Region 4366) currently located at N13E07, with a Beta-Gamma-Delta magnetic configuration and growing over the past 24 hours. The largest flare was a X1.5 flare (SIDC Flare 6857) peaking on February 03 at 14:08 UTC. Solar flaring activity is expected to be high over the next 24 hours, with M-class flares very likely and X-class flares possible.

Note: there is an X-flare ongoing at the time this bulletin is been sent, it will be reported in a separated PRESTO and in tomorrow's ursigram.

Coronal mass ejections

No Earth directed CMEs have been detected in the last 24 hours.

Solar wind

The solar wind speed at Earth is currently low, around 330 km/s. A sector boundary crossing was observed on February 3 at 18:30 UTC, during which the interplanetary magnetic field (IMF) orientation changed from toward to away from the Sun. Slightly disturbed solar wind conditions began at 08:00 UTC on February 4, likely caused by a minor ICME glancing blow corresponding to a CME from 30–31 January. Currently, the IMF is about 12 nT, with Bz at –3 nT. Over the next 24 hours, we expect the arrival of the ICME associated with the CME from February 2 (linked to the X8.1 flare). This ICME already passed Solar Orbiter, as measured by the MAG and SWA instruments, at 17:00 UTC on February 3, which may indicate a slightly earlier arrival at Earth —by a few hours— than the previous forecast of 06:00 UTC on February 5. Nevertheless, the actual arrival time may not shift significantly, since the ICME is propagating into very low solar wind speeds, close to 300 km/s.

Geomagnetism

Geomagnetic conditions have been quiet in the last 24 hours (Kp and K_BEL up to 2). Moderate storm levels (K up to 6) can be expected with the ICME (from the 2 February CME) arrival on 5 February.

Proton flux levels

The greater than 10 MeV proton flux remained below the 10 pfu threshold in the last 24 hours. SIDC Sunspot Group 784 (NOAA Active Region 4366) is crossing the central meridian, becoming better magnetically connected with the Earth and increasing the risk of a proton storm.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux as measured by GOES 18 and GOES 19 has been mostly above the 1000 pfu threshold for most of the last 24 hours. Similar conditions can be expected for the next 24 hours. The 24-hour electron fluence was at moderate levels and is expected to remain so.

Today's estimated international sunspot number (ISN): 154, based on 09 stations.

Solar indices for 03 Feb 2026

Wolf number Catania	223
10cm solar flux	178
AK Chambon La Forêt	006
AK Wingst	007
Estimated Ap	005
Estimated international sunspot number	165 - Based on 11 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