Viewing archive of Saturday, 1 November 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Nov 01 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
01 Nov 2025	125	016
02 Nov 2025	125	013
03 Nov 2025	125	014

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. A total of 3 numbered sunspot groups were identified on the disk over the past 24 hours. The largest flare was a C7.1 flare (SIDC Flare 5887) peaking on October 31 at 20:43 UTC, from a region rotating into view over the east limb. This region has been producing important flares and CMEs in the last days, so we expect solar activity to increase due to it, C-class flares can be expected and M-class flares are likely.

Coronal mass ejections

A wide CME erupted towards the east first seen by LASCO C2 at 08:48 UTC on 31 October. This CME was followed by a second one at 20:12 UTC towards the NE. Both CMEs were backsided and will not arrive to the Earth.

Coronal holes

There are three positive polarity CHs in the western hemisphere. SIDC Coronal Hole 123 is the largest, located in the south. SIDC Coronal Hole 128 is smaller and located at the equator. Finally, SIDC Coronal Hole 129 has a considerable size and is located in the northern hemisphere.

Solar wind

The solar wind speed has decreased to about 500 km/s, under the waning influence of the HSS from SIDC Coronal Hole 123, the interplanetary magnetic field is around 6 nT. We expect a gradual return to slow solar wind in the next 24 hours. Nevertheless, we may see instead the arrival of the high speed solar wind from SIDC Coronal Hole 129, located in the northern hemisphere (also positive polarity). This coronal hole is located above 20 degrees latitude, meaning that its HSS may miss the Earth. There is also a possible arrival, in the next 24 hours of the CME from 28 October (SIDC CME 589), but this will be a weak event.

Geomagnetism

Geomagnetic conditions reached active levels (Kp and K_Bel up to 4). In the next 24 hours, active to minor storm conditions can be expected if the HSS from SIDC Coronal Hole 129 and the CME from 28 October (SIDC CME 589) arrive.

Proton flux levels

The greater than 10 MeV GOES proton flux 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 measured by GOES 18 and GOES 19 was above the 1000 pfu threshold after 12:00 UTC on 31 October. The greater than 2 MeV electron flux is expected to remain above the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence was at normal levels, but increasing, it is expected to reach moderate levels over the next 24 hours.

Today's estimated international sunspot number (ISN): 023, based on 06 stations.

Solar indices for 31 Oct 2025

Wolf number Catania	033
10cm solar flux	125
AK Chambon La Forêt	025
AK Wingst	028
Estimated Ap	026
Estimated international sunspot number	044 - Based on 22 stations

Noticeable events summary

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

All times in UTC

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