Viewing archive of Friday, 1 August 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Aug 01 1241 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
01 Aug 2025	143	009
02 Aug 2025	141	006
03 Aug 2025	145	004

Solar Active Regions and flaring

Solar flaring activity was at low levels with low C-class flaring over the past 24 hours. A total of 10 numbered sunspot groups were identified on the visible solar disk, all of them being magnetically simple, classified as magnetic type beta or alpha. The most notable activity was a C2.4 flare (SIDC Flare 4984) with peak time 03:39 UTC on Aug 01, produced by SIDC Sunspot Group 564 (NOAA Active Region 4149) from near the west limb. The newly numbered SIDC Sunspot Group 585 (NOAA Active Region 4167), classified as magnetic type beta, has exhibited significant flux emergence and growth over the past 24 hours, contributing to much of the on-disc flaring activity. Other notable regions which contributed to the C-class flaring are SIDC Sunspot Group 572 (NOAA Active Region 4155) and SIDC Sunspot Group 570 (NOAA Active Region 4153). Both have exhibited further decay. The solar flaring activity is expected to be at low to moderate levels over the next 24 hours, with expected background C-class flaring and 50% chances for M-class flares mostly related to region SIDC Sunspot Group 585.

Coronal mass ejections

No other Earth-directed coronal mass ejection (CMEs) have been detected in the available coronagraph imagery over the past 24 hours.

Coronal holes

A long narrow negative-polarity coronal hole (SIDC 122), stretching between equatorial region and mid-north latitudes, is currently crossing the central meridian. A mild high-speed stream related to it might reach the Earth on Aug 04.

Solar wind

Over the past hours the solar wind parameters as measured by ACE have reflected a mild connection to a high-speed stream from a negative polarity coronal hole. The total interplanetary magnetic field (B) reached a maximum of 9.2 nT with a minimum north-south component, Bz, of -6.8 nT. The solar wind speed varied between 376 km/s and 557 km/s. The B field phi angle remained predominantly in the negative sector (directed towards the Sun). Slightly enhanced solar wind conditions are expected to continue over the next day with a smooth transition towards nominal slow solar wind conditions by the end of Aug 02. Mostly nominal solar wind conditions are expected thereafter until a new possible mild high speed stream arrival on Aug 04.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet to unsettled. Predominantly quiet to unsettled geomagnetic conditions are expected for the next 24 hours with remaining small chances for isolated active periods. Mostly quiet conditions are expected thereafter with next possible active periods on Aug 04.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux has been at nominal levels and is expected to remain so over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV GOES electron flux has exceeded the 1000 pfu threshold over the past 24 hours and is expected to exceed the threshold again in the next 24 hours. The 24-hour electron fluence was at nominal levels and is expected to remain so in the next 24 hours.

Today's estimated international sunspot number (ISN): 137, based on 15 stations.

Solar indices for 31 Jul 2025

Wolf number Catania	167
10cm solar flux	145
AK Chambon La Forêt	017
AK Wingst	013
Estimated Ap	012
Estimated international sunspot number	145 - Based on 32 stations

Noticeable events summary

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

All times in UTC

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