Viewing archive of Tuesday, 5 August 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Aug 05 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
05 Aug 2025	140	008
06 Aug 2025	138	007
07 Aug 2025	136	022

Solar Active Regions and flaring

Solar flaring activity over the last 24 hours has been moderate, with one M-class flare and a few C-class flares. The strongest flare was an M1.1 flare (SIDC Flare 5037) peaking at 02:12 UTC on August 05, associated with SIDC Sunspot Group 588 (NOAA Active Region 4168, magnetic type beta-gamma-delta). There are currently six numbered active regions on the solar disk. The most complex one is SIDC Sunspot Group 588 (NOAA Active Region 4168). SIDC Sunspot Groups 539, 572 and 587 (NOAA Active Regions 4157, 4155 and 4166) have rotated behind the west limb. SIDC Sunspot Group 585 (NOAA Active Region 4167, magnetic type beta) is currently rotating behind the west limb. The solar flaring activity is expected to be moderate to high over the next 24 hours, with M-class flares very likely and a small chance for X-class flares.

Coronal mass ejections

A faint Coronal Mass Ejection (SIDC CME 534) was observed in LASCO/C2 coronagraph imagery around 07:20 UTC on August 04, directed to the northwest. It is likely associated with the M2.0 flare (SIDC flare 5031) that peaked at 04:57 UTC on August 04. Current analysis suggests a chance for the arrival of glancing blow starting from the UTC morning on August 07. A narrow CME (SIDC CME 535) was observed in LASCO/C2 coronagraph imagery around 07:00 UTC on August 05, lifting off the southwest limb. It is associated with eruptive activity near the southwest limb and it is not expected to impact Earth. A second narrow CME (SIDC CME 536) was observed in LASCO/C2 coronagraph imagery around 07:57 UTC on August 05, lifting off the east limb. It is associated with a prominence eruption observed in SUVI 304 data around 07:10 UTC on August 05, in the southeast limb. It is not expected to impact Earth. No other Earth-directed CMEs were observed in the available coronagraph imagery over the last 24 hours.

Solar wind

The solar wind conditions (ACE) were gradually returning to the slow solar wind regime during the past 24 hours, following a period under the influence of the high-speed stream from the equatorial, negative polarity coronal hole (SIDC Coronal Hole 122). The solar wind speed was initially around 480 km/s and then decreased to around 430 km/s. The interplanetary magnetic field decreased from 8 nT to around 5 nT. The Bz component varied between -5 nT and 6 nT. The interplanetary magnetic field angle phi flipped to positive values between 17:00 UTC and 23:45 UTC on August 04, returning then to negative. Slow solar wind conditions are expected over the next 24 hours.

Geomagnetism

Geomagnetic conditions globally were mostly quiet (NOAA Kp 1-2) over the last 24 hours, reaching unsettled levels (NOAA Kp 3) between 00:00 UTC and 06:00 UTC on August 05. Geomagnetic conditions locally were mostly at quiet levels (K Bel 2), with isolated periods of unsettled conditions (K Bel 3). Mostly quiet conditions, with possible isolated unsettled intervals (NOAA Kp 1-3), are expected over the next 24 hours.

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 the threshold level over the next 24 hours, pending no eruptive activity from SIDC Sunspot Group 585 (NOAA Active Region 4167).

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux measured by GOES 18 was over the 1000 pfu threshold between 18:05 UTC and 22:50 UTC on August 04. The greater than 2 MeV electron flux measured by GOES 19 remained below the 1000 pfu threshold during the last 24 hours. The greater than 2 MeV electron flux is expected to below the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence is presently at normal levels and is expected to remain so over the next 24 hours.

Today's estimated international sunspot number (ISN): 113, based on 22 stations.

Solar indices for 04 Aug 2025

Wolf number Catania	105
10cm solar flux	142
AK Chambon La Forêt	017
AK Wingst	012
Estimated Ap	009
Estimated international sunspot number	108 - 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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