Viewing archive of Saturday, 9 August 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Aug 09 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Moderate (ISES: Major) magstorm expected (A>=50 or K=6)

Solar protons

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

	10cm flux	Ap
09 Aug 2025	145	035
10 Aug 2025	143	032
11 Aug 2025	141	021

Solar Active Regions and flaring

Solar flaring activity over the last 24 hours has been moderate, with one M-class flare and multiple C-class flares. The strongest flare was an M1.0 flare (SIDC Flare 5080) peaking at 19:10 UTC on August 08, associated with SIDC Sunspot Group 588 (NOAA Active Region 4168, magnetic type beta-gamma). There are currently thirteen numbered active regions on the solar disk. The most complex one is SIDC Sunspot Group 588 (NOAA Active Region 4168, magnetic type beta-gamma). SIDC Sunspot Group 596 (magnetic type beta) has emerged in the northwest quadrant. SIDC Sunspot Groups 555 and 591 (NOAA Active Regions 4161 and 4170, both magnetic type beta) are 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 expected and a small chance for X-class flares.

Coronal mass ejections

A fast Coronal Mass Ejection (SIDC CME 544) was observed in LASCO/C2 and LASCO/C3 coronagraph imagery, starting from around 19:00 UTC on August 08, lifting off the southwest limb. It is most likely associated with a C7.8 flare (SIDC Flare 5079) that peaked at 18:09 UTC on August 08. It is not expected to impact Earth. SIDC CMEs 545, 546, 547, 548 and 549 were observed in LASCO/C2 coronagraph imagery lifting off the east limb during the last 24 hours, associated with eruptive activity near or behind the east limb. They are not expected to impact Earth. SIDC CME was observed in LASCO/C2 coronagraph imagery starting from around 08:50 UTC on August 09, lifting off the southwest limb. It is likely associated with eruptive activity near SIDC Sunspot Group 592 (NOAA Active Region 4173) and it is not expected to impact Earth. No other Earth-directed CMEs were observed in the available coronagraph imagery over the last 24 hours.

Coronal holes

The elongated, southern, positive polarity coronal hole (SIDC Coronal Hole 123) continues to cross the central meridian since August 06. A northern, positive polarity coronal hole (SIDC Coronal Hole 125) is crossing the central meridian. An associated high-speed stream may arrive at Earth starting from the UTC evening on August 11.

Solar wind

The solar wind parameters (ACE) over the last 24 hours were enhanced, under the influence of a high-speed stream from the southern, positive polarity coronal hole (SIDC Coronal Hole 123). The solar wind speed increased from 380 km/s to around 560 km/s and are currently around 480 km/s. The interplanetary magnetic field increased to around 15 nT. The Bz component was mostly negative, reaching values up to -13 nT. The interplanetary magnetic field angle phi was in the positive sector, with a brief period of negative values between 21:00 UTC and 23:50 UTC on August 08. Enhanced solar wind conditions are expected over the next 24-48 hours, under the combined effect of the high-speed stream from SIDC Coronal Hole 123, the expected ICME arrival associated with the Coronal Mass Ejection (SIDC CME 537) that lifted off around 17:15 UTC on August 05 and a second high-speed stream from the northern, positive polarity coronal hole (SIDC Coronal Hole 124).

Geomagnetism

Geomagnetic conditions globally were mostly at minor storm levels (NOAA Kp 5- to 5+) over the last 24 hours. Geomagnetic conditions locally were mostly at active levels (K Bel 4) over the last 24 hours. Mostly minor storm conditions (NOAA Kp 5), with possible moderate storm periods (NOAA Kp 6) are expected over the next 24-48 hours, under the influence of the high-speed stream from the southern, positive polarity coronal hole (SIDC Coronal Hole 123), the expected ICME arrival associated with the Coronal Mass Ejection (SIDC CME 537) that lifted off around 17:15 UTC on August 05 and a second high-speed stream from the northern, positive polarity coronal hole (SIDC Coronal Hole 124).

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.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux measured by GOES and GOES 19 remained below the 1000 pfu threshold during the last 24 hours. The greater than 2 MeV electron flux is expected to remain mostly 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): 166, based on 20 stations.

Solar indices for 08 Aug 2025

Wolf number Catania	163
10cm solar flux	148
AK Chambon La Forêt	046
AK Wingst	022
Estimated Ap	024
Estimated international sunspot number	193 - Based on 29 stations

Noticeable events summary

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

All times in UTC

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