Viewing archive of Saturday, 10 May 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 May 10 1231 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
10 May 2025	137	010
11 May 2025	135	008
12 May 2025	132	005

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. SIDC Sunspot Group 469 (NOAA Active Region [AR] 4079, Beta-Gamma magnetic configuration) was the only flare producing region, with the brightest being SIDC flare 4346, a C3 emitted on 10 May at 01:03 UTC. The solar flaring activity is expected to remain low in the next 24 hours as all visible AR are stable or decreasing in size.

Coronal mass ejections

No Earth-directed Coronal Mass Ejections (CME) were observed in the last 24 hours.

Coronal holes

SIDC Coronal Hole (CH) 101 is a small middle-latitude CH with positive polarity and started crossing the central solar meridian during the past 24 hours. Due to its size, irregular shape, and location it only has a very small chance of affecting Earth. If the effect materialises it will most likely take place on 13 May.

Solar wind

During the past 24 hours the Solar Wind (SW) activity was affected by the expected arrivals of a glancing blow from a Coronal Mass Ejection (CME) and a High Speed Stream (HSS). However the HSS was significantly weakened and had a minor effect to the SW parameters. The SW speed gradually increased from around 400 km/s to 550 km/s, the interplanetary magnetic field (B) varied between 3 and 10 nT, and its North-South component (Bz) fluctuated between -10 and 6 nT. The effects of the CME glancing blow are expected to end in the next hours and the HSS influence is expected to continue at the current level.

Geomagnetism

During the past 24 hours the geomagnetic conditions were affected by the arrivals of a glancing blow from a Coronal Mass Ejection (CME) and a weakened High Speed Stream (HSS). Globally active to unsettled conditions were registered between 9 May 15:00 UTC and 10 May 06:00 UTC (NOAA Kp 3 to 4+) but dropped back to quiet (NOAA Kp 2) since. Locally the conditions were more disturbed, reaching minor storm levels (K BEL 5) from 18:00 to 21:00 UTC on 9 May. However they dropped back to unsettled level (K BEL 3) immediately after this period. As the effects of the CME are now over and the HSS is very weak, the geomagnetic conditions of the next 24 hours are expected to be unsettled to quiet, with possibly brief periods of active conditions.

Proton flux levels

The greater than 10 MeV proton flux, as measured by the GOES-19 satellite, was at nominal levels over the past 24 hours and is likely to remain so in the next 24 hours.

Electron fluxes at geostationary orbit

During the past 24 hours the greater-than 2 MeV electron flux, as measured by GOES 19, reached it peak value of 15000 pfu on 9 May at 16:10 UTC. However it rapidly declined and since 9 May at 21:05 UTC it remains below the 1000 pfu alert level. For the next 24 hours it is expected to continue registering values below the alert threshold. The 24-hour electron fluence was at moderate levels during the past 24 hours and is expected to remain at moderate levels in the next 24 hours.

Today's estimated international sunspot number (ISN): 077, based on 23 stations.

Solar indices for 09 May 2025

Wolf number Catania	093
10cm solar flux	136
AK Chambon La Forêt	026
AK Wingst	022
Estimated Ap	019
Estimated international sunspot number	078 - Based on 28 stations

Noticeable events summary

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

All times in UTC

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