Viewing archive of Monday, 21 July 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Jul 21 1240 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
21 Jul 2025	145	007
22 Jul 2025	143	010
23 Jul 2025	140	019

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with only C-class flares. The strongest flare was a C6.5 flare (SIDC Flare 4927) peaking at 15:37 UTC on July 20, which was associated with SIDC Sunspot Group 522 (NOAA Active Regions 4136). There are currently ten numbered active regions on the solar disk. SIDC Sunspot Groups 522, 558, 559, 564, 565, 566 (NOAA Active Regions 4136, 4142, 4143, 4149, 4150, 4151) are the most complex ones with magnetic type beta. SIDC Sunspot Group 566 (NOAA Active Region 4151) has emerged in the northwest quadrant. SIDC Sunspot Group 567 (magnetic type alpha) has rotated on disc from the east limb, in the northeast quadrant. SIDC Sunspot Group 562 (NOAA Active Regions 4139) has rotated over the west limb. The solar flaring activity is expected to be moderate over the next 24 hours, with M-class flares very likely and a small chance for X-class flares.

Coronal mass ejections

A prominence eruption was observed in AIA 304 data around 16:30 UTC on July 20, in the east limb. A very narrow associated Coronal Mass Ejection (SIDC CME 527) was observed in LASCO/C2 coronagraph imagery around 17:00 UTC on July 20. It is not expected to impact Earth. No other Earth-directed CMEs were observed in the available coronagraph imagery.

Coronal holes

An elongated, mid-latitude, negative polarity coronal hole (SIDC Coronal Hole 116) continues to cross the central meridian since July 19. An associated high-speed stream may arrive at Earth starting from July 23.

Solar wind

Over the past 24 hours, the solar wind parameters (ACE and DSCOVR) reflected mostly slow solar wind conditions. Speed values ranged between 330 km/s and 440 km/s. The interplanetary magnetic field values were between 3 nT and 7 nT. The Bz component varied between -5 nT and 5 nT. The interplanetary magnetic field angle was mostly in the positive sector. Slow solar wind conditions are expected over the next 24 hours.

Geomagnetism

Geomagnetic conditions globally were mostly at quiet levels (NOAA Kp 1 to 2). Geomagnetic conditions locally were mostly at quiet to unsettled levels (K BEL 1 to 3). Quiet to unsettled conditions are expected for the next 24 hours.

Proton flux levels

The greater than 10 MeV proton flux was below the 10 pfu threshold level 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 18 and GOES 19 was above the 1000 pfu threshold in the last 24 hours. The greater than 2 MeV electron flux is expected to remain above the 1000 pfu threshold the next 24 hours. The 24-hour electron fluence is presently at high levels and is expected to remain so over the next 24 hours.

Today's estimated international sunspot number (ISN): 151, based on 15 stations.

Solar indices for 20 Jul 2025

Wolf number Catania	///
10cm solar flux	150
AK Chambon La Forêt	011
AK Wingst	008
Estimated Ap	006
Estimated international sunspot number	159 - Based on 20 stations

Noticeable events summary

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

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