Viewing archive of Sunday, 6 April 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Apr 06 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
06 Apr 2025	179	031
07 Apr 2025	177	017
08 Apr 2025	175	024

Solar Active Regions and flaring

Solar flaring activity was moderate, with one M-class flare recorded over the past 24 hours. The largest flare was an M1.0 flare (SIDC Flare 4035), peaking at 20:05 UTC on April 5, associated with SIDC Sunspot Group 461 (NOAA Active Region 4048; beta-gamma). There are currently ten numbered active regions visible on the solar disk. SIDC Sunspot Group 461 (NOAA Active Region 4048; beta-gamma), which remains the largest and most magnetically complex region on the disk, was the main driver of the flaring activity observed over the past 24 hours. Low flaring activity was also produced by SIDC Sunspot Group 455 (NOAA Active Region 4043; beta), which has now rotated over the west limb. SIDC Sunspot Group 456 (NOAA Active Region 4044; beta) and SIDC Sunspot Group 465 (NOAA Active Region 4051; beta) are now approaching the west limb. Other regions on the disk have simple photospheric magnetic field configurations (alpha and beta) and did not show any significant flaring activity. Solar flaring activity is expected to be at moderate levels over the next 24 hours, with M-class flares likely and a small chance for X-class flares.

Coronal mass ejections

No Earth-directed Coronal Mass Ejections (CMEs) have been detected in the available coronagraph images.

Solar wind

Over the past 24 hours, solar wind parameters were slightly disturbed under the mild influence of a high-speed stream (HSS) from a negative polarity coronal hole. The interplanetary magnetic field reached values of up to 9 nT, and the solar wind speed ranged between 600 and 700 km/s. The southward component of the interplanetary magnetic field fluctuated between –7 nT and 7 nT. The magnetic field orientation was predominantly in the negative sector (field directed toward the Sun). Solar wind conditions are expected to remain slightly elevated over the next day, before gradually returning to slow solar wind conditions. From late on April 7, solar wind parameters may become slightly elevated again due to the possible arrival of a high-speed stream from a negative polarity coronal hole (SIDC Coronal Hole 99), which began crossing the central meridian on April 4.

Geomagnetism

Geomagnetic conditions over the past 24 hours reached minor storm levels both globally and locally over Belgium (NOAA Kp: 5+; K-Bel: 5). Mostly unsettled to active conditions are expected over the next day due to the ongoing influence of a high-speed stream. From April 8, active conditions are expected, with a possible isolated minor storm interval in response to the arrival of the high-speed stream from a negative polarity coronal hole (SIDC Coronal Hole 99).

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux was slightly elevated, remaining well below radiation storm levels. The proton flux is expected to gradually return to nominal levels over the next day, with a small chance of exceeding minor storm levels if any high-energy flares or eruptions occur.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by GOES-16 and GOES-18, exceeded the 1000 pfu threshold over the past 24 hours. The greater than 2 MeV electron flux is expected to exceed this threshold again in the coming days. The 24-hour electron fluence was at normal to moderate levels and is expected to remain at moderate levels over the next 24 hours.

Today's estimated international sunspot number (ISN): 175, based on 21 stations.

Solar indices for 05 Apr 2025

Wolf number Catania	///
10cm solar flux	184
AK Chambon La Forêt	041
AK Wingst	039
Estimated Ap	039
Estimated international sunspot number	174 - Based on 21 stations

Noticeable events summary

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

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