Viewing archive of Tuesday, 25 April 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 Apr 25 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
25 Apr 2023	132	005
26 Apr 2023	130	002
27 Apr 2023	128	004

Bulletin

Solar flaring activity was low, with seven C-class flares detected during the last 24 hours. Three of those flares were emitted from NOAA Active Region (AR) 3283 (magnetic configuration Beta, Catania group 59) including the brightest, a C2 flare that peaked yesterday 13:05 UT. Two C1 flares were detected today from an AR at N20 currently rotating to Earth's view. A newly-emerged flux has appear SE of NOAA AR 3285 (magnetic configuration Beta, Catania group 65). More C-class flaring activity is expected, particularly from the AR region at N20E90 and the NOAA AR 3285 area.

A Coronal Mass Ejection (CME) detected automatically by CACTus yesterday 14:12 UT is directed southwards but has a chance of delivering a glancing blow at 27 or 28 Apr. A second CME also detected by CACTus yesterday 03:48 UT is not expected to be geo-effective as it is directed eastwards.

The greater than 10 MeV proton flux was at nominal levels over the past 24 hours and is expected to remain so for the next 24 hours. The greater than 2 MeV electron flux remained below the 1000 pfu alert threshold and is expected to remain below this threshold during the next 24 hours. The 24h electron fluence was at nominal levels and is expected to remain so.

The Solar Wind (SW) conditions are returning to a slow SW regime for the last 24 hours. The SW speed ranged between 490 and 600 km/s in the last 24 hours. The total interplanetary magnetic field (Bt) dropped steadily from 32 to 5 nT and its North-South component (Bz) followed the same trend in absolute value and now ranges between -5 and 5 nT. The interplanetary magnetic field phi angle was predominantly directed towards the Sun until today 03:00 UT and has now turned away from the Sun. The SW conditions will continue their return to a slow SW regime in the next 24 hours.

Geomagnetic conditions dropped from moderate to quiet globally (Kp 4- to 1+) and from active to quiet locally (K BEL 4 to 1) during the past 24 hours. Quiet conditions are expected to prevail in the next 24 hours, both globally and locally.

Today's estimated international sunspot number (ISN): 086, based on 18 stations.

Solar indices for 24 Apr 2023

Wolf number Catania	///
10cm solar flux	134
AK Chambon La Forêt	033
AK Wingst	///
Estimated Ap	061
Estimated international sunspot number	079 - Based on 17 stations

Noticeable events summary

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

All times in UTC

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