Viewing archive of Thursday, 25 April 2024

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2024 Apr 25 1248 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

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

	10cm flux	Ap
25 Apr 2024	204	007
26 Apr 2024	204	013
27 Apr 2024	204	011

Solar Active Regions and flaring

Solar flaring activity remained at high levels in the past 24 hours with multiple low M-class flares. There are 16 numbered and several unnumbered active regions on the visible solar disc. NOAA AR 3645 (beta-gamma) remains the largest region, while NOAA AR 3643 (beta-gamma-delta) and NOAA AR 3648 (beta-gamma-delta) became the most complex ones. NOAA AR 3639 (beta), NOAA AR 3646 (beta) and NOAA AR 3647 (beta) have decreased the complexity of their underlying magnetic field. The strongest activity was M2.0 flare, start time 22:54 UTC, end time 23:05 UTC, peak time 22:59 UTC on April 24th produced by NOAA AR 3637 (beta) from the west limb. The remaining M-class flaring was produced by NOAA AR 3645 and NOAA AR 3648. The solar flaring activity is expected to be at moderate to high levels over the next days with likely further M-class flaring and 25% chance for isolated X-class flaring.

Coronal mass ejections

No Earth-directed coronal mass ejections (CMEs) have been observed in coronagraph imagery over the past 24 hours. Type II and type IV radio bursts were reported related to C9.4-class flaring from NOAA AR 3638 14:10 UTC on April 24th. The resulting westward CME is estimated to have no impact on Earth.

Coronal holes

A positive polarity mid-latitude coronal hole is currently residing on the central meridian in the southern hemisphere. The high speed stream emanating from it might arrive to Earth on April 28th, possibly superimposed with expected preceding high speed stream arrival.

Solar wind

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) were indicative of background slow solar wind regime. The solar wind velocity was predominantly below 400 km/s. The interplanetary magnetic field (B) was weak with a maximum value of 4.8 nT and a minimum Bz of -3.9 nT. The B field phi angle was alternating between the negative and the positive sector (directed towards and away from the Sun). The solar wind conditions might experience mild enhancements on April 25th - April 28th with possible mild high speed streams encounters related to several positive polarity coronal holes.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet. Quiet to active conditions are anticipated for April 25th with chances for isolated minor storm levels on April26th -April 28th.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux was at background levels and is expected to continue so over the next days, pending any fast eruptive solar activity.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux as measure by GOES 16 and GOES 18 has exceeded the1000 pfu threshold over the past 24h and is expected to repeatedly exceed the 1000 pfu threshold in the upcoming days. The 24h electron fluence was at boundary of nominal to moderate level and is expected to be at moderate levels for the upcoming days.

Today's estimated international sunspot number (ISN): 220, based on 11 stations.

Solar indices for 24 Apr 2024

Wolf number Catania	///
10cm solar flux	199
AK Chambon La Forêt	004
AK Wingst	002
Estimated Ap	142
Estimated international sunspot number	261 - Based on 20 stations

Noticeable events summary

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

All times in UTC

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