Viewing archive of Sunday, 28 April 2024

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2024 Apr 28 1241 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
28 Apr 2024	152	013
29 Apr 2024	150	011
30 Apr 2024	148	014

Solar Active Regions and flaring

Solar flaring activity was at moderate levels over the past 24 hours with two M-class flares. There are 9 numbered active regions on the visible solar disc with NOAA AR 3654 (beta-gamma) being by far the largest and the most complex, solely responsible for the moderate flaring. The strongest activity was a M3.0 flare, start time 21:29 UTC, end time 21:49 UTC, peak time 21:40 UTC on April 27th. The solar flaring activity is expected to be at low to moderate levels over the next days with possible isolated M-class flaring from NOAA AR 3654.

Coronal mass ejections

A very faint and slow coronal mass ejection (CME) was observed by LASCO/C2 to lift off the solar disc to the south-west after 11:00 UTC on April 27th. The CME might be related to earlier C2.6 flaring (peak time 09:05 UTC on April 27th) from NOAA 3654. This CME is very faint, not clearly visible in STEREO A coronagraph data and is not expected to produce significant impact on Earth. Should any of the plasma arrive, possibly on May 1st, it will probably be mixed with high speed streams on its way. No other Earth-directed CMEs have been observed in the available coronagraph imagery over the past 24 hours.

Coronal holes

A long negative polarity coronal hole stretching from high northern latitudes down to the equator continues to reside on the central meridian. The high speed stream emanating from it might arrive to Earth on May 1st.

Solar wind

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) remained enhanced, possibly under the mixed influence of a glancing blow ICME arrival and high speed stream (HSS) from a positive polarity coronal hole. The solar wind velocity was predominantly in the range of 400 to 500 km/s. The interplanetary magnetic field (B) had a maximum value of 12.8 nT with a minimum Bz of -9.6 nT. The B field phi angle was predominantly in the positive sector (directed away from the Sun). The solar wind conditions are expected to remain mildly elevated throughout April 28th with possible new mild high speed stream arrivals on April 28th and May 1st.

Geomagnetism

The geomagnetic conditions over the past 24 hours were at quiet to active. Mostly quiet to active conditions are expected for April 27th - April 30th with remaining small chances for isolated minor storms.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux was at background levels and is expected to remain so over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux as measured by GOES 16 and GOES 18 was below the1000 pfu threshold over the past 24 hours and is expected to remain so in the upcoming days. The 24h electron fluence was at nominal levels and is expected to remain so in the upcoming days.

Today's estimated international sunspot number (ISN): 139, based on 08 stations.

Solar indices for 27 Apr 2024

Wolf number Catania	///
10cm solar flux	153
AK Chambon La Forêt	021
AK Wingst	014
Estimated Ap	014
Estimated international sunspot number	148 - Based on 18 stations

Noticeable events summary

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

All times in UTC

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