Viewing archive of Sunday, 28 May 2023

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2023 May 28 1259 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 May 2023	158	013
29 May 2023	158	015
30 May 2023	158	014

Solar Active Regions and flaring

Solar flaring activity remained at moderate levels with an impulsive M1.0-class flare, start time 10:21 UTC, end time 10:55 UTC, peak time 10:36 UTC on May 28th from NOAA AR 3315 (beta-gamma-delta). This region underwent major developed increasing in area, complexity and number of sunspots, becoming the largest and most complex active region on the visible solar disc. Isolated low C-class flaring was produced by NOAA AR 3316 (beta), which shows minor changes, by NOAA AR 3311 (beta-gamma), which experienced further decay, and by NOAA AR 3314, which evolved into beta-delta magnetic configuration. A C6.2-class flare was produced by NOAA AR 3312 (beta) which remained small and relatively simple. NOAA AR 3310 (alpha) underwent further decay and NOAA AR 3313 (alpha) remained stable. Both regions were inactive. The solar flaring activity is expected to be at low to moderate levels over the next days with 50% chances for M-class flaring.

Coronal mass ejections

No Earth-directed coronal mass ejections (CMEs) were detected in the available coronagraph imagery.

Solar wind

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) Solar wind parameters reflected low density slow solar wind conditions, which could be related to the nearby passage of the May 25th south-west CMEs. The solar wind velocity varied in the range of 366 km/s to 524 km/s. The interplanetary magnetic field was weak with a maximum value of 5.7 nT and a minimum Bz of -5.8 nT. The B field was predominantly in the negative sector (directed towards the Sun) with some intervals in the positive sector (directed away from the Sun). The solar wind conditions are expected to be mostly at slow solar wind levels throughout the day with possible minor influence from nearby passage of May 25th CMEs. Further enhancements are possible on May 29th and May 30th with the expected arrival of a high speed stream from a negative polarity coronal hole.

Geomagnetism

The geomagnetic conditions over the past 24 hours were quiet to unsettled. Quiet to unsettled geomagnetic conditions are expected over the next 24 hours with chances for isolated active conditions due to possible influence from nearby passage of May 25th CMEs. Quiet to active conditions are expected for May 29th and May 30th with possible isolated minor storm levels.

Proton flux levels

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

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux started above the 1000 pfu threshold on May 27th and has returned back to nominal levels on May 28th. The greater than 2 MeV electron flux is expected to be below the 1000 pfu threshold in the upcoming days. The 24h electron fluence was at moderate levels and is expected to remain at moderate level for the day and then decrease to nominal levels over the next days.

Today's estimated international sunspot number (ISN): 148, based on 20 stations.

Solar indices for 27 May 2023

Wolf number Catania	///
10cm solar flux	157
AK Chambon La Forêt	///
AK Wingst	004
Estimated Ap	006
Estimated international sunspot number	137 - Based on 29 stations

Noticeable events summary

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

All times in UTC

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