Viewing archive of Monday, 31 May 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 May 31 1231 UTC

SIDC Forecast

Solar flares

Quiet conditions (<50% probability of C-class flares)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
31 May 2021	075	007
01 Jun 2021	075	010
02 Jun 2021	075	007

Bulletin

The solar activity has been relatively quiet over the past 24 hours, with the X-ray flux below C-level. Two sunspot groups are currently visible on the solar disc. The bipolar region (NOAA AR-2827) has produced several B-class flare while the unipolar region (NOAA AR-2827) has not produced any significant flare. The solar activity is expected to remain mostly low levels over the next 24 hours with possible C-class flare produced by the bipolar region NOAA AR-2827.

No Earth directed Coronal Mass Ejection (CME) has been detected in the available coronagraph imagery.

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 was below the 1000 pfu threshold in the past 24 hours and is expected to remain so during the next 24 hours. The 24h electron fluence was at normal levels in the last 24 hours and is expected to stay at normal levels for the next 24 hours.

The solar wind parameters (as observed by ACE and DSCOVR) show a return towards an ambient background and slow solar wind speed regime. The solar wind speed decreased from 473 km/s to 373 km/s. The interplanetary magnetic field magnitude was below 5.0 nT, and Bz components varied between -3.4 nT and 2.4 nT. A large equatorial coronal hole (negative polarity) has reached the central meridian. The high-speed streams associated with this coronal hole is expected to enhance the solar wind condition in about 3-4 days. There is a slight chance that the coronal mass ejection observed on May 28 provides a glancing blow to the Earth and enhancing the solar wind conditions in the second half of May 31 and June 1.

The geomagnetic conditions were quiet to unsettle over the past 24 hours. The conditions are expected to remain mostly quiet as the Earth is expected to remain in slow solar wind speed regime for the next 24 hours. However, there is a slight chance that the coronal mass ejection of May 28 provides a glancing blow to the Earth, this could result in active geomagnetic activity with a minor storm in the second half of May 31 and on June 1.

Today's estimated international sunspot number (ISN): 029, based on 26 stations.

Solar indices for 30 May 2021

Wolf number Catania	///
10cm solar flux	074
AK Chambon La Forêt	009
AK Wingst	006
Estimated Ap	006
Estimated international sunspot number	027 - Based on 30 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page