Viewing archive of Thursday, 27 May 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 May 27 1231 UTC

SIDC Forecast

Valid from 1230 UTC, 27 May 2021 until 29 May 2021
Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

10cm fluxAp
27 May 2021088030
28 May 2021088012
29 May 2021088007

Bulletin

The Sun has produced six low C flares in the past 24 hours. The brightest flare was a C3.8 flare emitted by beta-gamma region NOAA 2826, which peaked at 23:24 UT on May 26. The chance for a C flare in the next 24 hours is estimated at 90%, while the chance for an M flare is estimated at 10%.

No Earth-directed Coronal Mass Ejections (CMEs) were observed in available coronagraphic imagery.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours. The greater than 2 MeV electron flux has slightly exceeded the 1000 pfu threshold in the past 24 hours, and has since decreased to normal levels. There is a chance for moderate greater than 2 MeV electron flux levels in the next 24 hours due to CME effects. The greater than 2 MeV electron fluence was at normal levels during the past 24 hours. There is a chance for moderate greater than 2 MeV electron fluence levels in the next 24 hours, due to CME effects.

The solar wind speed as registered by DSCOVR increased from about 345 km/s to about 420 km/s in the past 24 hours. The Interplanetary Magnetic Field (IMF) was predominantly oriented orientation away from the Sun and its magnitude varied between about 3 and 17 nT, with current values around 9 nT. Bz was several times below -5 nT for extended intervals, and below -10 nT between about 16:30 and 17:15 UT on May 26. Solar wind conditions are expected to stay enhanced on May 27 and to gradually decline on May 28.

Unsettled to minor storm geomagnetic conditions (K Dourbes between 3 and 5; NOAA Kp between 3 and 5) were registered in the past 24 hours. Active geomagnetic intervals (K Dourbes = 4) are possible on May 27 and 28, with a chance for minor storm geomagnetic levels (K Dourbes = 5). Quiet to unsettled levels (K Dourbes < 4) are expected on May 29.

Today's estimated international sunspot number (ISN): 042, based on 19 stations.

Solar indices for 26 May 2021

Wolf number Catania037
10cm solar flux088
AK Chambon La Forêt039
AK Wingst015
Estimated Ap018
Estimated international sunspot number039 - Based on 32 stations

Noticeable events summary

DayBeginMaxEndLocStrengthOP10cmCatania/NOAARadio burst types
None

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

All times in UTC

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