Viewing archive of Wednesday, 26 May 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 May 26 1234 UTC

SIDC Forecast

Valid from 1230 UTC, 26 May 2021 until 28 May 2021
Solar flares

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

Geomagnetism

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

Solar protons

Quiet

10cm fluxAp
26 May 2021087018
27 May 2021087024
28 May 2021087007

Bulletin

Beta-gamma region NOAA 2824 and new beta-gamma region 2826 have produced several B flares and two low C flares in the past 24 hours. 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%.

A CME towards the west was first observed at 19:38 UT on May 25 in COR2 A. While this CME could be Earthbound, with an estimated speed of only 270 km/s, it is not expected to be geoeffective.

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 reached moderate levels in the past 24 hours, and may reach moderate levels again in the next 24 hours. The greater than 2 MeV electron fluence has reached moderate levels during the past 24 hours, and may reach moderate levels again in the next 24 hours.

The Interplanetary Magnetic Field (IMF) changed orientation from towards the Sun to away from the Sun around 2:45 UT on May 26. At 11:35 UT on May 26, a fast forward shock was observed in the solar wind as registered by DSCOVR, with solar wind speed jumping from 297 km/s to 357 km/s and IMF magnitude jumping from 3 nT to 9 nT. Bz was never below -5 nT in the past 24 hours. These enhanced solar wind conditions are probably associated with the arrival of several CMEs from May 22 and 23. Solar wind conditions are expected to stay enhanced on May 27.

Quiet geomagnetic conditions (K Dourbes between 1 and 2; NOAA Kp between 0 and 2) were registered in the past 24 hours. Active to minor storm geomagnetic intervals (K Dourbes = 4-5) are possible on May 26 and 27. Quiet to unsettled levels (K Dourbes < 4) are expected on May 28.

Today's estimated international sunspot number (ISN): 036, based on 19 stations.

Solar indices for 25 May 2021

Wolf number Catania039
10cm solar flux084
AK Chambon La Forêt009
AK Wingst004
Estimated Ap004
Estimated international sunspot number040 - Based on 26 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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