Viewing archive of Sunday, 26 August 2018

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2018 Aug 26 1305 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Moderate (ISES: Major) magstorm expected (A>=50 or K=6)

Solar protons

Quiet

	10cm flux	Ap
26 Aug 2018	072	076
27 Aug 2018	071	048
28 Aug 2018	071	011

Bulletin

Solar activity was very low with the largest flare a B1.9 flare peaking at 21:28UT from NOAA AR 2720. Both regions on disk became stable or in decay over the period. X-ray flux is expected to remain below C level.

No Earth directed CMEs have been observed in coronagraph data.

Proton flux levels were at background values and are expected to remain so.

Solar wind conditions saw the passing of a magnetic cloud associated to the August 20 CME. Soon after the start of the period total magnetic field jumped over 10 nT and continued to increase over the period, reaching close to 19nT. Bz was initially positive but soon rotated into a pronounced and persistent Southward orientation with Bz negative almost the entire period and reaching down to -17nT. Solar wind speed was between 360-450 km/s. Solar wind conditions are expected to remain enhanced in the wake of the passing cloud but should start to recover to nominal conditions in the next 48 hours.

Geomagnetic conditions have reached minor and moderate storm levels locally (K Dourbes 5 and 6) and even moderate and major storm levels on a planetary level (NOAA Kp 6 and 7) during the morning as a result of the pronounced and persistent Southward oriented interplanetary magnetic field. In the wake of the CME passage, geomagnetic conditions may still see minor or moderate storm levels in the next 24 hours but a return to unsettled conditions should be expected within the next 48 hours.

Today's estimated international sunspot number (ISN): 030, based on 18 stations.

Solar indices for 25 Aug 2018

Wolf number Catania	///
10cm solar flux	072
AK Chambon La Forêt	043
AK Wingst	017
Estimated Ap	016
Estimated international sunspot number	034 - Based on 27 stations

Noticeable events summary

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

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