Viewing archive of Friday, 20 October 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Oct 20 1230 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
20 Oct 2017	072	015
21 Oct 2017	074	016
22 Oct 2017	074	007

Bulletin

The Sun produced only two very low B flares in the past 24 hours. The probability for a C flare in the next 24 hours is estimated at 25%, mostly from returning NOAA region 2682 which is approaching the East limb. No Earth-directed Coronal Mass Ejections (CMEs) were observed in available coronagraphic imagery. The greater than 10 MeV proton flux was at nominal levels. Solar wind speed measured by DSCOVR increased from about 375 km/s to a maximum around 500 km/s near 21h UT on October 19, with current values around 450 km/s. The Interplanetary Magnetic Field (IMF) was predominantly directed away from the Sun and its magnitude ranged between about 3 and 11 nT. Bz was often below -5 nT between 12h and 18h UT on October 19, which is when solar wind speed was still in its ascending phase. This solar wind with elevated parameters probably originates from the (positive) north polar coronal hole. Quiet to active geomagnetic conditions (K Dourbes between 2 and 4; NOAA Kp between 2 and 4) were registered in the past 24 hours. Active geomagnetic levels (K Dourbes = 4) are possible on October 20 and 21. Quiet to unsettled geomagnetic levels (K Dourbes < 4) are expected on October 22.

Today's estimated international sunspot number (ISN): 000, based on 18 stations.

Solar indices for 19 Oct 2017

Wolf number Catania	000
10cm solar flux	073
AK Chambon La Forêt	022
AK Wingst	014
Estimated Ap	015
Estimated international sunspot number	000 - Based on 31 stations

Noticeable events summary

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

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