Viewing archive of Thursday, 21 December 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Dec 21 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
21 Dec 2017	075	005
22 Dec 2017	076	007
23 Dec 2017	077	032

Bulletin

A couple of low level B flares were recorded from Catania group 67 (NOAA region 2692) which has become a bipolar region and has shown clear growth and development of its magnetic complexity. Chances for possible C flaring have hence increased but are still low. No Earth directed CMEs have been observed in coronagraph data. Proton flux values are at background levels and are expected to remain so.

Solar wind was nominal with solar wind speed decreasing from near 450 km/s to around 400 km/s and total magnetic field in the 3-4nT range. Solar wind conditions may increase slightly. However, the leading part of the previously elongated coronal hole, that now seems to have become detachedv is not expected to result in any significant high speed stream effects. The more significant high speed stream influence from the trailing part of that previously elongated coronal hole is expected to increase Solar wind conditions from around noon December 23. Geomagnetic conditions were quiet (both local K Dourbes and NOAA Kp 0-2). They are expected to remain at quiet to unsettled levels but increasing towards noon December 23 when active periods and possibly minor storms become possible under the influence of the anticipated high speed stream.

Today's estimated international sunspot number (ISN): 020, based on 07 stations.

Solar indices for 20 Dec 2017

Wolf number Catania	///
10cm solar flux	074
AK Chambon La Forêt	008
AK Wingst	006
Estimated Ap	005
Estimated international sunspot number	014 - Based on 12 stations

Noticeable events summary

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

All times in UTC

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