Viewing archive of Tuesday, 28 November 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Nov 28 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
28 Nov 2017	074	009
29 Nov 2017	073	013
30 Nov 2017	073	005

Bulletin

Solar activity was at very low levels. NOAA 2689 is the only visible sunspot group and is gradually decaying. The prominent 40 degrees long filament in the SW quadrant was quiet. No earth-directed coronal mass ejections (CMEs) were observed in available coronagraphic imagery. The greater than 10 MeV proton flux was at nominal levels.

Quiet flaring conditions are expected, with a slight chance on an isolated C-class flare.

Earth was under the influence of the wind stream from the extensions of the negative polar coronal hole (CH). Solar wind speed peaked near 490 km/s around 14UT and again around 01UT (DSCOVR), ending the period with values around 440 km/s (ACE). Bz was mostly positive, except for a period from 23UT till 01UT with sustained negative values around -8 nT. The interplanetary magnetic field was mostly directed towards the Sun.

The geomagnetic field was quiet throughout the period, except for the 00-03UT interval when Kp was at active levels. Quiet to unsettled conditions are expected as Earth remains under the influence from the weak CH wind stream. A glancing blow from the 25 November CME late on 28 or on 29 November may add to the geomagnetic unrest and result in unsettled to active conditions.

Today's estimated international sunspot number (ISN): 015, based on 19 stations.

Solar indices for 27 Nov 2017

Wolf number Catania	015
10cm solar flux	074
AK Chambon La Forêt	013
AK Wingst	006
Estimated Ap	004
Estimated international sunspot number	017 - Based on 13 stations

Noticeable events summary

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

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