Viewing archive of Friday, 27 January 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Jan 27 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
27 Jan 2017	082	022
28 Jan 2017	081	017
29 Jan 2017	080	007

Bulletin

Solar activity was very low. B-class flare production by NOAA 2629 pretty much stalled. NOAA 2627, now spotless, produced the strongest event of the period: an isolated B5 flare peaking at 10:45UT. NOAA 2628 showed some filament activity in its middle portion around midnight. No earth- directed coronal mass ejections (CMEs) were observed in available coronagraphic imagery. The greater than 10MeV proton flux was at nominal levels.

Mostly quiet flaring conditions are expected, with a small chance on a C-class event.

Around 26/13:45UT January, solar wind speed gradually increased from an initial 375 km/s up to values near 670 km/s around 06UT on 27 January. This is the High Speed Stream (HSS) from the positive equatorial coronal hole (CH), arriving somewhat earlier than expected. It was preceded by a co- rotating interaction region (CIR) that drove a weak shock on 26/07:12UT January. Bz oscillated wildly between -12 nT and +13 nT, preventing the development of a geomagnetic storm. Since 06UT, Bz varied between +5 nT and -5 nT, and wind speed at 560 km/s. The interplanetary magnetic field was mostly directed away from the Sun.

The geomagnetic field was at quiet to active levels. The earth environment will probably remain under the influence of the HSS until at least 28 January. Quiet to active geomagnetic conditions are expected, with a minor storming episode not excluded.

Today's estimated international sunspot number (ISN): 027, based on 16 stations.

Solar indices for 26 Jan 2017

Wolf number Catania	053
10cm solar flux	083
AK Chambon La Forêt	035
AK Wingst	012
Estimated Ap	015
Estimated international sunspot number	041 - Based on 31 stations

Noticeable events summary

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

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