Viewing archive of Friday, 16 October 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 Oct 16 1230 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

Active conditions expected (A>=20 or K=4)

Solar protons

Quiet

	10cm flux	Ap
16 Oct 2015	112	017
17 Oct 2015	116	026
18 Oct 2015	120	012

Bulletin

NOAA 2434 increased its sunspot area and developed a delta structure in its leading portion. Its flaring frequency and intensity increased with a total of 11 C-class flares and 2 impulsive M1.1 flares, peaking resp. at 23:31UT and 06:16UT. Old active region NOAA 2420, currently still behind the northeast limb, announced its return by producing a C4.9 flare at 23:05UT. The leading portion of old active region 2422 has started to round the southeast limb. The other sunspot regions have been quiet. Based on currently available coronagraphic imagery, no earth-directed coronal mass ejections (CMEs) have been observed.

There's a good chance on more M-class flares, from NOAA 2434 as well as from the returning regions NOAA 2420 and NOAA 2422.

Solar wind speed showed a declining trend and ranged between 450 km/s and 360 km/s. Bz was mostly negative with values near -7 nT until about 08:00UT, when it gradually turned positive with values up to +3 nT. This coincided with a change in the direction of the interplanetary magnetic field (IMF) from mostly negative (towards the Sun) to positive (away from the Sun). Quiet to unsettled geomagnetic conditions were observed.

Mostly quiet to active geomagnetic conditions are expected. A minor geomagnetic storming episode on 16-17 October remains possible as Earth is still expected to pass through the high speed stream from the eastmost trans-equatorial extension of the northern coronal hole.

Today's estimated international sunspot number (ISN): 049, based on 09 stations.

Solar indices for 15 Oct 2015

Wolf number Catania	///
10cm solar flux	107
AK Chambon La Forêt	017
AK Wingst	012
Estimated Ap	010
Estimated international sunspot number	050 - Based on 16 stations

Noticeable events summary

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

All times in UTC

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