Viewing archive of Friday, 28 August 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 Aug 28 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
28 Aug 2015	115	041
29 Aug 2015	115	021
30 Aug 2015	110	017

Bulletin

Solar flaring activity was low with AR 2403 producing a number of C flares this morning. The largest one peaked at 2:51UT at C8 level. The new region in the South-East was numbered 2405. Larger flaring at M level from region 2403 remains fairly likely. The associated warning condition for proton events is maintained. No Earth-directed CME's were recorded in coronagraph data. While solar wind speed continued to drop from around 350 km/s to around 335 km/s, total magnetic field remained elevated to levels in the 10-15nT range with Bz mainly negative and extended periods of pronounced negative values down to -13nT. Yesterday afternoon saw the anticipated sector boundary crossing into the towards sector. The negative Bz values caused unsettled to moderate geomagnetic storm conditions (local K Dourbes 3-6, NOAA Kp 4-6). Solar wind speed is expected to rise under the influence of a high speed stream from a negative polarity coronal hole. Elevated solar wind conditions are hence expected to continue over the first days before subsiding. Consequently, unsettled to minor geomagnetic storm conditions are expected.

Today's estimated international sunspot number (ISN): 043, based on 18 stations.

Solar indices for 27 Aug 2015

Wolf number Catania	///
10cm solar flux	110
AK Chambon La Forêt	056
AK Wingst	041
Estimated Ap	047
Estimated international sunspot number	055 - Based on 18 stations

Noticeable events summary

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

All times in UTC

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