Viewing archive of Wednesday, 27 September 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Sep 27 1248 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
27 Sep 2017	091	029
28 Sep 2017	093	013
29 Sep 2017	091	008

Bulletin

Over the past 24 hours solar activity has been low. No significant flares have been recorded. Catania group 57 (NOAA AR region 2683) has been most active, producing one C1.7 flare peaking at 01:03 UT today. Eruptive activity observed on the visible side of the solar disk yesterday is not geoeffective. No Earth directed Coronal Mass Ejections (CMEs) have been detected today. The greater than 10MeV proton flux remained at background levels over the past 24 hours. Solar activity is expected to remain low over the next 24 hours with some probability of C-class flares. The sudden jump of the solar wind speed (up to maximum value of 560 km/s) and simultaneous increase of the density and interplanetary magnetic field magnitude (up to 17 nT) observed at around 07 UT on September 27 (today) indicated arrival of the fast flow associated with the low latitude extension of the northern polar coronal hole. The longer intervals of the southward Bz component (up to -17 nT) and fast solar wind induced minor geomagnetic storm conditions starting at about 06:00 UT on September 27 (local station at Dourbes reported K=4 and NOAA reported Kp=5). We expect active to minor storm conditions (till Kp=5) within next 24 hours due to arrival of the fast solar wind. Isolated episodes of Kp=6 are also not excluded.

Today's estimated international sunspot number (ISN): 040, based on 17 stations.

Solar indices for 26 Sep 2017

Wolf number Catania	046
10cm solar flux	091
AK Chambon La Forêt	013
AK Wingst	005
Estimated Ap	003
Estimated international sunspot number	041 - Based on 24 stations

Noticeable events summary

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

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