Viewing archive of Thursday, 28 September 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Sep 28 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Major (ISES: Severe) magstorm expected (A>=100 or K>=7)

Solar protons

Quiet

	10cm flux	Ap
28 Sep 2017	092	071
29 Sep 2017	090	017
30 Sep 2017	089	006

Bulletin

Over the past 24 hours solar activity has been very low. Three numbered active regions on the visible side of solar disk reduced their magnetic complexity (from Beta to Alpha class) and have not shown any flaring activity. No Earth directed Coronal Mass Ejections (CMEs) have been detected. 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 a small chance of C-class flares. The Earth is presently inside the fast solar wind stream with the speed of about 710 km/s. The interplanetary magnetic field magnitude decreased from 14 nT till about 4 nT over the past 24 hours. Arrival of the interaction region between the slow and the fast solar wind from a low-latitude extension of the northern polar coronal hole induced yesterday at 18UT moderate geomagnetic storm conditions: NOAA Kp = 6 (with local K = 4 at Dourbes). The interaction region was followed by the fast stream, with the solar wind speed reaching 690 km/s which induced strong geomagnetic storm at 03UT today: NOAA Kp = 7 (with local K = 5 at Dourbes). The solar wind speed is still rather high, however interplanetary magnetic field variations slightly decreased few hours ago. Geomagnetic conditions are presently at minor storm level (Kp = 5 from 12 UT today), and we expect active to minor storm level (Kp up to 5) conditions in the coming hours.

Today's estimated international sunspot number (ISN): 048, based on 19 stations.

Solar indices for 27 Sep 2017

Wolf number Catania	///
10cm solar flux	091
AK Chambon La Forêt	064
AK Wingst	034
Estimated Ap	035
Estimated international sunspot number	042 - Based on 26 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page