Viewing archive of Friday, 15 September 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Sep 15 1230 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
15 Sep 2017	074	032
16 Sep 2017	073	015
17 Sep 2017	073	009

Bulletin

The sunspot group Catania number 55 (NOAA AR 2680), is still the only reported sunspot group on the visible side of the solar disc. Solar activity was very low, with no even C-class flares reported in the past 24 hours. Isolated C-class flares are possible in the coming hours, but very improbable. The particle event, associated with the X8.2 flare has finished, the proton fluxes with >10 MeV went bellow the event threshold at about 18 UT on September 14. No Earth directed CMEs have been observed in the past 24 hours.

The Earth is presently inside the fast solar wind stream with the speed of about 660 km/s. The interplanetary magnetic field magnitude is about 6 nT. 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 afternoon and early this morning moderate geomagnetic storm conditions: NOAA Kp = 6 (with local K = 5 at Dourbes). The interaction region was followed by the fast stream, with the solar wind speed reaching 770 km/s. Since the solar wind speed is still rather high, longer intervals of the negative value of the Bz component of interplanetary magnetic field might still induce active to minor storm conditions. Geomagnetic conditions are presently active, and we expect active to possibly minor storm level (Kp up to 5) conditions in the coming hours.

Today's estimated international sunspot number (ISN): 013, based on 24 stations.

Solar indices for 14 Sep 2017

Wolf number Catania	012
10cm solar flux	074
AK Chambon La Forêt	046
AK Wingst	029
Estimated Ap	028
Estimated international sunspot number	013 - Based on 27 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