Viewing archive of Saturday, 16 September 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Sep 16 1355 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
16 Sep 2017	070	022
17 Sep 2017	069	014
18 Sep 2017	068	009

Bulletin

Solar activity remains to be very low without even C-class flares reported during last 48 hours. We expect solar activity to stay at the same low level with isolated C-class flares possible but rather improbable. No Earth directed CMEs have been observed and the solar protons remained at background level in the past 24 hours.

The Earth is still inside the fast solar wind stream (speed of about 700 km/s), associated with a low-latitude extension of the northern polar coronal hole which reached central meridian on September 09. Due to the high solar wind speed of about 710 km/s and longer intervals of the southward Bz component of the interplanetary magnetic field (down to -7 nT) disturbed geomagnetic conditions were reported starting from yesterday late afternoon. The local station at Dourbes reported one interval of K=5 and NOAA reported Kp=5 since 18:00 UT on September 15 and one interval of Kp=6 at 03:00 UT this morning. Presently geomagnetic conditions are unsettled to active, however the solar wind speed is still high and longer intervals of southward Bz might induce active to minor storm conditions in the coming hours.

Today's estimated international sunspot number (ISN): 015, based on 18 stations.

Solar indices for 15 Sep 2017

Wolf number Catania	012
10cm solar flux	073
AK Chambon La Forêt	050
AK Wingst	034
Estimated Ap	040
Estimated international sunspot number	013 - Based on 29 stations

Noticeable events summary

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

All times in UTC

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