Viewing archive of Sunday, 17 October 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Oct 17 1231 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
17 Oct 2021	079	007
18 Oct 2021	080	016
19 Oct 2021	080	019

Bulletin

The Sun did not produce any C flares in the past 24 hours. The chance for a C flare in the next 24 hours is estimated at 15%.

No Earth-directed Coronal Mass Ejections (CMEs) were observed in available coronagraphic imagery.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours. The greater than 2 MeV electron flux was at nominal levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours. The greater than 2 MeV electron fluence was at nominal levels in the past 24 hours, and is expected to stay at nominal levels in the next 24 hours.

The solar wind speed as registered by DSCOVR varied between about 345 and 420 km/s in the past 24 hours, with current values around 350 km/s. The Interplanetary Field (IMF) was oriented away from the Sun and its magnitude varied between about 4 and 10 nT, with current values around 9 nT. Bz has been below -5 nT from 8:20 UT on October 17 until now, with a minimum around -8 nT. Nominal solar wind levels are expected on October 17 and the first half of October 18. In the second half of October 18, a high speed stream from a positive polarity coronal hole is expected to arrive near Earth, which will likely lead to enhanced solar wind levels in the second half of October 18 and on October 19. Late on October 19 or on October 20, the Earth may encounter the high speed stream from an extension of the (negative polarity) South polar crown coronal hole.

Quiet geomagnetic conditions (K Dourbes between 0 and 2; NOAA Kp between 0 and 3) were registered in the past 24 hours. On October 17 and in the first half of October 18, quiet to unsettled geomagnetic levels (K Dourbes < 4) are expected. Active intervals (K Dourbes = 4) are possible in the second half of October 18 and on October 19, due to the expected arrival of a high speed stream from a positive polarity coronal hole, with a slight chance for minor storm intervals (K Dourbes = 5).

Today's estimated international sunspot number (ISN): 000, based on 18 stations.

Solar indices for 16 Oct 2021

Wolf number Catania	///
10cm solar flux	078
AK Chambon La Forêt	///
AK Wingst	///
Estimated Ap	///
Estimated international sunspot number	011 - 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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