Viewing archive of Saturday, 16 October 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Oct 16 1231 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
16 Oct 2021	082	012
17 Oct 2021	082	010
18 Oct 2021	082	016

Bulletin

Region NOAA 2885 produced a B9.7 flare peaking at 15:16 UT on October 15. The chance for a C flare in the next 24 hours is estimated at 50%, especially from region 2885.

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.

DSCOVR registered a fast forward shock in the solar wind at 00:12 UT on October 16. The solar wind speed jumped from about 300 to 345 km/s, while the magnitude of the Interplanetary Field (IMF) jumped from about 6 to 8 nT and the density jumped from about 4.5 to 6.5 counts/cc. The IMF orientation stayed predominantly towards the Sun. This probably corresponds to the Corotating Interaction Region (CIR) in front of the high speed stream from a negative polarity equatorial coronal hole. Current solar wind speed values are near 400 km/s, and current values for the magnitude of the IMF are about 9 nT. There were no extended time intervals in which Bz was below -5 nT. Enhanced solar wind conditions are expected on October 16, with a gradual return to nominal levels 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.

Quiet to unsettled geomagnetic conditions (K Dourbes between 1 and 3; NOAA Kp between 0 and 2) were registered in the past 24 hours. On October 16, active intervals (K Dourbes = 4) are possible, with a slight chance for minor storm intervals (K Dourbes = 5). Quiet to unsettled geomagnetic levels are expected on October 17 and the first half of October 18. In the second half of October 18, active intervals are possible due to the expected arrival of a high speed stream from a positive polarity coronal hole, with a slight chance for minor storm intervals.

Today's estimated international sunspot number (ISN): 011, based on 22 stations.

Solar indices for 15 Oct 2021

Wolf number Catania	011
10cm solar flux	084
AK Chambon La Forêt	///
AK Wingst	///
Estimated Ap	///
Estimated international sunspot number	011 - Based on 30 stations

Noticeable events summary

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

All times in UTC

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