Viewing archive of Wednesday, 3 November 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Nov 03 1253 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Moderate (ISES: Major) magstorm expected (A>=50 or K=6)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
03 Nov 2021	097	018
04 Nov 2021	096	087
05 Nov 2021	095	048

Bulletin

The strongest flare of the period was just a C1 flare from NOAA active region 2887 which is now approaching the West limb. NOAA region 2891 (source of the M flare yesterday) remained mostly calm (with only an occasional B flare) as did the simple unipolar region 2893. NOAA region 2891 remains the most significant region in terms of flaring potential with opposite polarityfield concentrations in the trailing area. Overall C flares are expected with a slight possibility for an M flare.

The available STEREO COR2 cornagraph images indicate that the speed in the direction of the Earth, of the CME associated to the M1.7 flare, is somewhat faster than originally estimated. It is now estimated that the arrival may occur from noon tomorrow November 4 onwards.

Some new CMEs are visible in SoHO LASCO C2 imagery. From 12:36UT onwards a CME towards the (South-)West occurs at the same time as some fronts towards the East and the North. These are judged to be independent and the CMEs are not expected to be Earth directed. Around and after 21:24UT similar but stronger cotemporal occurrences of CME's towards the West and East are recorded but they are again judged to be independent and not expected to be Earth directed.

The more than 10MeV proton flux remained slightly enhanced but below the event threshold. A further gentle decay is expected but there remains some possibility of a proton event. The greater than 2 MeV electron flux was below the 1000 pfu threshold. The 24h electron fluence is at normal levels and expected to be at normal to moderate levels over the next days.

Solar wind showed a continued but declining high speed stream regime. Solar wind speed gently decreased from over 600 km/s to now within the 510-560 km/s range. The magnitude of the interplanetary magnetic field went under 5nT with an insignificant Bz component. The magnetic field orientation indicated connection with a positive polarity sector. Solar wind is expected to remain enhanced over the next 24-48 hours with perturbations from a series of CMEs expected from early tomorrow November 4, and into November 5.

Some active geomagnetic conditions were recorded early in the period (K=4), but geomagnetic conditions were mostly quiet to unsettled (NOAA Kp and local K Dourbes 1-3). Geomagnetic conditions are expected to reach minor or moderate storm levels associated to the expected CME arrivals on November 4 and into November 5.

Today's estimated international sunspot number (ISN): 038, based on 14 stations.

Solar indices for 02 Nov 2021

Wolf number Catania	///
10cm solar flux	097
AK Chambon La Forêt	021
AK Wingst	018
Estimated Ap	019
Estimated international sunspot number	042 - Based on 22 stations

Noticeable events summary

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

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