Viewing archive of Wednesday, 30 June 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Jun 30 0952 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
30 Jun 2021	093	014
01 Jul 2021	095	017
02 Jul 2021	095	017

Bulletin

X ray flux remained below C level. NOAA region 2835 continued to grow and continues to show mixed polarity in the intermediate spots and the leading part. It is classified as beta- gamma-delta magnetic configuration. NOAA region 2836 is a stable bipolar region and seems to start to decay, while the new region 2837 remains a simple unipolar region. Flaring at C level is likely (mostly from NOAA 2835) over the next 24 hours, with also a chance for a possible M flare.

Related to the dimming of around 5:16UT June 29, as reported yesterday, coronagraph data from STEREO A display a CME towards the West from 11:53UT onwards. SoHO/LASCO coronagraph data are not so clear and the signature is faint. The most clear part is visible from around 6:24UT towards the East. The CME direction and speed are thus hard to establish based on the available coronagraph data. Combined with the location of the source region on disc we are estimating that an arrival of an associated CME is not excluded and could occur around noon July 3, but confidence is low on this forecast. Another CME visible in SoHO/LASCO C2 data around 18:36UT towards the West is originating from the West limb and not expected to affect Earth.

The greater than 10 MeV proton flux was at nominal levels over the past 24 hours and is expected to remain so for the next 24 hours. The greater than 2 MeV electron flux was below the 1000 pfu event threshold. The 24h electron fluence was at normal levels and electron fluence is expected to remain at normal levels during the next days.

Nominal slow Solar wind conditions were observed until 2:47UT when a small fast forward shock occurred. Solar wind speed jumped from 327 km/s to 354 km/s and magnetic field jumped from 3nT to 5nT. Density and temperature approximately doubled. Since then, an increase in magnetic field was seen to build up, reaching a peak of near 10nT around 8UT, with the Bz component being consistently negative and reaching close to -10nT. It appears that this is the compression region ahead of the expected solar wind enhancements associated to the coronal hole that passed central meridian June 27. Solar wind speed is now continuing to rise slowly and is expected to rise further. Phi angle indicated that the interplanetary magnetic field is pointing away from the Sun. Solar wind conditions are expected to remain and become further enhanced. Late on July 1, a possible glancing blow from the June 27 CME may add to the perturbed conditions. And also on July 3 another CME arrival may be expected.

Geomagnetic conditions were quiet to active (NOAA Kp 0-3, local K Dourbes 0-4). The active period was reached in relation to the strongly southward interplanetary magnetic field. Geomagnetic conditions are expected to remain unsettled, with occasional active periods possible.

Today's estimated international sunspot number (ISN): 054, based on 11 stations.

Solar indices for 29 Jun 2021

Wolf number Catania	054
10cm solar flux	093
AK Chambon La Forêt	///
AK Wingst	009
Estimated Ap	006
Estimated international sunspot number	054 - Based on 28 stations

Noticeable events summary

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

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