Viewing archive of Monday, 19 April 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Apr 19 1300 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
19 Apr 2021	078	016
20 Apr 2021	076	013
21 Apr 2021	075	009

Bulletin

There are presently several active regions observed on the visible side of the Sun, majority of them have very simple configuration of the photospheric magnetic field. The most complex one is Catania sunspot group 87 (NOAA AR 2816) which has beta configuration of its photospheric magnetic field. Solar flaring activity is low, with only few B-class and no C-class flares reported during last 24 hours. Majority of the observed flares originated from the active region that is rotating from behind of the East solar limb. This region was also source of the fast CME reported yesterday. We expect such a low level of flaring activity to persist in the coming hours, with an isolated C-class flares possible but not very probable. During last 24 hours no Earth directed CMEs were observed in coronagraph data, and the proton flux levels remained at background values.

The greater than 2MeV electron flux crossed the 1000 pfu threshold this morning and it is expected to remain above the threshold for long periods throughout April 19th.

The high solar wind speed and the longer interval of the negative value of the Bz componente of the interplanetary magnetic field induced active conditions … The local station at Dourbes reported longer interval of the Kp=4 at around midnight, while NOAA reported also several intervals of the Planetary K-index, K=4. The solar wind speed is still high and longer intervals of the negative Bz component of the interplanetary magnetic field might result in disturbed geomagnetic conditions, with active to minor storm conditions possible in the coming hours.

Today's estimated international sunspot number (ISN): 033, based on 20 stations.

Solar indices for 18 Apr 2021

Wolf number Catania	///
10cm solar flux	078
AK Chambon La Forêt	025
AK Wingst	020
Estimated Ap	020
Estimated international sunspot number	017 - Based on 25 stations

Noticeable events summary

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

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