Viewing archive of Friday, 16 April 2021

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2021 Apr 16 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
16 Apr 2021	074	014
17 Apr 2021	075	018
18 Apr 2021	074	008

Bulletin

Solar activity remained at very low levels over the last 24 hours. Sunspot group Catania 86 (NOAA 2814) further increased its number of sun spots, remaining magnetic type Beta. Two other unnumbered sunspot groups are visible on the solar disc. One of them was reported to emerged on April 15th close to the centre and visible this morning around S22W15, while the one rotated from the east limb, being close to S22E70. All three active regions currently show low levels of activity. The flaring activity within the next 24 hours is expected to remain low with some chance for C-class flares.

No Earth-directed coronal mass ejections (CMEs) were detected in the available coronagraph imagery.

The greater than 10 MeV proton flux was at nominal levels in the past 24 hours and is expected to remain so in the next 24 hours. The greater than 2MeV electron flux remained under the 1000 pfu threshold and is expected to remain so. The 24h electron fluence was at nominal levels and is expected to be predominantly at nominal in the next 24 hours.

Over the past 24 hours the solar wind parameters (ACE and DSCOVR) registered slight enhancements due to the expected arrival of a high speed stream (HSS) from a negative polarity coronal hole (CH). The total magnetic field reached a magnitude of 10.5 nT with a minimum Bz of -7.4 nT. The solar wind speed is gradually increasing, peaking at 488 km/s, and is expected to increase further.

The geomagnetic conditions over the past 24 hours were quiet to unsettled. Quiet to active geomagnetic conditions are expected in the next 24 hours with a possibility for a minor geomagnetic storm.

Today's estimated international sunspot number (ISN): 037, based on 20 stations.

Solar indices for 15 Apr 2021

Wolf number Catania	///
10cm solar flux	072
AK Chambon La Forêt	019
AK Wingst	014
Estimated Ap	015
Estimated international sunspot number	024 - Based on 23 stations

Noticeable events summary

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

All times in UTC

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