Viewing archive of Saturday, 20 April 2024

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2024 Apr 20 1231 UTC

SIDC Forecast

Solar flares

M-class flares expected (probability >=50%)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
20 Apr 2024	220	017
21 Apr 2024	215	022
22 Apr 2024	210	017

Solar Active Regions and flaring

Solar flaring activity was at moderate levels, with multiple C-class flares and one M-class flare recorded in the past 24 hours. The largest flare of the period was an M1.0 flare, peaking at 13:06 UTC on Apr 19, associated with NOAA AR 3647 (beta-delta class). There are currently 14 numbered active regions on the visible disk. NOAA AR 3639 (beta-gamma) is the largest region on disk but was inactive. NOAA AR 3635 is expected to rotate over the west limb in the next hours. Other regions on the disc have simple configuration of their photospheric magnetic field (alpha and beta). The solar flaring activity is expected to be at moderate levels over the next 24 hours, with M-class flares possible and a low chance for X-class flare.

Coronal mass ejections

No Earth-directed CMEs have been detected in the available coronagraph imagery over the past 24 hours.

Solar wind

Over the past 24 hours, the solar wind parameters were slightly disturbed under the ICME influence. The total magnetic field reached 18 nT at 14:13 UTC on April 19, later decreasing to the values around 5 nT. The solar wind speed ranged between 400 km/s and 550 km/s. The southward component of the interplanetary magnetic field fluctuated between -16 nT and 7 nT. The interplanetary magnetic field phi angle varied between being directed towards the Sun to being directed away from the Sun. The effects of the CME are expected to slowly wane in the next 24 hours with a chance of a further enhancement on Apr 20 - Apr 21 due to the arrival of a high- speed stream from a negative polarity coronal hole and anticipated arrival of CMEs from Apr 17 - Apr 18, however with low confidence.

Geomagnetism

Geomagnetic conditions reached strong storm levels globally (NOAA-Kp = 7) between 18:00 and 21:00 UTC on Apr 19. Locally over Belgium, only minor geomagnetic storm conditions were observed (K-Bel = 5). Conditions then reduced to quiet to unsettled levels. The strong storm period was reached due to the prolonged period of negative Bz. Predominantly unsettled geomagnetic conditions are expected on Apr 20-21 with a chance of reaching active and minor storm conditions due to expected HSS arrival and potential CMEs arrivals.

Proton flux levels

Over the past 24 hours the greater than 10 MeV GOES proton flux was at nominal levels and is expected to remain so with possible enhancements in case of increased levels of solar activity over the next days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux, as measured by the GOES-16 satellite, remained below the 1000 pfu threshold. It is expected to remain below the threshold during the next 24 hours. The 24 hour electron fluence was at normal levels and is expected to remain at these levels for the following 24 hours.

Today's estimated international sunspot number (ISN): 218, based on 13 stations.

Solar indices for 19 Apr 2024

Wolf number Catania	///
10cm solar flux	213
AK Chambon La Forêt	042
AK Wingst	041
Estimated Ap	040
Estimated international sunspot number	231 - Based on 19 stations

Noticeable events summary

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

All times in UTC

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