Viewing archive of Sunday, 21 April 2019

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2019 Apr 21 1230 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
21 Apr 2019	069	004
22 Apr 2019	069	003
23 Apr 2019	068	006

Bulletin

Solar activity was at very low levels. Small active region NOAA 2739 decayed further and is expected to become spotless later today. CACTus revealed a coronal mass ejection (CME) from the west limb starting around 05:00UT in LASCO/C2 coronagraphic images. This CME was most likely associated with eruptive processes in NOAA 2738 from behind the west limb, as evident from SDO EUV imagery. None of the observed CMEs had an earth- directed component. The greater than 10 MeV proton flux was at nominal values. An equatorial negative polarity coronal hole (CH) is transiting the central meridian.

Solar activity is expected to remain at very low levels.

Solar wind speed was fairly steady between mostly 320 and 350 km/s (DSCOVR). Bz varied between -5 and +4 nT. The interplanetary magnetic field was predominantly directed away from the Sun (positive sector). Geomagnetic conditions were at quiet levels, with an isolated unsettled interval (06-09UT) recorded at Dourbes.

Mostly quiet geomagnetic conditions are expected, with a chance on an isolated unsettled episode. Late on 23 or on 24 April, geomagnetic activity is expected to increase following the arrival of the wind stream from an equatorial negative polarity coronal hole.

Today's estimated international sunspot number (ISN): 007, based on 25 stations.

Solar indices for 20 Apr 2019

Wolf number Catania	///
10cm solar flux	070
AK Chambon La Forêt	008
AK Wingst	///
Estimated Ap	005
Estimated international sunspot number	012 - Based on 31 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page