Viewing archive of Monday, 3 April 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Apr 03 1231 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
03 Apr 2017	108	003
04 Apr 2017	103	008
05 Apr 2017	100	005

Bulletin

Solar activity was at high levels during the period. Four M-class flares were recorded, the strongest being an M5.7 event peaking at 20:33UT. NOAA 2644 has developed a complex magnetic configuration and was the source of all important flaring. This region is approaching the west limb. NOAA 2645 was quiet, despite the important delta structure in its trailing portion. A long duration M2 flare peaking at 18:38UT affected the 20UT value of the 10.7cm radio flux. No earth-directed coronal mass ejections (CMEs) were observed in available coronagraphic imagery. The greater than 10MeV proton flux was at nominal levels.

Further M-class flaring is expected, with a chance on an X-class flare. As both NOAA 2644 and 2645 are in the western solar hemisphere, a major flare from any of these regions may drive the greater than 10MeV proton levels above event threshold.

Solar wind speed declined from about 510 km/s to values around 420 km/s. Bz fluctuated between -3 nT and +2 nT. The interplanetary magnetic field was mostly directed towards the Sun, except for the first 3 and last 3 hours of the period (away from the Sun). There's a small chance that the particle stream from a weak positive coronal hole may affect the earth environment on 4 April.

The geomagnetic field was at quiet to unsettled levels and is expected to remain so.

Today's estimated international sunspot number (ISN): 102, based on 20 stations.

Solar indices for 02 Apr 2017

Wolf number Catania	///
10cm solar flux	112
AK Chambon La Forêt	011
AK Wingst	008
Estimated Ap	008
Estimated international sunspot number	084 - Based on 36 stations

Noticeable events summary

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

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