Viewing archive of Friday, 19 April 2013

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2013 Apr 19 1208 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 2013	103	005
20 Apr 2013	100	010
21 Apr 2013	098	006

Bulletin

Seven sunspot groups were reported by Catania today and none of them was particularly active, with only two C-class flares reported in last 24 hours. The strongest flare reported was long duration C5.6 flare peaking at 18:23 UT on April 18, and originating from the Catania sunspot group 43 (NOAA AR 1719) situated at that moment just behind the west solar limb. The partial halo CME, associated with this flare, was first seen in the SOHO/LASCO C2 field of view at 18:36 UT, had angular width of about 180 degrees and projected speed of about 400 km/s (as reported by CACTUS software). The CME was associated with the coronal dimming, EIT wave and a type II radio burst. The solar wind speed has continuously low value of about 280 km/s. The interplanetary magnetic field magnitude is stable and amounts about 4 nT . The fast flow from the small low-latitude coronal hole in the northern hemisphere might arrive at the Earth late today or early tomorrow. The arrival of the fast stream is not very probable and should not result in disturbed geomagnetic conditions. Due to the position of the CME associated active region we do not expect the partial halo CME from April 18 to arrive at the Earth. We expect quiet geomagnetic conditions in the next 48 hours.

Today's estimated international sunspot number (ISN): 052, based on 16 stations.

Solar indices for 18 Apr 2013

Wolf number Catania	086
10cm solar flux	105
AK Chambon La Forêt	005
AK Wingst	002
Estimated Ap	002
Estimated international sunspot number	060 - Based on 20 stations

Noticeable events summary

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

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