Viewing archive of Tuesday, 14 April 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 Apr 14 1238 UTC

SIDC Forecast

Solar flares

Eruptive (C-class flares expected, probability >=50%)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
14 Apr 2015	148	011
15 Apr 2015	153	014
16 Apr 2015	158	010

Bulletin

Only few low C-class flares were reported during last 24 hours, despite the presence of the complex active region NOAA AR 2321 which maintains beta-gamma-delta configuration of its photospheric magnetic field. The strongest reported flare was the C2.9 flare which peaked at 23:23 UT on April 13. The flare originated from the Catania sunspot group 22 (NOAA AR 2320), situated at that moment at the west solar limb. In the coming hours we expect C-class and also possibly M-class flares, in particular from the Catania sunspot groups 29, 30 and 31 (all together classified as NOAA AR 2321). Full halo CME, first seen in the SOHO LASCO C2 field of view at 02:36 UT on April 14 had no visible on-disc signatures, but it had the associated coronal dimming visible above the solar limb. All this indicates that the CME was the back side event and will therefore not arrive at the Earth. Solar wind speed as well as the interplanetary magnetic field magnitude and temperature started to increase since 05:00 UT this morning indicating possible arrival of the fast solar wind associated with the extended southern polar coronal hole. However, presently the solar wind speed is still slow, having value of about 350 km/s and the interplanetary magnetic field magnitude is about 8 nT. The partial halo CME, first seen in the SOHO LASCO C2 field of view at 23:36 UT on April 12 might arrive at the Earth in the late evening of the April 15 or early morning of April 16. We do not expect strongly disturbed geomagnetic conditions (K index maximum 4) due to the slow speed of the CME. The geomagnetic conditions are currently quiet. The arrival of the fast flow might cause unsettled to active geomagnetic conditions in the coming hours.

Today's estimated international sunspot number (ISN): 077, based on 19 stations.

Solar indices for 13 Apr 2015

Wolf number Catania	137
10cm solar flux	141
AK Chambon La Forêt	007
AK Wingst	006
Estimated Ap	006
Estimated international sunspot number	076 - Based on 28 stations

Noticeable events summary

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

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