Viewing archive of Saturday, 18 April 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 Apr 18 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
18 Apr 2015	152	010
19 Apr 2015	155	010
20 Apr 2015	156	006

Bulletin

Only few low C-class flares were reported in the past 24 hours, and the strongest one was C1.2 flare (peaked at 18:01 UT) on April 17. The flare originated from the Catania sunspot group 32 (NOAA AR 2324). We expect C-class flares and possibly, but not very probably an isolated M-class flare. No Earth directed CMEs were observed during last 24 hours. The Earth is still inside a fast solar wind, although the wind speed is continuously decreasing and it is at the moment 550 km/s. The interplanetary magnetic field magnitude is stable amounting about 5nT. The Bz component of the interplanetary magnetic field is fluctuating between 3 and -5nT. The fast flow from the small low latitude coronal hole at the southern solar hemisphere (between S10 and S30) which crossed central meridian on April 17 might possibly, although not very probable, arrive at the Earth on April 20. The geomagnetic conditions are presently quiet, and we expect quiet to unsettled geomagnetic conditions in the coming hours.

Today's estimated international sunspot number (ISN): 121, based on 13 stations.

Solar indices for 17 Apr 2015

Wolf number Catania	///
10cm solar flux	150
AK Chambon La Forêt	019
AK Wingst	021
Estimated Ap	022
Estimated international sunspot number	090 - 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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