Viewing archive of Friday, 15 May 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 May 15 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
15 May 2015	140	011
16 May 2015	138	012
17 May 2015	136	018

Bulletin

NOAA 2339 and 2342 were the only sunspot regions actively producing low-level C-class flares. NOAA 2339 was the source of the strongest flare of the period, a C4.8 peaking at 17:53UT. Some opposite polarity flux has emerged in its trailing section. NOAA 2342 produced two C2 flares peaking resp. at 14:08UT and 00:11UT, related to eruptive phases of the group filament. An active region is rounding the southeast solar limb and was responsible for a C1 flare (06:50UT). No earth-directed coronal mass ejections (CMEs) have been observed.

Further C-class flaring is expected, with a chance on an M-class flare.

Solar wind speed declined from its initial value near 700 km/s to its current 530 km/s as Earth is gradually exiting the high speed stream (HSS) from the recurrent negative polarity coronal hole (CH). Bz oscillated mostly between -4 and +4 nT. Quiet to unsettled geomagnetic conditions were observed. A recurrent positive polarity CH is transiting the central meridian.

The arrival of the 13 May CME is expected late 17 - early 18 May, slightly preceding or nearly coinciding with the expected arrival of the HSS from the aforementioned positive CH. Until then, quiet to unsettled geomagnetic conditions are expected, with a chance on an active episode.

Today's estimated international sunspot number (ISN): 090, based on 17 stations.

Solar indices for 14 May 2015

Wolf number Catania	///
10cm solar flux	145
AK Chambon La Forêt	017
AK Wingst	010
Estimated Ap	011
Estimated international sunspot number	119 - Based on 25 stations

Noticeable events summary

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

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