Viewing archive of Tuesday, 15 September 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 Sep 15 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
15 Sep 2015	101	016
16 Sep 2015	104	020
17 Sep 2015	106	018

Bulletin

On 14 September around 17:00UT, a small bipolar region gradually emerged near and in front of NOAA 2415's leading portion. The magnetic interaction resulted in a series of low-level C-class flares, the strongest being a C1.3 flare peaking at 05:19UT. The other 3 sunspot regions were quiet. No earth-directed coronal mass ejections were observed.

More, mostly low-level, C-class flaring is expected, with a small chance on an M-class flare from NOAA 2415.

Solar wind speed varied between 450 and 550 km/s during the period. Bz undulated between -8 and +6 nT, with the interplanetary magnetic field pointing away from the Sun. Quiet to active conditions were observed, with a single minor storming episode during the afternoon of 14 September. The trailing transequatorial extension of a wide northern coronal hole is about to start its transit over the central meridian.

Mostly active geomagnetic conditions are expected over the next few days, with another episode of minor storming not excluded. Minor to moderate geomagnetic storming is expected on 18 and 19 September.

Today's estimated international sunspot number (ISN): 063, based on 15 stations.

Solar indices for 14 Sep 2015

Wolf number Catania	068
10cm solar flux	097
AK Chambon La Forêt	039
AK Wingst	020
Estimated Ap	021
Estimated international sunspot number	052 - Based on 26 stations

Noticeable events summary

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

All times in UTC

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