Viewing archive of Wednesday, 25 May 2016

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2016 May 25 1230 UTC

SIDC Forecast

Solar flares

Quiet conditions (<50% probability of C-class flares)

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
25 May 2016	094	005
26 May 2016	093	021
27 May 2016	089	013

Bulletin

NOAA 2546 produced the strongest flare of the period, a B9.5 flare peaking at 21:07UT on 24 May. The region remains the largest sunspot group currently visible, producing occasional B-class flares that are often accompanied by jet-like eruptions. The associated coronal mass ejections (CMEs) had no earth-directed component. The other sunspot groups (NOAA 2548 and tiny Catania 81) remained quiet.

Mostly quiet conditions are expected, with a small chance on an isolated C-class flare.

Solar wind speed mostly varied between 380 and 450 km/s. Bz undulated between -3 and +4 nT, with the Interplanetary Magnetic Field directed away from the Sun. A negative coronal hole (CH) on the northern hemisphere started transiting the central meridian around noon on 24 May. Quiet to unsettled geomagnetic conditions were observed.

Quiet to unsettled geomagnetic conditions are expected until the arrival of the co-rotating interaction region (CIR) associated with the wind stream from the small negative southern CH. A sector boundary crossing may precede or coincide with the CIR. The arrival of these structures is possible late on 25 May, but more likely on 26 May, and may result in active geomagnetic conditions with a slight chance on a minor storming episode.

Today's estimated international sunspot number (ISN): 031, based on 11 stations.

Solar indices for 24 May 2016

Wolf number Catania	027
10cm solar flux	094
AK Chambon La Forêt	007
AK Wingst	006
Estimated Ap	006
Estimated international sunspot number	024 - Based on 27 stations

Noticeable events summary

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

All times in UTC

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