Viewing archive of Wednesday, 20 May 2015

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2015 May 20 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

	10cm flux	Ap
20 May 2015	105	015
21 May 2015	102	012
22 May 2015	101	007

Bulletin

Solar activity was low with 2 low level C flares. A C1.3 flare peaking at 04:04UT originated from the new region in the northern hemisphere (now numbered NOAA 2351) and a C1.6 flare peaked at 8:12UT from region 2349. All regions on disk appear fairly simple. Quiet conditions are expected with a chance for isolated low level C flares. Again a number of small eruptions were recorded: one from around 25N20W between 02:00UT and 03:00UT, and one associated to the C1.6 flare from region 2349. Although neither of those appears particularly threatening, no coronagraph data were available yet to assess possible Earth directed components. Solar wind conditions are determined by a high speed stream from a positive polarity coronal hole. Solar wind speed seems to have reached its maximum early in the reporting period with speeds at that time fluctuating around 550 km/s which have since decreased to current values around 490 km/s. The total magnetic field restored to fairly nominal values of 6nT just after the start of the reporting period and remained stable. Bz was variable in that range. Geomagnetic conditions were quiet to unsettled (both NOAA Kp and local K Dourbes 1-3). With the expected further decline of the high speed stream influence and nominal magnetic field strengths, geomagnetic conditions are expected to remain at quiet to unsettled levels.

Today's estimated international sunspot number (ISN): 042, based on 16 stations.

Solar indices for 19 May 2015

Wolf number Catania	///
10cm solar flux	110
AK Chambon La Forêt	016
AK Wingst	016
Estimated Ap	017
Estimated international sunspot number	056 - Based on 22 stations

Noticeable events summary

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

All times in UTC

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