Viewing archive of Friday, 4 May 2018

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2018 May 04 1230 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

Minor storm expected (A>=30 or K=5)

Solar protons

Quiet

	10cm flux	Ap
04 May 2018	067	007
05 May 2018	068	007
06 May 2018	069	007

Bulletin

Solar activity was very low with X ray flux remaining below B level. Two small spotted regions developed on disk. A bipolar group in the South Eastern quadrant (Catania number 80 with Zurich Class B) and a small unipolar group (Catania number 79 with Zurich Class A) near the central meridian. X ray flux is expected to remain at background levels.

A partial halo CME is visible in SoHO/LASCO C2 coronagraph images from around 17:12UT, on May 3. It is directed towards the East and has an angular extent of about 180 degrees (CACTus software underestimated the angular extent). STEREO A coronagraph images show the CME as Eastbound from the STEREO A perspective while the EUVI 195 images onboard STEREO display the on disk signatures of the CME initiation also in the Eastern hemisphere (from STEREO A perspective). All this evidence confirms that this is a far side CME which will not have any impact on Earth. No other CMEs have been detected in coronagraph data.

The solar proton flux levels are at background values and are expected to remain so.

The solar wind is in a slow wind regime. Solar wind speed is roughly at 350 km/s with total magnetic field 1.5-4.5nT. The magnetic field phi angle indicates connection to a positive magnetic field sector.

Nominal Solar wind conditions are expected over the next 24 hours, then followed by a sector boundary crossing and co-rotating interaction region in front of the coronal hole high speed stream expected on May 6.

Geomagnetic conditions were quiet (local K Dourbes 0-2 and NOAA Kp 1-2) and are expected to remain quiet in the next 24 hours. Geomagnetic conditions will afterwards rise to active and likely minor storm conditions due to the expected coronal hole high speed stream preceeded by a co-rotating interaction region.

Today's estimated international sunspot number (ISN): 012, based on 17 stations.

Solar indices for 03 May 2018

Wolf number Catania	///
10cm solar flux	067
AK Chambon La Forêt	007
AK Wingst	004
Estimated Ap	003
Estimated international sunspot number	000 - Based on 37 stations

Noticeable events summary

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

All times in UTC

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