Viewing archive of Tuesday, 21 February 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Feb 21 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
21 Feb 2017	083	006
22 Feb 2017	085	014
23 Feb 2017	085	031

Bulletin

Several B flares were released from NOAA region 2638 (Catania groups 95 and 96) with the strongest a B7.5 flare peaking at 14:25UT. This region remains the most complex on disk while Catania group 93 (NOAA 2636) decayed and also Catania group 94 (NOAA 2637) appears in decay. C flaring from Catania groups 95/96 (NOAA 2638) is quite possible but not expected. A prominence eruption at the NE limb was visible in SDO/AIA 304A around 17:00UT causing only a very narrow CME as seen in SoHO/LASCO coronagraph data. No Earth directed CMEs have been observed in coronagraph data. Proton fluxes were at background values and are expected to remain so.

Solar wind speed further declined to 450 km/s while the total magnetic field remained around the nominal 5nT with Bz variable. Solar wind conditions will continue at nominal levels but should become enhanced again on February 23 due to high speed stream from the equatorial part of the positive polarity coronal hole. Geomagnetic conditions were quiet to active (NOAA Kp 1-3, local K Dourbes 0-4). Quiet to unsettled conditions are expected over the next 24 hours with later an increase to active conditions or possibly minor geomagnetic storm levels due to the expected high speed stream.

Today's estimated international sunspot number (ISN): 028, based on 11 stations.

Solar indices for 20 Feb 2017

Wolf number Catania	047
10cm solar flux	081
AK Chambon La Forêt	020
AK Wingst	011
Estimated Ap	010
Estimated international sunspot number	033 - Based on 23 stations

Noticeable events summary

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

All times in UTC

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