Viewing archive of Friday, 20 September 2013

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2013 Sep 20 1202 UTC

SIDC Forecast

Solar flares

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

Geomagnetism

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

Solar protons

Quiet

	10cm flux	Ap
20 Sep 2013	109	010
21 Sep 2013	113	007
22 Sep 2013	115	014

Bulletin

There are currently nine numbered sunspot groups on the solar disc, and three of them have beta configuration of the photospheric magnetic field. Three low C-class level flares were reported during last 24 hours and all originated from the same NOAA AR 1850, which just turned from behind the east solar limb. We expect more flaring activity at the C-class level. The M-class flares are possible but not very probable. The solar wind speed is about 480 km/s and slowly decreasing, and the interplanetary magnetic field magnitude is stable amounting about 3 nT. The geomagnetic conditions are at the moment quiet. We expect quiet to active geomagnetic conditions in the following 48 hours due to the arrival of a fast flow (in the morning of September 22), associated with the low-latitude coronal hole in the northern hemisphere.

Today's estimated international sunspot number (ISN): 062, based on 12 stations.

Solar indices for 19 Sep 2013

Wolf number Catania	094
10cm solar flux	108
AK Chambon La Forêt	019
AK Wingst	012
Estimated Ap	013
Estimated international sunspot number	044 - Based on 19 stations

Noticeable events summary

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

All times in UTC

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