Viewing archive of Wednesday, 18 December 2013

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2013 Dec 18 1234 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
18 Dec 2013	160	003
19 Dec 2013	160	006
20 Dec 2013	160	013

Bulletin

The strongest solar flare reported during the past 24 hours was a C4.0 flare (peaked at 23:29 UTC, on December 17). The flare seems to originate from Catania sunspot region 91 (no NOAA number yet) located on the east solar limb. New Catania sunspot group 87 (NOAA AR 1928) shows some activity at the same moment. NOAA AR 1928 is growing and currently also has the beta-gamma magnetic configuration of its photospheric field (just like sunspot region 80 or NOAA AR 1917). The probability for C-flares is around 80%, M-flares around 30%, with Catania sunspot regions 80, 87 and 91 as main source candidates. The chances for an X-flare are low. No Earth- directed CMEs were observed. Solar wind conditions are stable with a solar wind speed of 400 km/s and a magnitude of the interplanetary magnetic field of 5 nT (observed by ACE). Geomagnetic conditions are quiet (K<3). A glancing blow of the CME of December 16 might lead to unsettled or at most active conditions at the end of December 19 (UTC time).

Today's estimated international sunspot number (ISN): 097, based on 08 stations.

Solar indices for 17 Dec 2013

Wolf number Catania	150
10cm solar flux	159
AK Chambon La Forêt	008
AK Wingst	005
Estimated Ap	004
Estimated international sunspot number	091 - Based on 14 stations

Noticeable events summary

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

All times in UTC

<< Go to daily overview page