Viewing archive of Sunday, 21 April 2013

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2013 Apr 21 1248 UTC

SIDC Forecast

Valid from 1230 UTC, 21 Apr 2013 until 23 Apr 2013
Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

10cm fluxAp
21 Apr 2013107003
22 Apr 2013108006
23 Apr 2013106007

Bulletin

Seven sunspot groups were reported by Catania today. During past 24 hours fifteen low C-class flares were reported and they all originated from the Catania sunspot group 51 (NOAA AR 1726). This fast growing sunspot group has at the moment beta-gama configuration of its photosperic magnetic field and we expect that it will produce more C-class flares and also possibly M-class flares. The interplanetary magnetic field magnitude is about 7 nT. The Earth is currently under the influence of a slow solar wind with the speed of about 270 km/s. The low-latitude coronal hole in the southern hemisphere has reached the central meridian and we expect arrival of the fast solar wind late on April 24. We expect quiet to possibly active geomagnetic conditions in the next 48 hours.

Today's estimated international sunspot number (ISN): 061, based on 08 stations.

Solar indices for 20 Apr 2013

Wolf number Catania///
10cm solar flux105
AK Chambon La Forêt007
AK Wingst003
Estimated Ap003
Estimated international sunspot number059 - Based on 24 stations

Noticeable events summary

DayBeginMaxEndLocStrengthOP10cmRadio burst typesCatania/NOAA
None

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

All times in UTC

<< Go to daily overview page

Latest news

Support SpaceWeatherLive.com!

A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!

Donate SpaceWeatherLive Pro
Support SpaceWeatherLive with our merchandise
Check out our merchandise

Latest alerts

Get instant alerts!

Space weather facts

Last X-flare2025/03/28X1.1
Last M-flare2025/04/01M2.4
Last geomagnetic storm2025/03/27Kp5 (G1)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
February 2025154.6 +17.6
Last 30 days128.1 -22.5

This day in history*

Solar flares
12001X28.5
22001X2.01
32001X1.59
42014M9.35
52017M8.22
DstG
11960-272G3
21973-173G3
32001-101G1
41976-101G1
51994-96G3
*since 1994

Social networks