Viewing archive of Sunday, 16 April 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Apr 16 1237 UTC

SIDC Forecast

Valid from 1230 UTC, 16 Apr 2017 until 18 Apr 2017
Solar flares

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

Geomagnetism

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

Solar protons

Quiet

10cm fluxAp
16 Apr 2017073010
17 Apr 2017072015
18 Apr 2017071007

Bulletin

Solar activity was at very low levels. No flares were observed during the reporting period. No Earth-directed CMEs were observed in available coronagraph imagery. Integral proton flux for protons with energies above 10 MeV remained at background level. Solar activity is expected to grow till B-class flaring level today (April 16) and till C-class flaring level from tomorrow (April 17) due to anticipated return of previously active regions to the visible solar disk.

Solar wind speed decreased from about 350 km/s to values around 315 km/s (05UT, 16 April), but then increased again till 350 km/s. The total interplanetary magnetic field (IMF) strength, as recorded by the DSCOVR satellite, was around 5 nT. Bz fluctuated between -4.5 and +4 nT. Quiet geomagnetic conditions (K Dourbes between 0 and 2; NOAA Kp between 1 and 2) were registered in the past 24 hours. Solar wind speed is expected to grow further today due to the arrival of high speed stream from the positive polarity coronal hole. In response geomagnetic conditions are likely to experience mostly quiet to unsettled conditions from late today (16 April) and tomorrow (17 April). Isolated episodes of active geomagnetic conditions are also possible.

Today's estimated international sunspot number (ISN): 000, based on 21 stations.

Solar indices for 15 Apr 2017

Wolf number Catania///
10cm solar flux073
AK Chambon La Forêt008
AK Wingst010
Estimated Ap008
Estimated international sunspot number000 - Based on 20 stations

Noticeable events summary

DayBeginMaxEndLocStrengthOP10cmCatania/NOAARadio burst types
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-flare2025/04/01M2.5
Last geomagnetic storm2025/03/27Kp5 (G1)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
February 2025154.6 +17.6
April 2025152.5 -2.1
Last 30 days130.7 -17.9

This day in history*

Solar flares
12001X1.77
22017M8.35
31999M6.2
42001M3.57
52017M1.81
DstG
11979-168G4
21960-151G3
31992-105G2
42004-104G2
51994-103G3
*since 1994

Social networks