Viewing archive of Monday, 4 September 2017

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2017 Sep 04 1230 UTC

SIDC Forecast

Valid from 1230 UTC, 04 Sep 2017 until 06 Sep 2017
Solar flares

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

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Quiet

10cm fluxAp
04 Sep 2017115008
05 Sep 2017115007
06 Sep 2017115007

Bulletin

Solar flaring activity reached moderate levels with an M1.2 flare originating from Catania group 46 (NOAA region 2673) peaking at 05:49UT. This region grew very fast over the last 24 hours and has developed significant complexity with mixed polarity in the intermediate spots. Meanwhile, Catania group 47 (NOAA region 2674) seems to have become less active but remains large and with significant flaring potential. Flaring is expected to continue to occur from both regions with especially Catania group 46 contributing to a significant probability for M flaring. Overall we estimate that C flaring will occur over the next 24 hours and that there is a very significant chance for M flares (45%). No Earth directed CMEs have been observed in coronagraph data. Solar Proton flux levels are at background values and are expected to remain so.

Solar wind speed continued a slow overall decline from around 500 km/s to around 470 km/s. Total magnetic field was in the nominal 3-6nT range with Bz variable and the phi angle mostly in the positive sector. Solar wind is expected to further recover to nominal conditions over the next days. Geomagnetic conditions were quiet to active (local K Dourbes 1-3, NOAA Kp 2-4) and are expected to remain quiet to unsettled over the next days.

Today's estimated international sunspot number (ISN): 120, based on 17 stations.

Solar indices for 03 Sep 2017

Wolf number Catania///
10cm solar flux120
AK Chambon La Forêt015
AK Wingst010
Estimated Ap009
Estimated international sunspot number118 - Based on 28 stations

Noticeable events summary

DayBeginMaxEndLocStrengthOP10cmCatania/NOAARadio burst types
04053605490605S10W04M1.21F46/2673

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