Viewing archive of Sunday, 17 September 2017

Solar activity report

Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 2017 Sep 17 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 260 Issued at 2200Z on 17 Sep 2017

IA. Analysis of Solar Active Regions and Activity from 16-2100Z to 17-2100Z

Solar activity has been at very low levels for the past 24 hours. There are currently 1 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be very low on days one, two, and three (18 Sep, 19 Sep, 20 Sep).
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 779 km/s at 17/0251Z. Total IMF reached 7 nT at 17/2057Z. The maximum southward component of Bz reached -5 nT at 17/1157Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 46263 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to active levels on days one and two (18 Sep, 19 Sep) and quiet to unsettled levels on day three (20 Sep).
III. Event Probabilities 18 Sep to 20 Sep
Class M01%01%01%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       17 Sep 072
  Predicted   18 Sep-20 Sep 075/075/075
  90 Day Mean        17 Sep 081

V. Geomagnetic A Indices
  Observed Afr/Ap 16 Sep  023/030
  Estimated     Afr/Ap 17 Sep  014/020
  Predicted    Afr/Ap 18 Sep-20 Sep  012/015-011/012-009/010

VI. Geomagnetic Activity Probabilities 18 Sep to 20 Sep
A. Middle Latitudes
Minor storm10%10%05%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm25%30%25%
Major-severe storm40%40%30%

All times in UTC

<< Go to daily overview page

Latest news


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!

Support SpaceWeatherLive with our merchandise
Check out our merchandise

Latest alerts

Get instant alerts!

Space weather facts

Last X-flare2024/07/16X2
Last M-flare2024/07/22M1.5
Last geomagnetic storm2024/06/28Kp8- (G4)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
June 2024164.2 -7.5
July 2024186.6 +22.4
Last 30 days180.1 +31.1

This day in history*

Solar flares
*since 1994

Social networks