Viewing archive of Friday, 4 May 2018

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 2018 May 04 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 124 Issued at 2200Z on 04 May 2018

IA. Analysis of Solar Active Regions and Activity from 03-2100Z to 04-2100Z

Solar activity has been at very low levels for the past 24 hours. There is currently 1 numbered sunspot region on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be very low with a slight chance for a C-class flare on days one, two, and three (05 May, 06 May, 07 May).
IIA. Geophysical Activity Summary 03-2100Z to 04-2100Z
The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed reached a peak of 440 km/s at 04/0641Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 643 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet levels on day one (05 May), quiet to minor storm levels on day two (06 May) and unsettled to minor storm levels on day three (07 May).
III. Event Probabilities 05 May to 07 May
Class M01%01%01%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       04 May 068
  Predicted   05 May-07 May 068/068/069
  90 Day Mean        04 May 070

V. Geomagnetic A Indices
  Observed Afr/Ap 03 May  003/003
  Estimated     Afr/Ap 04 May  005/005
  Predicted    Afr/Ap 05 May-07 May  006/005-017/022-014/020

VI. Geomagnetic Activity Probabilities 05 May to 07 May
A. Middle Latitudes
Minor storm01%30%25%
Major-severe storm01%05%05%
B. High Latitudes
Minor storm15%25%30%
Major-severe storm15%55%55%

All times in UTC

<< Go to daily overview page


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-flare2024/05/29X1.4
Last M-flare2024/05/30M1.0
Last geomagnetic storm2024/05/17Kp6 (G2)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
April 2024136.5 +31.6
May 2024146.7 +10.2
Last 30 days146.7 +8.6

This day in history*

Solar flares
*since 1994

Social networks