Viewing archive of Saturday, 20 October 2012

Solar activity report

Report of Solar-Geophysical Activity 2012 Oct 20 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 294 Issued at 2200Z on 20 Oct 2012

IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z

Solar activity was high. An impulsive M9 flare occurred at 20/1814Z from newly numbered Region 1598 (S15E82). This region appeared to be responsible for several C-class flares as it approached the visible disk and will continue to be the area of interest for the next few days. An associated Type II radio sweep was recorded with an estimated speed of 516 km/s. Region 1593 (N15E09) showed some shearing and spot loss over the past 24 hours, while Region 1597 (S22W58) had some intermediate spot growth and separation between leader and follower. The remaining regions showed little to or no changes. No Earth-directed CMEs were observed for the past 24 hours.
IB. Solar Activity Forecast
Solar activity is expected to be low for the next three days (21-23 October) with a chance for isolated M-class flares.
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
The geomagnetic field was quiet over the past 24 hours. Solar wind speed, as measured at the ACE spacecraft, steadily decreased from approximately 440 km/s to near 380 km/s. The Bz component of the interplanetary magnetic field continued to show minor deflections of +/- 2 nT while total fields hovered near 4 nT. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels throughout the period.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet on day 1 (21 October). An increase to quiet to unsettled levels is expected for days 2 and 3 (22-23 October) due to the effects of a weak coronal hole high speed stream.
III. Event Probabilities 21 Oct to 23 Oct
Class M40%40%40%
Class X10%10%10%
IV. Penticton 10.7 cm Flux
  Observed       20 Oct 151
  Predicted   21 Oct-23 Oct  150/150/145
  90 Day Mean        20 Oct 120
V. Geomagnetic A Indices
  Observed Afr/Ap 19 Oct  003/002
  Estimated     Afr/Ap 20 Oct  003/004
  Predicted    Afr/Ap 21 Oct-23 Oct  006/005-007/008-007/008
VI. Geomagnetic Activity Probabilities 21 Oct to 23 Oct
A. Middle Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm20%25%25%
Major-severe storm10%15%15%

<< 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!


Space weather facts

Last X-flare:2017/09/10X8.2
Last M-flare:2017/10/20M1.0
Last geomagnetic storm:2020/02/19Kp5 (G1)
Number of spotless days in 2020:76
Current stretch spotless days:5

This day in history*

Solar flares
*since 1994

Social networks