Viewing archive of Wednesday, 17 April 2002

Solar activity report

Report of Solar-Geophysical Activity 2002 Apr 17 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 107 Issued at 2200Z on 17 Apr 2002

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

Solar activity was moderate. Region 9906 (S14W41) produced a long-duration M2/2n flare at 17/0824 UTC. This flare was associated with a 3000 sfu radio burst at 2695 MHz, Type II/IV radio sweeps, and an Earth-directed "halo" CME visible in LASCO images. The region appears to have retained its size and complexity following the flare. Eruptive limb activity (EPL, BSL, and flare) in the vicinity of Region 9905 (S15W90) occurred during and after the LDE event in 9906.
IB. Solar Activity Forecast
Solar activity is expected to be moderate. Additional M-class flares, possibly including a major flare, are expected in Region 9906.
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
The geomagnetic field ranged from quiet to major storm levels. A shock was observed at the NASA ACE spacecraft at 17/1022 UTC and was followed by an SI at ground magnetometers at 17/1109 UTC (57 nT at Boulder). This shock is believed to be associated with the LDE M1/CME which occurred on 15 April. A greater than 10 MeV proton event began at 17/1530 UTC. The maximum flux observed so far was 24 pfu at 17/1540 UTC. This event is believed to be associated with the LDE M2 discussed in Part IA.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at active to minor storm levels as the current disturbance recovers over the next 24 hours. Another disturbance at minor to major storm levels is expected to begin on 19 April in response to the LDE M2/CME which occurred on 17 April. The greater than 10 MeV proton event currently in progress is expected to end within the next 24 hours.
III. Event Probabilities 18 Apr to 20 Apr
Class M75%60%50%
Class X10%10%05%
IV. Penticton 10.7 cm Flux
  Observed       17 Apr 194
  Predicted   18 Apr-20 Apr  190/185/180
  90 Day Mean        17 Apr 201
V. Geomagnetic A Indices
  Observed Afr/Ap 16 Apr  005/010
  Estimated     Afr/Ap 17 Apr  035/055
  Predicted    Afr/Ap 18 Apr-20 Apr  020/020-040/040-020/030
VI. Geomagnetic Activity Probabilities 18 Apr to 20 Apr
A. Middle Latitudes
Minor storm20%30%20%
Major-severe storm10%20%10%
B. High Latitudes
Minor storm25%50%25%
Major-severe storm15%30%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 2020:42
Current stretch spotless days:28

This day in history*

Solar flares
*since 1994

Social networks