Viewing archive of Monday, 9 April 2001

Solar activity report

Report of Solar-Geophysical Activity 2001 Apr 09 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 099 Issued at 2200Z on 09 Apr 2001

IA. Analysis of Solar Active Regions and Activity from 08-2100Z to 09-2100Z

Solar activity increased to high levels. Region 9415 (S22W07) produced an M7/2B flare at 09/1534 UTC associated with a 1600 SFU Tenflare, Type II and IV radio sweeps, and a full-halo CME. Region 9415 remained a large, magnetically complex group with a strong, persistent magnetic delta configuration within the large leader spot. The remaining regions were simply-structured and showed no significant changes. New Region 9425 (S25W26) was numbered.
IB. Solar Activity Forecast
Solar activity is expected to be at moderate to high levels. Region 9415 could produce another major flare during the period.
IIA. Geophysical Activity Summary 08-2100Z to 09-2100Z
Geomagnetic field activity ranged from quiet to minor storm levels as CME effects gradually subsided. The greater than 10 MeV proton flux began to rise after today's major flare and was gradually increasing as the period ended. A greater than 100 MeV proton flux enhancement also followed the flare, but did not reach event levels.
IIB. Geophysical Activity Forecast
Geomagnetic field activity is expected to decrease to quiet to unsettled levels on 10 April. The CME associated with today's flare is expected to reach Earth during the early hours of 11 April. Active to major storm levels will be possible during 11 - 12 April as the CME passes Earth. The greater than 10 MeV proton flux may increase to event levels early on 10 April.
III. Event Probabilities 10 Apr to 12 Apr
Class M80%80%80%
Class X25%25%25%
IV. Penticton 10.7 cm Flux
  Observed       09 Apr 165
  Predicted   10 Apr-12 Apr  165/160/160
  90 Day Mean        09 Apr 167
V. Geomagnetic A Indices
  Observed Afr/Ap 08 Apr  033/041
  Estimated     Afr/Ap 09 Apr  018/025
  Predicted    Afr/Ap 10 Apr-12 Apr  012/015-030/035-025/025
VI. Geomagnetic Activity Probabilities 10 Apr to 12 Apr
A. Middle Latitudes
Minor storm10%30%20%
Major-severe storm05%25%05%
B. High Latitudes
Minor storm15%35%15%
Major-severe storm05%20%10%

<< 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!


Latest alerts

Get instant alerts!

Space weather facts

Last X-flare:2017/09/10X8.2
Last M-flare:2017/10/20M1.0
Last geomagnetic storm:2019/09/28Kp5 (G1)
Number of spotless days in 2019:216
Current stretch spotless days:18

This day in history*

Solar flares
*since 1994

Social networks