Viewing archive of Tuesday, 20 January 2004

Solar activity report

Report of Solar-Geophysical Activity 2004 Jan 20 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 020 Issued at 2200Z on 20 Jan 2004

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

Solar activity was high. Region 540 (S14W22) produced an M6/2n flare at 20/0743Z. Radio bursts associated with this flare included a 4500 sfu burst on 245 MHz and Type II sweep with a shock speed of 950 km/s. A CME was visible on LASCO imagery. Region 540 also produced an impressive long duration C5 flare that occurred between 19/2202Z through 20/0229Z, peaking at 20/0045Z. A full halo CME was observed with this event. Soon after the eruption in Region 540, segments of the large circular filament in the northwest quadrant also erupted. Region 540 maintains a weak delta configuration in its trailing spots, but further decay in total area was also noted. The trailing spots in Region 542 (N10W03) have been identified as a separate region and were numbered as Region 544.
IB. Solar Activity Forecast
Solar activity is expected to be low to moderate. Though in decay, Region 540 still maintains potential for isolated M-class flares. The remaining three spot groups on the visible disk have potential for C-class activity.
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
The geomagnetic field was quiet to active. Solar wind speed is in gradual decline as a large transequatorial coronal hole rotates out of a geoeffective position. Solar wind speed decreased to near 500 km/s, but periods of southward Bz generated occasional active periods. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels again today.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to range from quiet to major storming over the next three days. Quiet to active periods are expected on 21 January. The full halo CME observed on LASCO imagery at 20/0006Z will likely impact the geomagnetic field early on 22 January. Active to major storm periods are possible. Unsettled to active conditions are expected on January 23 as the storm subsides.
III. Event Probabilities 21 Jan to 23 Jan
Class M30%30%30%
Class X05%05%05%
IV. Penticton 10.7 cm Flux
  Observed       20 Jan 129
  Predicted   21 Jan-23 Jan  130/130/130
  90 Day Mean        20 Jan 138
V. Geomagnetic A Indices
  Observed Afr/Ap 19 Jan  010/017
  Estimated     Afr/Ap 20 Jan  018/022
  Predicted    Afr/Ap 21 Jan-23 Jan  012/015-035/045-015/025
VI. Geomagnetic Activity Probabilities 21 Jan to 23 Jan
A. Middle Latitudes
Minor storm10%25%15%
Major-severe storm05%15%05%
B. High Latitudes
Minor storm15%35%20%
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!


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 2020:72
Last spotless day:2020/03/30

This day in history*

Solar flares
*since 1994

Social networks