Viewing archive of Friday, 21 January 2005

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 2005 Jan 21 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 021 Issued at 2200Z on 21 Jan 2005

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

Solar activity was moderate. There were two M-class events during the past 24 hours: an M1 from Region 720 (N13W83) at 1016 UTC, and an M1 from Region 719 (S06W90) at 1355 UTC. Two new regions emerged on the disk today: Region 725 (S04W36) and Region 726 (S02E27).
IB. Solar Activity Forecast
Solar activity is expected to be moderate. In addition, there is a fair chance for a major flare and/or proton producing event from Region 720 as it rotates off the solar disk.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was initially at quiet to unsettled levels until a sudden impulse occurred at 1711 UTC. The sudden impulse was preceded by a strong shock at the ACE spacecraft: solar wind velocity jumped from about 600 km/s to 900-1000 km/s. The sudden impulse at Earth was followed by magnetopause crossings at geosynchronous orbit and severe levels of geomagnetic activity. The shock and subsequent disturbed solar wind were most likely a response to a CME associated with yesterday's X7 event. The greater than 100 MeV proton event that began at 20/0650 UTC continued to decline during the past 24 hours and dropped below threshold at 21/1845 UTC. The greater than 10 MeV proton event that began 16/0210 continues in progress: flux levels continue to decline with current levels at about 50 PFU.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at minor to major storm levels for the next 12-24 hours (22 January) as the current disturbance persists. Conditions should subside to mostly active levels by day two (23 January). Unsettled to active levels are expected to prevail on the third day (24 January) due to effects from a favorably positioned coronal hole.
III. Event Probabilities 22 Jan to 24 Jan
Class M90%80%70%
Class X30%20%10%
PCAFin progress
IV. Penticton 10.7 cm Flux
  Observed       21 Jan 114
  Predicted   22 Jan-24 Jan  105/095/090
  90 Day Mean        21 Jan 108
V. Geomagnetic A Indices
  Observed Afr/Ap 20 Jan  010/012
  Estimated     Afr/Ap 21 Jan  045/070
  Predicted    Afr/Ap 22 Jan-24 Jan  030/060-020/025-015/015
VI. Geomagnetic Activity Probabilities 22 Jan to 24 Jan
A. Middle Latitudes
Minor storm35%25%20%
Major-severe storm30%05%05%
B. High Latitudes
Minor storm25%30%30%
Major-severe storm55%25%05%

All times in UTC

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