Viewing archive of Tuesday, 18 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 18 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 018 Issued at 2200Z on 18 Jan 2005

IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z

Solar activity was moderate. Region 720 (N13W44) continued to flare; however, the largest event in the past 24 hours was an M4/2n at 18/1551 UTC. Although the region remains large and magnetically complex, further sunspot restructuring and decay is evident since yesterday. New Region 724 (S12W07) emerged on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be moderate to high. Region 720, although diminishing in complexity, still has sufficient potential for another major solar event.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
The geomagnetic field ranged from unsettled to severe storm levels. The greater than 10 MeV proton event remains in progress with a start time of 16/0210 UTC and a peak flux of 5040 pfu observed at 17/1750 UTC. The greater than 100 MeV proton event also remains in progress with a start time of 17/1215 UTC and a 28 pfu peak flux observed at 17/1700 UTC. GOES spacecraft electron sensors and ACE SWEPAM instruments remain affected by the energetic proton event.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to remain at active to severe storm levels for the next 24 to 48 hours. The arrival of the CME associated with the X3 flare on 17 January has not yet been observed but is expected to contribute to geomagnetic activity over the next 12 to 24 hours. The greater than 100 MeV proton event is expected to end by early on 19 January, barring a new major flare. The greater than 10 MeV proton event is expected to remain in progress through late 19 to early 20 January.
III. Event Probabilities 19 Jan to 21 Jan
Class M90%90%90%
Class X30%20%10%
PCAFin progress
IV. Penticton 10.7 cm Flux
  Observed       18 Jan 124
  Predicted   19 Jan-21 Jan  120/110/100
  90 Day Mean        18 Jan 107
V. Geomagnetic A Indices
  Observed Afr/Ap 17 Jan  027/063
  Estimated     Afr/Ap 18 Jan  040/080
  Predicted    Afr/Ap 19 Jan-21 Jan  030/075-020/030-015/020
VI. Geomagnetic Activity Probabilities 19 Jan to 21 Jan
A. Middle Latitudes
Minor storm60%50%20%
Major-severe storm10%05%05%
B. High Latitudes
Minor storm70%60%30%
Major-severe storm20%15%05%

<< 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!

Support SpaceWeatherLive with our merchandise
Check out our merchandise

Latest alerts

Get instant alerts!

Space weather facts

Last X-flare2024/02/22X6.3
Last M-flare2024/02/28M1.5
Last geomagnetic storm2024/03/03Kp6- (G2)
Spotless days
Last spotless day2022/06/08
Monthly mean Sunspot Number
January 2024123 +8.8

This day in history*

Solar flares
*since 1994

Social networks