Viewing archive of Wednesday, 28 May 2003

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 2003 May 28 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 148 Issued at 2200Z on 28 May 2003

IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z

Solar activity increased to high levels today. Region 365 (S07W32) produced two X-class flares early in the period. The first was an X1.3/2b flare that occurred at 27/2307Z with an associated Tenflare (910 sfu), Type IV, and Type II (estimated shock velocity of 607 km/s.) radio sweep. The second, larger flare, an X3.6 x-ray event which occurred at 28/0027Z that also had an associated Tenflare (1600 sfu), Type IV, and Type II (estimated 392 km/s.) radio sweep. Both flares had associated CME's (based on LASCO imagery) that appear to be Earth directed. This region continues to show good growth and remains a beta-gamma-delta magnetic complex. Little activity was noted from the rest of the disk. Region 374 (S22W59) was newly assigned today.
IB. Solar Activity Forecast
Solar activity is expected to be at moderate to high levels. Region 365 is very capable of producing major flare activity.
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
The geomagnetic field was at active to major storm levels. A recurrent high speed stream coronal hole is responsible for the elevated levels. The greater than 10 MeV proton fluxes have been just under event threshold levels for the past several hours of this period. The greater than 2 MeV electron fluxes at geosynchronous orbit reached moderate levels today.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at predominantly active to minor storm levels through the forecast period. Transient activity from today's X-flares is expected by day two of the interval with resulting major to severe storm conditions possible. The greater than 10 MeV proton fluxes at geosynchronous orbit may reach threshold levels on day one of the period.
III. Event Probabilities 29 May to 31 May
Class M75%75%75%
Class X25%25%25%
IV. Penticton 10.7 cm Flux
  Observed       28 May 130
  Predicted   29 May-31 May  135/140/135
  90 Day Mean        28 May 125
V. Geomagnetic A Indices
  Observed Afr/Ap 27 May  018/026
  Estimated     Afr/Ap 28 May  025/038
  Predicted    Afr/Ap 29 May-31 May  025/025-040/050-015/025
VI. Geomagnetic Activity Probabilities 29 May to 31 May
A. Middle Latitudes
Minor storm25%35%20%
Major-severe storm15%25%10%
B. High Latitudes
Minor storm30%35%30%
Major-severe storm20%35%20%

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