Viewing archive of Sunday, 11 September 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 Sep 11 2222 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 254 Issued at 2200Z on 11 Sep 2005

IA. Analysis of Solar Active Regions and Activity from 10-2100Z to 11-2100Z

Solar activity was at high levels. Region 808 (S09E30) produced a long duration X2 major flare at 10/2211Z that had an associated Tenflare of 1600 sfu, a Type IV radio sweep, and a Type II radio sweep with an estimated shock velocity of 1606 km/sec. An associated asymmetrical Earth directed full halo CME was observed on LASCO imagery. Further significant activity included a long duration M3/1f flare that occurred at 11/1312Z. An M3 flare with an associated Type IV radio sweep that occurred at 11/0235Z, and an impulsive M1 flare that occurred at 10/2040Z. Region 808 has shown some fragmentation of the trailing portion of the spot cluster, however this spot group remains very dynamic and complex with the spot area exceeding 1200 millionths. Magnetic analysis continues to depict a very strong delta structure in the dominant central penumbral spot. No new regions were numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be at high levels. Region 808 is expected to continue to produce major flares.
IIA. Geophysical Activity Summary 10-2100Z to 11-2100Z
The geomagnetic field was at active to severe storm levels today. The storming periods are most likely due to the passage of a CME from the X6 flare that occurred on 09 September. The greater than 10 MeV proton event that began on 08/0215Z was further enhanced with today's shock passage, and reached a peak flux of 1880 pfu at 11/0425Z. The greater than 100 MeV proton that began at 08/0405Z, reached a peak flux of 8 pfu at 09/1920Z, and ended at 11/0545Z.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at active to major storm levels. Severe storm levels may be possible on 12 September due to the passage of the full halo CME from the X2 major flare that occurred on 10 September. Isolated severe storm conditions may be possible on 13 September due to the continued effects of the ongoing transient flow. Although it most likely will be negligible, a recurrent coronal hole should be geoeffective through the forecast period. The greater than 10 MeV proton event is expected to continue through 13 September.
III. Event Probabilities 12 Sep to 14 Sep
Class M90%85%80%
Class X75%70%65%
PCAFin progress
IV. Penticton 10.7 cm Flux
  Observed       11 Sep 110
  Predicted   12 Sep-14 Sep  110/110/110
  90 Day Mean        11 Sep 091
V. Geomagnetic A Indices
  Observed Afr/Ap 10 Sep  015/030
  Estimated     Afr/Ap 11 Sep  070/100
  Predicted    Afr/Ap 12 Sep-14 Sep  090/100-050/060-020/030
VI. Geomagnetic Activity Probabilities 12 Sep to 14 Sep
A. Middle Latitudes
Minor storm35%30%15%
Major-severe storm35%20%10%
B. High Latitudes
Minor storm40%35%20%
Major-severe storm35%25%15%

All times in UTC

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