Viewing archive of Wednesday, 31 August 2005

Solar activity report

Report of Solar-Geophysical Activity 2005 Aug 31 2204 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 243 Issued at 2200Z on 31 Aug 2005

IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z

Solar activity was at low levels. Region 803 (N11W13) produced a long duration C2 x-ray event that occurred at 31/1151Z. This event was followed by a full halo CME that was first observed at 31/1100Z by LASCO imagery. Region 803 continues to show decay and is down to 20 millionths of sunspot area. Region 806 (S17E23) was limited to B-class flare activity and has shown slight decay in sunspot coverage. The magnetic gamma structure remains intact although it has weakened since yesterday. No new regions were numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be at very low to low levels.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
The geomagnetic field was at quiet to minor storm levels. The elevated conditions ensued following a sustained southward Bz (ranging between -10 and -20 nT) which began just after 31/1000Z. This activity is believed to be in response to a corotating interaction region. 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 be at quiet to minor storm levels. A coronal hole may keep conditions elevated throughout the period. Isolated major storm conditions may be possible on 2 September due to the effects of the full halo CME from the long duration C2 x-ray event that occurred today.
III. Event Probabilities 01 Sep to 03 Sep
Class M15%15%15%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       31 Aug 084
  Predicted   01 Sep-03 Sep  080/080/080
  90 Day Mean        31 Aug 094
V. Geomagnetic A Indices
  Observed Afr/Ap 30 Aug  003/004
  Estimated     Afr/Ap 31 Aug  018/032
  Predicted    Afr/Ap 01 Sep-03 Sep  015/020-025/030-020/025
VI. Geomagnetic Activity Probabilities 01 Sep to 03 Sep
A. Middle Latitudes
Minor storm15%25%20%
Major-severe storm05%15%10%
B. High Latitudes
Minor storm20%30%25%
Major-severe storm10%20%15%

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