Viewing archive of Wednesday, 11 August 2004

Solar activity report

Report of Solar-Geophysical Activity 2004 Aug 11 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 224 Issued at 2200Z on 11 Aug 2004

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

Solar activity was low. Today's activity consisted of numerous C-class flares, predominantly from Region 656 (S13E03). The largest event of the day was a C7/Sf from 656 at 1141 UTC. Region 656 continues to grow and is nearly 1000 millionths in area. The group continues to have a magnetic delta classification. A slow, faint CME was seen in LASCO off the south limb yesterday, beginning at about 10/1854 UTC in C2 imagery. The CME was associated with surge activity and a subsequent EIT wave that was observed just north of 656 and east of central meridian.
IB. Solar Activity Forecast
Solar activity is expected to be low to moderate. C-flares should continue and there is a good chance for an isolated M-class event during the next three days. There is also a slight chance for a major flare event from 656. Background levels are expected to increase tomorrow with the return of old Region 652 (N07, Carrington = 347).
IIA. Geophysical Activity Summary 10-2100Z to 11-2100Z
The geomagnetic field ranged from quiet to active levels. Solar wind data show the continuing influence of a high-speed coronal hole wind stream. The greater than 2 MeV electron fluxes reached high levels during the past 24 hours.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be generally unsettled with a chance for isolated active periods for the next two days (12-13 August). Conditions are expected to be unsettled to active on the 3rd day (14 August) with the arrival of weak transient flow from yesterday's CME.
III. Event Probabilities 12 Aug to 14 Aug
Class M55%55%55%
Class X10%10%10%
IV. Penticton 10.7 cm Flux
  Observed       11 Aug 131
  Predicted   12 Aug-14 Aug  140/145/150
  90 Day Mean        11 Aug 107
V. Geomagnetic A Indices
  Observed Afr/Ap 10 Aug  012/014
  Estimated     Afr/Ap 11 Aug  012/013
  Predicted    Afr/Ap 12 Aug-14 Aug  010/010-010/010-015/012
VI. Geomagnetic Activity Probabilities 12 Aug to 14 Aug
A. Middle Latitudes
Minor storm15%15%20%
Major-severe storm05%05%05%
B. High Latitudes
Minor storm15%15%20%
Major-severe storm05%05%05%

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