Viewing archive of Saturday, 21 August 2004
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 2004 Aug 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 234 Issued at 2200Z on 21 Aug 2004IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity was very low. Occasional brightness
fluctuations were noted, but no flare activity occurred. Region 661
(N07W33) contains minor magnetic complexity and white light area
coverage of over 450 millionths, but has been stable for the past 48
hours. Region 663 (N11E52) has rotated fully into view as an
elongated beta spot group with some minor magnetic mixing. Region
664 (S10E25) exhibited considerable growth this period and also
displays some minor mixing. No new regions were numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be very
low to low. Isolated C-class flares are possible.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to active with isolated minor storm
periods. The disturbed periods are due to a slightly elevated solar
wind speed (near 500 km/s) and predominantly southward IMF Bz.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be quiet to active with isolated minor storm periods.
III. Event Probabilities 22 Aug to 24 Aug
| Class M | 15% | 15% | 15% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Aug 120 Predicted 22 Aug-24 Aug 120/120/120 90 Day Mean 21 Aug 109
V. Geomagnetic A Indices
Observed Afr/Ap 20 Aug 009/014 Estimated Afr/Ap 21 Aug 020/020 Predicted Afr/Ap 22 Aug-24 Aug 015/015-012/015-012/015
VI. Geomagnetic Activity Probabilities 22 Aug to 24 Aug
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 30% | 25% | 25% |
| Minor storm | 10% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 40% | 40% | 40% |
| Minor storm | 15% | 10% | 10% |
| Major-severe storm | 05% | 01% | 01% |
All times in UTC
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