Viewing archive of Sunday, 25 April 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 Apr 25 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 116 Issued at 2200Z on 25 Apr 2004
IA. Analysis of Solar Active Regions and Activity from 24-2100Z to 25-2100Z
Solar activity was moderate. Region 599 (N16E28)
produced an M2/1N flare today at 0537 UTC, as well as a number of
smaller, C-class events. The group continued to grow today, and
shows some magnetic complexity, particularly just behind the large
leader spot where smaller spots of opposite polarity are in close
proximity. Most of the flare brightenings occurred along an
east-west inversion line in the mid-to-trailing portion of the
region. Region 536 (S08W36) is still the largest group on the disk,
but was quiet and appears to be slowly decaying.
IB. Solar Activity Forecast
Solar activity is expected to be
mostly low, but there is a fair chance for an additional, isolated
M-class event during the next three days from Region 599.
IIA. Geophysical Activity Summary 24-2100Z to 25-2100Z
The geomagnetic field was mostly unsettled. There was an isolated
active period at high latitudes from 0600-0900 UTC. Solar wind data
show continuation of a weak, high-speed stream, with velocities
ranging mostly between 500-550 km/s.
IIB. Geophysical Activity Forecast
The geomagnetic field should
persist at the current, mostly unsettled levels for the next 24-36
hours (26 April to partway through 27 April). A decrease is expected
to begin partway through the 2nd day (27 April) and quiet to
unsettled levels should prevail on the third day (28 April).
III. Event Probabilities 26 Apr to 28 Apr
Class M | 35% | 35% | 35% |
Class X | 05% | 05% | 05% |
Proton | 05% | 05% | 05% |
PCAF | green
|
IV. Penticton 10.7 cm Flux
Observed 25 Apr 107
Predicted 26 Apr-28 Apr 110/110/110
90 Day Mean 25 Apr 107
V. Geomagnetic A Indices
Observed Afr/Ap 24 Apr 007/011
Estimated Afr/Ap 25 Apr 010/010
Predicted Afr/Ap 26 Apr-28 Apr 012/012-010/010-005/008
VI. Geomagnetic Activity Probabilities 26 Apr to 28 Apr
A. Middle Latitudes |
Active | 25% | 20% | 15% |
Minor storm | 20% | 15% | 10% |
Major-severe storm | 10% | 05% | 05% |
B. High Latitudes |
Active | 35% | 30% | 25% |
Minor storm | 25% | 20% | 15% |
Major-severe storm | 15% | 10% | 05% |
All times in UTC
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