Viewing archive of Tuesday, 21 June 2011
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 2011 Jun 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 172 Issued at 2200Z on 21 Jun 2011IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity was low. Todays activity consisted of a
long-duration C7 X-ray event which began at 0122Z, reached maximum
at 0325Z and ended at 0427Z. The X-ray event was associated with a
Sf flare from Region 1236 (N17W21) as well as the eruption of a 17
degree filament near N39W01. Also associated with this activity was
a symmetric halo CME which first entered the SOHO C2 coronagraph
field of view at 0316Z and had an estimated plane of sky speed of
about 640 km/s. Region 1236 was generally unchanged during the past
24 hours and is the dominant spot group on the disk. The other
spotted regions were very small and appeared to be decaying.
IB. Solar Activity Forecast
Solar activity is expected to be low
for the next three days.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to unsettled during the past 24
hours. Solar wind observations from the ACE spacecraft indicate a
solar sector boundary crossing between 1200 and 1500Z (positive to
negative).
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be quiet for the next 36-42 hours. An increase is
expected beginning sometime late on day 2 (23 June) and continuing
through day 3 (24 June). Geomagnetic activity is expected to be
mostly active during this time period, with a chance for minor storm
periods at mid-latitudes, and minor to major storm periods at high
latitudes. The increase in activity is forecast due to expected
combined effects from todays halo CME event and a favorably
positioned coronal hole.
III. Event Probabilities 22 Jun to 24 Jun
| Class M | 05% | 05% | 05% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Jun 095 Predicted 22 Jun-24 Jun 095/095/095 90 Day Mean 21 Jun 104
V. Geomagnetic A Indices
Observed Afr/Ap 20 Jun 007/007 Estimated Afr/Ap 21 Jun 007/008 Predicted Afr/Ap 22 Jun-24 Jun 005/005-018/018-025/035
VI. Geomagnetic Activity Probabilities 22 Jun to 24 Jun
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 05% | 25% | 30% |
| Minor storm | 01% | 30% | 30% |
| Major-severe storm | 01% | 15% | 20% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 05% | 20% | 25% |
| Minor storm | 01% | 35% | 35% |
| Major-severe storm | 01% | 25% | 30% |
All times in UTC
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