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 UTC
Prepared 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 2011

IA. 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 M05%05%05%
Class X01%01%01%
Proton01%01%01%
PCAFgreen
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
Active05%25%30%
Minor storm01%30%30%
Major-severe storm01%15%20%
B. High Latitudes
Active05%20%25%
Minor storm01%35%35%
Major-severe storm01%25%30%

All times in UTC

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