Viewing archive of Friday, 15 April 2011

Solar activity report

Report of Solar-Geophysical Activity 2011 Apr 15 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 105 Issued at 2200Z on 15 Apr 2011

IA. Analysis of Solar Active Regions and Activity from 14-2100Z to 15-2100Z

Solar activity increased to moderate levels. Region 1190 (N13W26) produced an M1/1F flare at 15/1712Z. Associated with this event were discrete radio emissions ranging from 4995 MHz - 15400 MHz. Occasional C-class flares were also observed during the period. Region 1190 and Region 1193 (N17E44) remain the most significant regions. Both Regions 1190 and 1193 showed increases in areal coverage. A filament was observed lifting at 14/2324Z on GOES SXI. A CME was observed on SOHO/LASCO C2 imagery at 15/0036Z, with a speed of approximately 390 km/s. STEREO imagery showed the CME is expected to be geoeffective.
IB. Solar Activity Forecast
Solar activity is expected to be at low levels, with C-class flares expected for the next three days (16-18 April). There is also a slight chance for M-class flares during the period.
IIA. Geophysical Activity Summary 14-2100Z to 15-2100Z
The geomagnetic field was at quiet levels. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be predominantly quiet for the next three days (16-18 April).
III. Event Probabilities 16 Apr to 18 Apr
Class M55%55%55%
Class X05%05%05%
IV. Penticton 10.7 cm Flux
  Observed       15 Apr 129
  Predicted   16 Apr-18 Apr  135/140/145
  90 Day Mean        15 Apr 103
V. Geomagnetic A Indices
  Observed Afr/Ap 14 Apr  003/007
  Estimated     Afr/Ap 15 Apr  003/005
  Predicted    Afr/Ap 16 Apr-18 Apr  005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 16 Apr to 18 Apr
A. Middle Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%

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