Viewing archive of Friday, 12 April 2013

Solar activity report

Report of Solar-Geophysical Activity 2013 Apr 12 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 102 Issued at 2200Z on 12 Apr 2013

IA. Analysis of Solar Active Regions and Activity from 11-2100Z to 12-2100Z

Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M3 event observed at 12/2038Z from Region 1718 (N21W46). There are currently 6 numbered sunspot regions on the disk.
IB. Solar Activity Forecast
Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days one, two, and three (13 Apr, 14 Apr, 15 Apr).
IIA. Geophysical Activity Summary 11-2100Z to 12-2100Z
The geomagnetic field has been at quiet levels for the past 24 hours. Solar wind speed, as measured by the ACE spacecraft, reached a peak speed of 525 km/s at 12/0311Z. Total IMF reached 5 nT at 12/0713Z. The maximum southward component of Bz reached -4 nT at 11/2125Z. Protons greater than 10 MeV at geosynchronous orbit reached a peak level of 65 pfu at 11/2120Z. Electrons greater than 2 MeV at geosynchronous orbit reached a peak level of 274 pfu.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to major storm levels on day one (13 Apr), unsettled to major storm levels on day two (14 Apr) and quiet levels on day three (15 Apr). Protons have a chance of crossing threshold on day one (13 Apr) and have a slight chance of crossing threshold on days two and three (14 Apr, 15 Apr).
III. Event Probabilities 13 Apr to 15 Apr
Class M50%50%50%
Class X15%15%15%
IV. Penticton 10.7 cm Flux
  Observed       12 Apr 138
  Predicted   13 Apr-15 Apr 135/130/120
  90 Day Mean        12 Apr 113

V. Geomagnetic A Indices
  Observed Afr/Ap 11 Apr  004/004
  Estimated     Afr/Ap 12 Apr  005/005
  Predicted    Afr/Ap 13 Apr-15 Apr  018/026-028/045-007/008

VI. Geomagnetic Activity Probabilities 13 Apr to 15 Apr
A. Middle Latitudes
Minor storm35%45%05%
Major-severe storm10%15%01%
B. High Latitudes
Minor storm20%25%20%
Major-severe storm60%35%20%

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