Viewing archive of Sunday, 16 September 2012

Solar activity report

Report of Solar-Geophysical Activity 2012 Sep 16 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 260 Issued at 2200Z on 16 Sep 2012

IA. Analysis of Solar Active Regions and Activity from 15-2100Z to 16-2100Z

Solar activity was very low. New Region 1573 (N17E62 - Axx/alpha) produced occasional B-class flares as it rotated into view. Region 1566 (N23W89 - Hrx/alpha) produced a B-class flare as it approached the west limb. Region 1569 (S12W13 - Cso/beta) showed gradual spot and penumbral decay in its intermediate and trailer portions. New Region 1574 (S25W15 - Bxo/beta), a small reverse-polarity group, was also numbered. No Earth-directed CME activity occurred during the period.
IB. Solar Activity Forecast
Solar activity is expected to be very low through the period (17 - 19 September) with a chance for a C-class flare.
IIA. Geophysical Activity Summary 15-2100Z to 16-2100Z
Geomagnetic field activity was at quiet to unsettled levels. An increase to unsettled levels occurred late in the period associated with the onset of a solar sector boundary crossing (SSBC). Intermittent periods of weakly-southward IMF Bz along with minor increases in solar wind speeds and IMF Bt were associated with the SSBC.
IIB. Geophysical Activity Forecast
Geomagnetic field activity is expected to remain at quiet to unsettled levels on day 1 (17 September) due to minor changes in the solar wind. A decrease to quiet levels is expected on day 2 (18 September). Activity is expected to increase to quiet to unsettled levels on day 3 (19 September), with a slight chance for active levels, as a coronal hole high-speed stream begins to disturb the field.
III. Event Probabilities 17 Sep to 19 Sep
Class M10%10%10%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       16 Sep 097
  Predicted   17 Sep-19 Sep  095/095/100
  90 Day Mean        16 Sep 122
V. Geomagnetic A Indices
  Observed Afr/Ap 15 Sep  005/006
  Estimated     Afr/Ap 16 Sep  006/008
  Predicted    Afr/Ap 17 Sep-19 Sep  007/010-006/005-007/008
VI. Geomagnetic Activity Probabilities 17 Sep to 19 Sep
A. Middle Latitudes
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm20%15%25%
Major-severe storm10%05%15%

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