Viewing archive of Saturday, 29 September 2012

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 2012 Sep 29 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 273 Issued at 2200Z on 29 Sep 2012

IA. Analysis of Solar Active Regions and Activity from 28-2100Z to 29-2100Z

Solar activity was at low levels. Numerous weak C-class events were observed during the past 24 hours, mostly from Regions 1575 (N07W73) and 1577 (N09W54). New Region 1583 (N13W75) emerged on the disk as a simple bipolar group. No significant changes were observed from the remainder of the disk and limb. No Earth-directed CMEs were observed during the period.
IB. Solar Activity Forecast
Solar activity is expected to be at low levels with a slight chance for M-class activity all three days of the forecast period (30 September - 02 October).
IIA. Geophysical Activity Summary 28-2100Z to 29-2100Z
The geomagnetic field was at quiet levels. ACE satellite measurements indicated a steady decline in wind speed from about 325 km/s to near 275 km/s while the Bz component of the interplanetary magnetic field did not vary much beyond +/- 3 nT. At about 29/0100Z, a solar sector boundary crossing from a negative (toward) to a positive (away) orientation was observed.
IIB. Geophysical Activity Forecast
Geomagnetic field activity is expected to be at predominately quiet levels through about midday on day one (30 September). By late on day one, active levels with a chance for minor to major storm periods are expected due to the arrival of the Earth-directed CME observed early on 28 September. On day two (01 October), continued minor to major storm conditions are expected early in the day, decreasing to mostly quiet to unsettled levels with a chance for isolated active periods as effects from the CME wane. Predominately quiet to unsettled conditions are expected on day three (02 October).
III. Event Probabilities 30 Sep to 02 Oct
Class M10%10%10%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       29 Sep 136
  Predicted   30 Sep-02 Oct  135/130/125
  90 Day Mean        29 Sep 125
V. Geomagnetic A Indices
  Observed Afr/Ap 28 Sep  002/003
  Estimated     Afr/Ap 29 Sep  004/004
  Predicted    Afr/Ap 30 Sep-02 Oct  018/035-018/025-007/008
VI. Geomagnetic Activity Probabilities 30 Sep to 02 Oct
A. Middle Latitudes
Minor storm25%30%05%
Major-severe storm05%10%01%
B. High Latitudes
Minor storm25%20%20%
Major-severe storm60%70%20%

All times in UTC

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