Viewing archive of Friday, 21 September 2007

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 2007 Sep 21 2203 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 264 Issued at 2200Z on 21 Sep 2007

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

Solar activity was very low. The visible disk remained spotless.
IB. Solar Activity Forecast
Solar activity is expected to remain very low.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was unsettled at the beginning of the period but quickly subsided to quiet levels. Real-time solar wind observations from ACE show a gradual increase in wind speed consistent with the onset of a coronal hole-high speed stream. However, Bz has been mostly northwards resulting in very little geomagnetic response at this time.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to become unsettled to active on 22-23 September, with a chance for minor storm periods at high latitudes, as the influence of the coronal hole increases. Activity is expected to subside to unsettled levels on 24 September.
III. Event Probabilities 22 Sep to 24 Sep
Class M01%01%01%
Class X01%01%01%
Proton01%01%01%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       21 Sep 067
  Predicted   22 Sep-24 Sep  067/067/067
  90 Day Mean        21 Sep 070
V. Geomagnetic A Indices
  Observed Afr/Ap 20 Sep  006/010
  Estimated     Afr/Ap 21 Sep  008/008
  Predicted    Afr/Ap 22 Sep-24 Sep  015/015-015/015-010/010
VI. Geomagnetic Activity Probabilities 22 Sep to 24 Sep
A. Middle Latitudes
Active35%35%15%
Minor storm10%10%10%
Major-severe storm10%10%05%
B. High Latitudes
Active35%30%25%
Minor storm15%15%10%
Major-severe storm10%10%05%

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