Viewing archive of Saturday, 31 December 2011

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 2011 Dec 31 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 365 Issued at 2200Z on 31 Dec 2011

IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z

Solar activity was moderate. There were two M-class x-ray flares from Region 1389 (S23E31), the largest of which was a M2/Sf at 31/1315Z accompanied by a 150 pfu tenflare. The second was a M1/1F at 31/1626Z. This region was classified as an Ekc type group with beta-gamma characteristics. Region 1386 was also active, producing a C1/Sf flare at 31/1731Z. The remaining regions were stable.
IB. Solar Activity Forecast
Solar activity is expected to remain at predominantly low levels, with a chance for occasional M-class activity from Region 1389.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
The geomagnetic field was quiet. Solar wind speed at the ACE spacecraft was about 350 km/s and Bz was mostly neutral to slightly negative.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to reach unsettled levels for the next three days (1-3 January) as a recurrent coronal hole high speed stream becomes geoeffective. There is a slight chance for active conditions during this period.
III. Event Probabilities 01 Jan to 03 Jan
Class M40%40%40%
Class X05%05%05%
IV. Penticton 10.7 cm Flux
  Observed       31 Dec 133
  Predicted   01 Jan-03 Jan  135/135/135
  90 Day Mean        31 Dec 144
V. Geomagnetic A Indices
  Observed Afr/Ap 30 Dec  005/005
  Estimated     Afr/Ap 31 Dec  000/003
  Predicted    Afr/Ap 01 Jan-03 Jan  008/010-007/010-008/008
VI. Geomagnetic Activity Probabilities 01 Jan to 03 Jan
A. Middle Latitudes
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm15%15%15%
Major-severe storm15%15%15%

All times in UTC

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