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 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 365 Issued at 2200Z on 31 Dec 2011IA. 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 M | 40% | 40% | 40% |
| Class X | 05% | 05% | 05% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
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 | |||
|---|---|---|---|
| Active | 10% | 10% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 15% |
| Minor storm | 15% | 15% | 15% |
| Major-severe storm | 15% | 15% | 15% |
All times in UTC
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