Viewing archive of Wednesday, 28 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 28 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 362 Issued at 2200Z on 28 Dec 2011IA. Analysis of Solar Active Regions and Activity from 27-2100Z to 28-2100Z Solar activity has been at low levels for the past 24
hours. Region 1386 (S18E08), Region 1387 (S21W70) and New Region
1389 (S20E70) have all produced C-class events, the largest being
from Region 1389, which was a C7/1F flare at 1425Z. Region 1386 and
1387 both continue to grow and evolve, but have yet to produce
major solar activity. Several small non-Earth directed CMEs were
observed during the summary period.
IB. Solar Activity Forecast
Solar activity is expected to be at
low to moderate levels for the next three days (29 - 31 December).
IIA. Geophysical Activity Summary 27-2100Z to 28-2100Z
The geomagnetic field has been at quiet levels for the past 24 hours.
Signatures observed by the ACE spacecraft indicate the arrival of a
small CME around 0950Z. Solar wind speeds increased from around 250
km/s to 280 km/s with and increase in the total IMF to around 14 nT.
This transient appears to be from an unknown event, perhaps on 24
December. The lower energetic particle sensors on the ACE spacecraft
continue to gradually increase, indicating another approaching CME.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be at quiet to active levels with a chance for isolated
minor storm levels on day one (29 December) as multiple CMEs are
expected to arrive. Quiet to unsettled level are expected on day two
(30 December) as effects the previous CMEs wane. Predominantly
quiet levels are expected on day three (31 December).
III. Event Probabilities 29 Dec to 31 Dec
| Class M | 40% | 40% | 40% |
| Class X | 01% | 01% | 01% |
| Proton | 10% | 10% | 10% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 28 Dec 145 Predicted 29 Dec-31 Dec 145/140/140 90 Day Mean 28 Dec 144
V. Geomagnetic A Indices
Observed Afr/Ap 27 Dec 002/001 Estimated Afr/Ap 28 Dec 003/004 Predicted Afr/Ap 29 Dec-31 Dec 015/022-012/012-005/005
VI. Geomagnetic Activity Probabilities 29 Dec to 31 Dec
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 15% | 01% |
| Minor storm | 10% | 05% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 15% |
| Minor storm | 25% | 20% | 10% |
| Major-severe storm | 20% | 20% | 01% |
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