Viewing archive of Friday, 18 December 2009
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 2009 Dec 18 2201 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 352 Issued at 2200Z on 18 Dec 2009IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z Solar activity has been low. One C-class event
occurred from Region 1035 (N30W45). It was an optically
uncorrelated, impulsive C7.6 observed at 18/1855Z. Numerous B-class
events were also observed throughout the period. Region 1035
continues to grow in area (310 millionths), longitudinal extent (12
degrees) and spot count (14 spots). However, during the past 24
hours, the large negative polarity penumbra and associated umbra
located near region center decayed resulting in a beta magnetic
configuration for the region.
IB. Solar Activity Forecast
Solar activity is expected to be low.
There is a slight chance for an isolated M-class event from Region
1035.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
The geomagnetic field has been quiet.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be quiet for day one (19 December) of the forecast
period. An increase to unsettled to active levels is expected on
day two (20 December). The increase in activity levels is due to
the expected arrival of the CME observed on 16 December. By day
three (21 December), the field will return to mostly quiet levels.
III. Event Probabilities 19 Dec to 21 Dec
| Class M | 10% | 10% | 10% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 18 Dec 084 Predicted 19 Dec-21 Dec 085/085/083 90 Day Mean 18 Dec 073
V. Geomagnetic A Indices
Observed Afr/Ap 17 Dec 002/001 Estimated Afr/Ap 18 Dec 002/005 Predicted Afr/Ap 19 Dec-21 Dec 005/005-015/015-007/007
VI. Geomagnetic Activity Probabilities 19 Dec to 21 Dec
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 45% | 15% |
| Minor storm | 05% | 15% | 05% |
| Major-severe storm | 01% | 05% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 50% | 20% |
| Minor storm | 10% | 20% | 10% |
| Major-severe storm | 01% | 10% | 01% |
All times in UTC
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