Viewing archive of Tuesday, 18 September 2012
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 2012 Sep 18 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 262 Issued at 2200Z on 18 Sep 2012IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z
Solar activity has been at low levels for the past 24
hours. New Region 1575 (N07E75) was responsible for the only C-class
event today, which was a C1 x-ray event at 1009Z. This region was
also responsible for the two C-class events observed yesterday. When
Region 1575 rotated onto the visible disk, it had a beta magnetic
classification. No Earth directed CMEs were detected in the past 24
hours.
IB. Solar Activity Forecast
Solar activity is expected to be at
low levels with a slight chance for M-class events for the next
three days (19-21 September).
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
The geomagnetic field has been at quiet to unsettled levels for the
past 24 hours. Solar wind speeds, as measured by the ACE spacecraft,
indicated nominal background speeds with sustained periods of the
negative Bz component of the IMF.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to remain at quiet to unsettled levels for the next two
days (19-20 September). A slight increase to quiet to unsettled
levels with chance for active periods is expected on day three (21
September) as a coronal hole high speed stream moves into a
geoeffective position.
III. Event Probabilities 19 Sep to 21 Sep
| Class M | 10% | 10% | 10% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 18 Sep 104 Predicted 19 Sep-21 Sep 105/110/110 90 Day Mean 18 Sep 122
V. Geomagnetic A Indices
Observed Afr/Ap 17 Sep 006/004 Estimated Afr/Ap 18 Sep 009/009 Predicted Afr/Ap 19 Sep-21 Sep 008/010-009/010-008/012
VI. Geomagnetic Activity Probabilities 19 Sep to 21 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 25% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 20% |
| Minor storm | 30% | 30% | 30% |
| Major-severe storm | 25% | 25% | 30% |
All times in UTC
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