Viewing archive of Saturday, 27 August 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 Aug 27 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 239 Issued at 2200Z on 27 Aug 2011IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z Solar activity has been at very low levels for the past
24 hours. There are currently 9 numbered regions on the visible
disk, but only 5 regions have retained their spots. All spotted
regions seem to be either stable or in a decay phase. The largest
flare of the period was a B8 x-ray event, observed at 0446Z, from
Region 1275 (N07W08). A CME was observed in LASCO C2 and STEREO
Behind COR2 imagery. Analysis indicates that the CME is a backsided
event.
IB. Solar Activity Forecast
Solar activity is expected to be at
very low levels with a chance for C-class events for the next three
days (28-30 August). Even though Region 1271 (N16W82) is expected to
rotate off the visible disk in the next 24 hours, it appears old
Region 1267 (S18, L=246) is rotating onto the east limb.
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
The geomagnetic field has been at quiet levels for the past 24 hours.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be at quiet to unsettled levels with a chance for active
periods at high latitudes for the next two days (28-29 August), as a
coronal hole high speed stream (CH HSS) moves into a geoeffective
position. Predominantly quiet levels are expected on day three (30
August), as the effects of the CH HSS wane.
III. Event Probabilities 28 Aug to 30 Aug
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 27 Aug 104 Predicted 28 Aug-30 Aug 100/098/095 90 Day Mean 27 Aug 097
V. Geomagnetic A Indices
Observed Afr/Ap 26 Aug 003/003 Estimated Afr/Ap 27 Aug 003/005 Predicted Afr/Ap 28 Aug-30 Aug 008/008-008/008-005/005
VI. Geomagnetic Activity Probabilities 28 Aug to 30 Aug
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 20% | 15% |
| Minor storm | 05% | 05% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 30% | 25% | 15% |
| Minor storm | 15% | 10% | 01% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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