Viewing archive of Sunday, 21 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 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 233 Issued at 2200Z on 21 Aug 2011IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity was very low to low. Region 1271
(N16W01) produced a C2/Sf event at 20/2258Z. Region 1272 (S21E03)
produced several B-class/Sf events in the past 24 hours followed by
a C1/Sf at 21/1840Z. Regions 1271 and 1272 showed significant growth
in trailer areas. Region 1275 (N06E68) was numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be low
with a slight chance for moderate activity.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to unsettled due to the arrival of a
favorably positioned negative polarity coronal hole.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be unsettled with a chance for active conditions at high
latitudes on Days 1 and 2 (22-23 Aug) with the arrival of a second
coronal hole high speed stream (HSS). Day 3 (24 Aug) is expected to
decrease to quiet conditions as effects from the HSS subside.
III. Event Probabilities 22 Aug to 24 Aug
| Class M | 20% | 20% | 20% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Aug 101 Predicted 22 Aug-24 Aug 103/105/105 90 Day Mean 21 Aug 096
V. Geomagnetic A Indices
Observed Afr/Ap 20 Aug 004/005 Estimated Afr/Ap 21 Aug 005/005 Predicted Afr/Ap 22 Aug-24 Aug 010/012-008/010-005/005
VI. Geomagnetic Activity Probabilities 22 Aug to 24 Aug
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 20% | 15% |
| Minor storm | 10% | 05% | 01% |
| Major-severe storm | 05% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 40% | 40% | 15% |
| Minor storm | 20% | 15% | 05% |
| Major-severe storm | 10% | 05% | 01% |
All times in UTC
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