Viewing archive of Saturday, 21 May 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 May 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 141 Issued at 2200Z on 21 May 2011IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity was very low. Four magnetically simple,
unipolar regions were observed on the visible disk, Region 1216
(S15E01) was the largest. New Region 1219 (N15E71) rotated on the
east limb and was numbered today.
IB. Solar Activity Forecast
Solar activity is expected to remain
very low to low. There is a slight chance of a C-class x-ray flare
during the next three days (22 May - 24 May).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet. Solar wind speed measured at the
ACE spacecraft increased to about 400 km/.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be quiet for the next three days (22 May - 24 May).
III. Event Probabilities 22 May to 24 May
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 May 084 Predicted 22 May-24 May 080/080/080 90 Day Mean 21 May 108
V. Geomagnetic A Indices
Observed Afr/Ap 20 May 002/003 Estimated Afr/Ap 21 May 005/005 Predicted Afr/Ap 22 May-24 May 005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 22 May to 24 May
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 30% | 15% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
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