Viewing archive of Sunday, 17 April 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 Apr 17 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 107 Issued at 2200Z on 17 Apr 2011IA. Analysis of Solar Active Regions and Activity from 16-2100Z to 17-2100Z Solar activity remained at low levels. Region 1185
(N14, L=032) produced four C-class flares as it rotated off of the
solar limb. Region 1193 (N16E19) continues to increase in areal
coverage and maintains its beta-gamma magnetic configuration. Region
1190 (N14W53) showed decreases in both spot number and areal
coverage, however, it retains its beta-gamma magnetic configuration.
IB. Solar Activity Forecast
Solar activity is expected to be at
low levels, with C-class flares expected for the next three days
(18-20). There remains a chance for M-class flares during the
period.
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
The geomagnetic field was at quiet levels.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be at predominantly quiet levels on days one and two
(18-19 April). Activity is expected to increase to quiet to
unsettled levels on day three (20 April), with a chance for active
levels as well as a slight chance for minor storm levels at high
latitudes. The increase in activity is due to a coronal hole
high-speed stream.
III. Event Probabilities 18 Apr to 20 Apr
| Class M | 40% | 40% | 40% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 17 Apr 114 Predicted 18 Apr-20 Apr 115/112/110 90 Day Mean 17 Apr 103
V. Geomagnetic A Indices
Observed Afr/Ap 16 Apr 002/004 Estimated Afr/Ap 17 Apr 003/005 Predicted Afr/Ap 18 Apr-20 Apr 005/005-005/005-010/010
VI. Geomagnetic Activity Probabilities 18 Apr to 20 Apr
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 05% | 05% | 35% |
| Minor storm | 01% | 01% | 10% |
| Major-severe storm | 01% | 01% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 40% |
| Minor storm | 01% | 01% | 15% |
| Major-severe storm | 01% | 01% | 05% |
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