Viewing archive of Tuesday, 17 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 17 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 137 Issued at 2200Z on 17 May 2011IA. Analysis of Solar Active Regions and Activity from 16-2100Z to 17-2100Z Solar activity was very low during the past 24 hours.
Regions 1208 (N09W78) and 1214 (S24W24) produced several B-class
events. All other regions on the disk remained relatively quiet and
stable. A filament erupted near N13W07 and an associated CME became
visible on STEREO COR2 imagery at 17/0709Z. The CME was well above
the ecliptic plane and is not expected to be geoeffective.
IB. Solar Activity Forecast
Solar activity is expected to be very
low with a chance for C-class activity for the next three days
(18-20 May).
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
The geomagnetic field was mostly quiet during the past 24 hours.
Solar wind velocities gradually decreased from approximately 620
km/s to 540 km/s indicating the effects from the coronal hole
high-speed stream (CH HSS) that has been influencing the field for
the past few days are beginning to subside.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to be mostly quiet for the next three days (18-20 May).
III. Event Probabilities 18 May to 20 May
| Class M | 01% | 01% | 01% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 17 May 092 Predicted 18 May-20 May 092/095/095 90 Day Mean 17 May 109
V. Geomagnetic A Indices
Observed Afr/Ap 16 May 010/012 Estimated Afr/Ap 17 May 008/008 Predicted Afr/Ap 18 May-20 May 005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 18 May to 20 May
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 05% | 05% |
| Minor storm | 01% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 05% | 05% |
| Minor storm | 01% | 01% | 01% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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