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 UTC
Prepared 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 2011

IA. 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 M01%01%01%
Class X01%01%01%
Proton01%01%01%
PCAFgreen
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
Active10%05%05%
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Active15%05%05%
Minor storm01%01%01%
Major-severe storm01%01%01%

All times in UTC

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