Viewing archive of Wednesday, 17 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 17 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 229 Issued at 2200Z on 17 Aug 2011

IA. Analysis of Solar Active Regions and Activity from 16-2100Z to 17-2100Z

Solar activity was low. Both Regions 1271 (N16E50) and 1272 (S19E55) produced C-class events during the summary period. The largest was a C3 from Region 1271 at 17/1119Z. Region 1271 ended the period as an Esi type spot group with beta-gamma-delta magnetic characteristics. New Region 1273 (S18W03) was numbered today and classified as a Bxo type spot group with simple beta magnetic characteristics. A CME from Region 1272 was observed in SOHO/LASCO C2 imagery at 17/0248Z with a plane-of-sky speed of about 550 km/s. This CME is not expected to be geoeffective.
IB. Solar Activity Forecast
Solar activity is expected to be low. Continued C-class events are expected from Regions 1271 and 1272, There is a slight chance for an M-class event given the increasing size and complexity of Region 1271.
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
The geomagnetic field was quiet to unsettled. Wind speed at the ACE spacecraft continued to decline through the summary period, ending near 420 km/s.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be mostly quiet for the next three days (18-20 August).
III. Event Probabilities 18 Aug to 20 Aug
Class M15%15%15%
Class X01%05%05%
Proton01%01%01%
PCAFGreen
IV. Penticton 10.7 cm Flux
  Observed       17 Aug 098
  Predicted   18 Aug-20 Aug  098/100/100
  90 Day Mean        17 Aug 096
V. Geomagnetic A Indices
  Observed Afr/Ap 16 Aug  006/008
  Estimated     Afr/Ap 17 Aug  008/008
  Predicted    Afr/Ap 18 Aug-20 Aug  005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 18 Aug to 20 Aug
A. Middle Latitudes
Active10%05%10%
Minor storm01%01%05%
Major-severe storm00%00%05%
B. High Latitudes
Active20%05%20%
Minor storm05%05%05%
Major-severe storm05%01%05%

All times in UTC

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