Viewing archive of Saturday, 18 August 2012

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 2012 Aug 18 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 231 Issued at 2200Z on 18 Aug 2012

IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z

Solar activity was high. Region 1548 (N19E86) produced an M5/Sf flare at 18/0102Z, accompanied by a Tenflare (150 pfu). An M1/Sn flare from the same region followed at 18/0323Z, also accompanied by a Tenflare (120 pfu). Finally, an M2/1N occurred at 18/1607Z. Several coronal mass ejections (CMEs) were observed in the past 24 hours, none appear to have a geoeffective component. SDO 304 imagery showed a filament eruption in the vicinity of Region 1543 (N23W74) around 17/16Z. A CME was subsequently observed in LASCO C2 coronagraph imagery at 17/1836Z, and in LASCO C3 imagery at 17/1918Z. A second filament eruption and CME was observed near Region 1543 between 17/22Z and 18/0034Z. It was visible in STEREO-B COR2 imagery at 18/0110Z and in LASCO C3 imagery at 18/0454Z. This CME was directed well north of the ecliptic.
IB. Solar Activity Forecast
Solar activity is expected to be low with moderate activity likely for the next three days (19-21 August).
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
The geomagnetic field was quiet to active. Solar wind speed at the ACE spacecraft ranged between about 350-420 km/s during the period. The Bz component of the interplanetary magnetic field ranged between -8 and +12 nT. Solar wind density at ACE increased sharply after 18/19Z. The geomagnetic field reached active levels during the last period (18-21Z) coincident with a change to the positive sector and the arrival of the corotating active region.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet to unsettled for the next three days (19-21 August) as a corotating interaction region and coronal hole high speed stream become geoeffective.
III. Event Probabilities 19 Aug to 21 Aug
Class M55%55%55%
Class X05%05%05%
Proton01%01%01%
PCAFGreen
IV. Penticton 10.7 cm Flux
  Observed       18 Aug 097
  Predicted   19 Aug-21 Aug  100/100/100
  90 Day Mean        18 Aug 125
V. Geomagnetic A Indices
  Observed Afr/Ap 17 Aug  011/011
  Estimated     Afr/Ap 18 Aug  009/011
  Predicted    Afr/Ap 19 Aug-21 Aug  010/012-011/012-007/008
VI. Geomagnetic Activity Probabilities 19 Aug to 21 Aug
A. Middle Latitudes
Active20%20%10%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active20%20%15%
Minor storm30%30%20%
Major-severe storm25%25%15%

All times in UTC

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