Viewing archive of Saturday, 1 October 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 Oct 01 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 274 Issued at 2200Z on 01 Oct 2011

IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 01-2100Z

Solar activity has been moderate. Region 1305 (N12W12) produced an M1/1n flare at 01/0959Z associated with an Earth-directed CME. The CME became visible in STEREO imagery at 01/1109Z and has an estimated speed of 500 km/s. Region 1302 (N16W41) produced a Sf optical flare immediately before the M1 flare at 01/0917Z. The two events were associated with a pair of Type II Sweeps (620 km/s at 01/0906Z and 850 km/s at 01/0955Z), a Type IV Sweep and a 180 sfu Tenflare. Region 1305 has grown slightly in area and spot number and has a beta-gamma magnetic configuration. Region 1302 maintains an area of 700 millionths and a beta-gamma-delta magnetic configuration.
IB. Solar Activity Forecast
Solar activity is expected to be low to moderate with a slight chance for an X-class event from Regions 1302 and 1305 for the next three days (02-04 October).
IIA. Geophysical Activity Summary 30-2100Z to 01-2100Z
The geomagnetic field was quiet to unsettled with isolated active periods from 01/0000-0600Z as measured by the Boulder magnetometer. The activity was a result of multiple solar sector boundary crossings. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet to unsettled on day one (02 October) due to effects from the coronal hole high speed stream and possible effects from the CME observed on 29 September. Mostly quiet conditions are expected on day two (03 October). Quiet to unsettled conditions with a chance for active and isolated minor storm periods are expected on day three (04 October) due to a combination of the CMEs observed on 30 September and 01 October. The two CMEs are due to arrive early and late on day three, respectively.
III. Event Probabilities 02 Oct to 04 Oct
Class M70%70%70%
Class X20%20%20%
Proton15%15%15%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       01 Oct 137
  Predicted   02 Oct-04 Oct  140/140/140
  90 Day Mean        01 Oct 111
V. Geomagnetic A Indices
  Observed Afr/Ap 30 Sep  005/008
  Estimated     Afr/Ap 01 Oct  012/012
  Predicted    Afr/Ap 02 Oct-04 Oct  008/008-005/005-015/015
VI. Geomagnetic Activity Probabilities 02 Oct to 04 Oct
A. Middle Latitudes
Active20%10%45%
Minor storm10%01%25%
Major-severe storm01%01%05%
B. High Latitudes
Active20%15%45%
Minor storm10%01%25%
Major-severe storm01%01%10%

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