Viewing archive of Tuesday, 31 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 31 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 151 Issued at 2200Z on 31 May 2011

IA. Analysis of Solar Active Regions and Activity from 30-2100Z to 31-2100Z

Solar activity has been low. Region 1226 (S22E27) and Region 1227 (S18E39) each produced C1 x-ray events in the past 24 hours. Region 1226 was classified as a Dhc group with Beta magnetic characteristics while Region 1227 was a Dsi group with more complex Beta-Gamma characteristics. Region 1228 (N17E50) rapidly evolved into a Cso type group as new trailing spots emerged. New Region 1230 (N19E58) was numbered today. This new region, and the remainng regions, were generally quiescent, small and magnetically simple.
IB. Solar Activity Forecast
Solar activity is expected to be low, with a slight chance for M-class events for the next three days (1 - 3 Jun).
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
The geomagnetic field ranged from quiet to active levels over the past 24 hours. Heliospheric imagery from STEREO-B suggests the increased activity was the result of a transient, weak CME. 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 unsettled to active on day 1 (01 Jun) , quiet to unsettled on day 2 (02 Jun), and unsettled to active on day 3 (03 Jun). ENLIL model output indicates the passage of the 29 May CME early on day 1. A brief return to generally quiet conditions on day 2 is followed by disturbed conditions on day 3 as a recurrent coronal hole high speed stream begins to influence the magnetosphere.
III. Event Probabilities 01 Jun to 03 Jun
Class M20%20%20%
Class X01%01%01%
Proton01%01%01%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       31 May 112
  Predicted   01 Jun-03 Jun  115/115/110
  90 Day Mean        31 May 108
V. Geomagnetic A Indices
  Observed Afr/Ap 30 May  007/009
  Estimated     Afr/Ap 31 May  010/012
  Predicted    Afr/Ap 01 Jun-03 Jun  010/010-007/008-010/010
VI. Geomagnetic Activity Probabilities 01 Jun to 03 Jun
A. Middle Latitudes
Active20%10%20%
Minor storm10%05%10%
Major-severe storm05%01%05%
B. High Latitudes
Active20%15%20%
Minor storm25%10%20%
Major-severe storm10%05%15%

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