Viewing archive of Thursday, 21 April 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 Apr 21 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 111 Issued at 2200Z on 21 Apr 2011

IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z

Solar Activity has been at low levels for the past 24 hours. Region 1195 (S17E43) has been the most active region producing multiple C-class events, the largest being a C8/Sf at 21/0948Z. Region 1193 (N16W32) remains magnetically complex, but has yet to produce any notable activity. Region 1197 (S16E57) was numbered early in the period and has remained stable and quiet.
IB. Solar Activity Forecast
Solar activity is expected to be at low levels with a slight chance for M-class activity for the next three days (22-24 April).
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field has been at quiet levels for the past 24 hours. The effects of the latest coronal hole high-speed stream continue to wane. Solar wind speeds, as measured by the ACE spacecraft, have decreased from 500 - 440 km/s.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at mostly quiet levels for the next three days (22-24 April).
III. Event Probabilities 22 Apr to 24 Apr
Class M20%20%20%
Class X01%01%01%
Proton01%01%01%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       21 Apr 113
  Predicted   22 Apr-24 Apr  115/115/115
  90 Day Mean        21 Apr 105
V. Geomagnetic A Indices
  Observed Afr/Ap 20 Apr  011/016
  Estimated     Afr/Ap 21 Apr  005/005
  Predicted    Afr/Ap 22 Apr-24 Apr  008/008-005/005-005/005
VI. Geomagnetic Activity Probabilities 22 Apr to 24 Apr
A. Middle Latitudes
Active15%05%05%
Minor storm01%01%01%
Major-severe storm01%01%01%
B. High Latitudes
Active20%05%05%
Minor storm05%01%01%
Major-severe storm01%01%01%

All times in UTC

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