Viewing archive of Sunday, 17 April 2005

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 2005 Apr 17 2210 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA, #Space Environment Center and the U.S. Air Force. #

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 107 Issued at 2200Z on 17 Apr 2005

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

Solar activity has been low. Newly numbered Region 755 (S11E76) generated three C-class events on 17 Apr, two near 1300Z and one at 2054Z. All other regions remain steady.
IB. Solar Activity Forecast
Solar activity is expected to be low. Region 755 has the continued potential to produce C-class activity.
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
The geomagnetic field has been at quiet to unsettled levels. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to unsettled levels. There's a chance for isolated periods of active levels as a high-speed stream from a small, but well defined coronal hole rotates into potentially geoeffective range from 19 - 20 Apr.
III. Event Probabilities 18 Apr to 20 Apr
Class M10%15%15%
Class X01%01%01%
Proton01%01%01%
PCAFgreen
IV. Penticton 10.7 cm Flux
  Observed       17 Apr 084
  Predicted   18 Apr-20 Apr  090/090/090
  90 Day Mean        17 Apr 093
V. Geomagnetic A Indices
  Observed Afr/Ap 16 Apr  004/007
  Estimated     Afr/Ap 17 Apr  005/006
  Predicted    Afr/Ap 18 Apr-20 Apr  005/008-010/012-008/012
VI. Geomagnetic Activity Probabilities 18 Apr to 20 Apr
A. Middle Latitudes
Active15%20%20%
Minor storm01%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active20%25%25%
Minor storm05%10%10%
Major-severe storm02%05%05%

All times in UTC

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