Viewing archive of Friday, 17 December 2004

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 2004 Dec 17 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 352 Issued at 2200Z on 17 Dec 2004

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

Solar activity was very low. Region 710 (S07W72) has shown a slight increase in area and spot number, but remains quiet. New regions 712 (S10E50) and 713 (S10E70) were numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be very low to low. There is a chance for a C-class flare from the new regions near the southeast limb.
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
The geomagnetic field was at quiet to active levels with a period of minor storming between 17/0300Z and 17/0600Z. The active to minor storm levels were due to the continued influence of a geoeffective coronal hole high speed stream. There was an increase in the solar wind speed at ACE from approximately 550 km/s to 650 km/s during the reporting period.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be quiet to active with minor storm periods possible at high latitudes on 18 December. Expect quiet to unsettled with isolated active conditions on 19 December as the high speed coronal hole stream subsides. Expect quiet to unsettled levels on 20 December.
III. Event Probabilities 18 Dec to 20 Dec
Class M05%05%05%
Class X01%01%01%
IV. Penticton 10.7 cm Flux
  Observed       17 Dec 090
  Predicted   18 Dec-20 Dec  090/090/095
  90 Day Mean        17 Dec 104
V. Geomagnetic A Indices
  Observed Afr/Ap 16 Dec  008/010
  Estimated     Afr/Ap 17 Dec  014/020
  Predicted    Afr/Ap 18 Dec-20 Dec  008/015-006/008-004/005
VI. Geomagnetic Activity Probabilities 18 Dec to 20 Dec
A. Middle Latitudes
Minor storm10%10%05%
Major-severe storm01%01%01%
B. High Latitudes
Minor storm15%10%10%
Major-severe storm05%05%01%

All times in UTC

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