Viewing archive of Thursday, 13 December 2001

Solar activity report

Report of Solar-Geophysical Activity 2001 Dec 13 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 347 Issued at 2200Z on 13 Dec 2001

IA. Analysis of Solar Active Regions and Activity from 12-2100Z to 13-2100Z

Solar activity was high. Region 9733 (N14E04) produced an X6.2/3b flare at 13/1430 UTC. This event also produced associated Type II and IV radio sweeps and a partial-halo coronal mass ejection (CME). This region is continuing to grow more complex, developing a near horizontal inversion line in its trailing portions. Region 9727 (S21W66) was also quite active during the period, producing three M-class flares. Region 9727 showed continued growth in size and complexity during the period. Regions 9727 and 9733 both retain beta-gamma-delta magnetic classifications. Three new spot groups were numbered today: 9739 (S13W02), 9740 (S06E56), and 9741 (N07E72).
IB. Solar Activity Forecast
Solar activity is expected to be at moderate to high levels with isolated M-class flares likely. There will also be a chance for a major flare from Regions 9727 or 9733.
IIA. Geophysical Activity Summary 12-2100Z to 13-2100Z
The geomagnetic field was at mostly quiet levels, with an isolated unsettled period at 12/21-2400 UTC.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to unsettled conditions on the first day of the forecast period. The CME produced by the X6.2 flare should impact earth late on the second day. The impact is expected to produce active conditions on the second and third days. Imagery from the LASCO/SOHO spacecraft show that most of the CME is directed in a predominately Northerly direction, hence the expected effect on Earth should be significantly less than if the CME was more directly aimed toward Earth.
III. Event Probabilities 14 Dec to 16 Dec
Class M80%80%70%
Class X20%20%15%
IV. Penticton 10.7 cm Flux
  Observed       13 Dec 220
  Predicted   14 Dec-16 Dec  220/220/210
  90 Day Mean        13 Dec 218
V. Geomagnetic A Indices
  Observed Afr/Ap 12 Dec  008/012
  Estimated     Afr/Ap 13 Dec  006/007
  Predicted    Afr/Ap 14 Dec-16 Dec  012/015-020/020-025/025
VI. Geomagnetic Activity Probabilities 14 Dec to 16 Dec
A. Middle Latitudes
Minor storm10%20%25%
Major-severe storm01%10%15%
B. High Latitudes
Minor storm15%25%30%
Major-severe storm05%10%10%

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