Viewing archive of Monday, 31 December 2001

Solar activity report

Report of Solar-Geophysical Activity 2001 Dec 31 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 365 Issued at 2200Z on 31 Dec 2001

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

Solar activity was at low levels. Region 9754 (S08W42) produced the largest flare of the period, an impulsive C6/1f flare at 31/1845 UTC. Region 9767 (S23E60) was the only other source of optically correlated flare activity during the period, producing small C-class flares. This region appears to have fully rotated onto the visible disk doubling reported arial spot coverage from yesterday's analysis. Other regions on the disk were mostly placid throughout the period.
IB. Solar Activity Forecast
Solar activity is expected to be at moderate levels. Regions 9767, 9754, and 9751 (S08W42) all have the potential to produce M-class flares.
IIA. Geophysical Activity Summary 30-2100Z to 31-2100Z
The geomagnetic field was at quiet to unsettled levels. The greater than 10 MeV proton event that began on 30/0245 UTC remains in progress and reached a maximum of 108 pfu at 31/1620 UTC.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at quiet to unsettled levels. A slight chance of active conditions exist on day one with the potential for a weak shock passage from the west limb CME of 29 December. The greater than 10 MeV event is expected to end late on day one of the forecast period.
III. Event Probabilities 01 Jan to 03 Jan
Class M75%75%75%
Class X15%15%15%
PCAFin progress
IV. Penticton 10.7 cm Flux
  Observed       31 Dec 246
  Predicted   01 Jan-03 Jan  245/240/240
  90 Day Mean        31 Dec 219
V. Geomagnetic A Indices
  Observed Afr/Ap 30 Dec  015/017
  Estimated     Afr/Ap 31 Dec  008/012
  Predicted    Afr/Ap 01 Jan-03 Jan  015/015-010/010-008/008
VI. Geomagnetic Activity Probabilities 01 Jan to 03 Jan
A. Middle Latitudes
Minor storm10%05%05%
Major-severe storm05%01%01%
B. High Latitudes
Minor storm15%10%05%
Major-severe storm10%05%01%

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