Viewing archive of Friday, 21 December 2001
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 2001 Dec 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 355 Issued at 2200Z on 21 Dec 2001IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z Solar activity was low. Region 9742 (N10W03) is the
largest and most active group on the visible disk and produced
several minor C-class flares. This beta-gamma region continues to
grow in spot count, area, and magnetic complexity, and now exceeds
700 millionths of white light area. No remarkable activity or
developments were observed in the remaining active regions. New
Regions 9750 (S16W64) and 9751 (N04E68) were numbered today.
IB. Solar Activity Forecast
Solar activity is expected to be
moderate. Region 9742 has good potential for M-class flares and an
isolated chance for a major flare.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
The geomagnetic field was quiet to active. An increase in the solar
wind speed began at around 21/1100Z. This increase was accompanied
by sustained periods of southward Bz resulting in unsettled to
active periods at all latitudes.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to continue at quiet to active levels.
III. Event Probabilities 22 Dec to 24 Dec
| Class M | 60% | 60% | 60% |
| Class X | 10% | 10% | 10% |
| Proton | 05% | 05% | 05% |
| PCAF | green | ||
IV. Penticton 10.7 cm Flux
Observed 21 Dec 234 Predicted 22 Dec-24 Dec 240/240/240 90 Day Mean 21 Dec 218
V. Geomagnetic A Indices
Observed Afr/Ap 20 Dec 002/005 Estimated Afr/Ap 21 Dec 010/010 Predicted Afr/Ap 22 Dec-24 Dec 012/010-010/010-008/012
VI. Geomagnetic Activity Probabilities 22 Dec to 24 Dec
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 40% | 35% | 20% |
| Minor storm | 10% | 10% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 50% | 40% | 40% |
| Minor storm | 15% | 15% | 15% |
| Major-severe storm | 05% | 05% | 05% |
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