Joint USAF/NOAA Report of Solar and Geophysical Activity 23 Dec 2002
SDF Number 357 Issued at 2200Z on 23 Dec 2002
IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity was at low levels. The largest event
was a C3 flare from Region 226 (S28W78) at 23/0719 UTC. Region 226
continues its gradual decay and has simplified to a beta-gamma
magnetic configuration. Region 224 (S15W68) has shown rapid growth
in the last 24 hours with increasing penumbral coverage to 470
millionths. This region has also developed a beta-gamma magnetic
configuration. Region 229 (N22W51) has decreased in magnetic
complexity to a simple beta configuration. New Region 233 (N11E42)
was numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate. Regions 224, 226, and 230 have the potential for
M-class activity.
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was at unsettled to minor storm levels.
Sustained southward Bz and a six-hour period of elevated solar wind
velocity (peak velocity 600 km/s) resulted in active conditions at
mid-latitudes and minor storm conditions on the planetary index.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels with a chance of
isolated active conditions. A weak CME shock is possible on day one
of the period due to the M1 event that occurred on 21 December.
Days two and three of the forecast period are expected to be quiet
to unsettled.
III. Event Probabilities 24 Dec-26 Dec
- Class M 50/40/30
- Class X 10/05/05
- Proton 05/01/01
- PCAF yellow
IV. Penticton 10.7 cm Flux
- Observed 23 Dec 159
- Predicted 24 Dec-26 Dec 150/145/140
- 90 Day Mean 23 Dec 167
V. Geomagnetic A Indices
- Observed Afr/Ap 22 Dec 009/012
- Estimated Afr/Ap 23 Dec 018/020
- Predicted Afr/Ap 24 Dec-26 Dec 015/015-012/012-008/010
VI. Geomagnetic Activity Probabilities 24 Dec-26 Dec
A. Middle Latitudes
- Active 20/15/10
- Minor storm 10/05/01
- Major-severe storm 01/01/01
B. High Latitudes
- Active 25/10/10
- Minor storm 15/05/01
- Major-severe storm 01/01/01
