Joint USAF/NOAA Report of Solar and Geophysical Activity 24 Dec 2002
SDF Number 358 Issued at 2200Z on 24 Dec 2002
IA. Analysis of Solar Active Regions and Activity from 23/2100Z
to 24/2100Z: Solar activity was at low levels. Region 224 (S14W81)
produced two C5 flares. The first one at 24/0527 UTC and the second
one at 24/1451 UTC. Region 224 has stopped its growth phase of the
last few days. Region 226 (S28W89) continues to gradually decay and
has simplied to a beta magnetic configuration. New Region 234
(N18E73) was numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be low
to moderate. Region 230 has the potential for M-class activity.
Regions 224 and 226 also have M-class potential as they rotate
beyond the west limb.
IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z:
The geomagnetic field was at quiet to active levels. A weak
transient was observed by the NASA/ACE spacecraft at approximately
24/1300 UTC. Solar wind speed increased to near 575 km/s and Bz was
slightly negative. The greater than 2 MeV electron flux at
geo-synchronous orbit reached high levels today.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled with a chance of isolated active
conditions. Isolated active conditions may continue into day one of
the forecast period. By late on day one and through day two
activity is expected to be quiet to unsettled. Coronal hole effects
are expected to commence on day three of the period with isolated
active conditions possible.
III. Event Probabilities 25 Dec-27 Dec
- Class M 40/30/25
- Class X 05/05/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 24 Dec 147
- Predicted 25 Dec-27 Dec 145/140/140
- 90 Day Mean 24 Dec 167
V. Geomagnetic A Indices
- Observed Afr/Ap 23 Dec 012/026
- Estimated Afr/Ap 24 Dec 015/015
- Predicted Afr/Ap 25 Dec-27 Dec 012/010-008/012-012/015
VI. Geomagnetic Activity Probabilities 25 Dec-27 Dec
A. Middle Latitudes
- Active 15/10/20
- Minor storm 05/01/10
- Major-severe storm 01/01/01
B. High Latitudes
- Active 15/15/25
- Minor storm 05/05/15
- Major-severe storm 01/01/01
