Joint USAF/NOAA Report of Solar and Geophysical Activity 19 Dec 2002
SDF Number 353 Issued at 2200Z on 19 Dec 2002
IA. Analysis of Solar Active Regions and Activity from 18/2100Z
to 19/2100Z: Solar activity was at low levels. Region 226 (S28W28)
produced multiple low level C-class flares. The largest optically
correlated event was a C2.7/Sf flare that occurred at 19/0035 UTC.
Magnetic analysis of this region depicts a complex delta structure
continuing in the intermediate cluster of penumbral spots. Region
229 (N19W03) was quiescent through the period. White-light analysis
shows decay in areal coverage as a weak gamma magnetic structure
remains evident in the central portion of this region’s spot complex.
Region 230 (S08E32) has continued to grow and now has a weak gamma
magnetic structure seen in the trailing portion of the region. This
region was also responsible for minor C-class flare activity early
in the period. New Region 231 (S25E13) was assigned today.
IB. Solar Activity Forecast: Solar activity is expected to be at
moderate levels. Regions 226, 229, and 230 all are capable of
producing M-class flares. There is a slight chance of a major flare
occurring in Region 226.
IIA. Geophysical Activity Summary 18/2100Z to 19/2100Z:
The geomagnetic field was at unsettled to minor storm levels. A
favorably positioned recurrent coronal hole and the resulting high
speed stream are responsible for the elevated conditions.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at unsettled to minor storm levels through day one of
the forecast period, becoming predominantly unsettled to active
levels on day two and returning to quiet to unsettled conditions by
day three.
III. Event Probabilities 20 Dec-22 Dec
- Class M 55/55/55
- Class X 10/10/10
- Proton 05/05/05
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 19 Dec 193
- Predicted 20 Dec-22 Dec 195/195/185
- 90 Day Mean 19 Dec 166
V. Geomagnetic A Indices
- Observed Afr/Ap 18 Dec 002/006
- Estimated Afr/Ap 19 Dec 020/025
- Predicted Afr/Ap 20 Dec-22 Dec 015/020-010/012-008/010
VI. Geomagnetic Activity Probabilities 20 Dec-22 Dec
A. Middle Latitudes
- Active 30/20/15
- Minor storm 15/05/01
- Major-severe storm 05/01/01
B. High Latitudes
- Active 35/25/20
- Minor storm 25/10/05
- Major-severe storm 10/05/01
