Joint USAF/NOAA Report of Solar and Geophysical Activity 23 Dec 2003
Prepared jointly by the U.S. Dept. of Commerce, NOAA, Space Environment Center and the U.S. Air Force.
Updated 2003 Dec 23 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 357 Issued at 2200Z on 23 Dec 2003
IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity was low. Occasional C-class flares were
observed from Regions 525 (N08W22) and 528 (N09E09). The largest
flare of the period was a C6 flare from Region 525 at 23/1024Z. This
region showed little change over the past 24 hours and continues to
exhibit some minor mixing of polarity. Region 528 is maintaining its
steady growth phase and now exceeds 500 millionths of white light
areal coverage in a beta-gamma magnetic configuration. No
significant changes were observed in the remaining active regions.
IB. Solar Activity Forecast: Solar activity is expected to be low.
There is a chance for an M-class flare from Regions 525 and 528.
IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was quiet to unsettled. The coronal hole high
speed stream that began on 21 December, has now rotated out of a
geoeffective position. Solar wind speed declined from a maximum of
near 650 km/s on 22 December, to approximately 500 km/s at the end
of this period.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled for the next three days.
III. Event Probabilities 24 Dec-26 Dec
- Class M 20/25/25
- Class X 05/05/05
- Proton 01/01/01
- PCAF Green
IV. Penticton 10.7 cm Flux
- Observed 23 Dec 142
- Predicted 24 Dec-26 Dec 145/150/150
- 90 Day Mean 23 Dec 137
V. Geomagnetic A Indices
- Observed Afr/Ap 22 Dec 018/015
- Estimated Afr/Ap 23 Dec 008/010
- Predicted Afr/Ap 24 Dec-26 Dec 005/010-005/010-005/010
VI. Geomagnetic Activity Probabilities 24 Dec-26 Dec
A. Middle Latitudes
- Active 15/10/10
- Minor storm 01/01/01
- Major-severe storm 01/01/01
B. High Latitudes
- Active 20/15/15
- Minor storm 05/01/01
- Major-severe storm 01/01/01