Joint USAF/NOAA Report of Solar and Geophysical Activity 16 Dec 2004
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 Dec 16 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 351 Issued at 2200Z on 16 Dec 2004
IA. Analysis of Solar Active Regions and Activity from 15/2100Z
to 16/2100Z: Solar activity was very low. Region 710 (S06W61) was
responsible for a few B-class flares. A full halo CME observed on
LASCO imagery late on 15 December was determined to be a farside
event.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low. A new region rotating on the southeast limb may
slightly increase activity levels.
IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z:
The geomagnetic field was quiet to unsettled with isolated active
levels late in the period. A gradual increase in solar wind speed
began about 16/0500Z. Speed increased from near 350 km/s to 600
km/s by the end of the day. This is likely the onset of a recurrent
high speed stream.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to active with minor storm periods at high
latitudes on 17 and 18 December. Expect quiet to unsettled levels
with isolated active conditions on 19 December as the high speed
coronal hole stream subsides.
III. Event Probabilities 17 Dec-19 Dec
- Class M 05/05/05
- Class X 01/01/01
- Proton 01/01/01
- PCAF Green
IV. Penticton 10.7 cm Flux
- Observed 16 Dec 090
- Predicted 17 Dec-19 Dec 090/090/090
- 90 Day Mean 16 Dec 104
V. Geomagnetic A Indices
- Observed Afr/Ap 15 Dec 003/006
- Estimated Afr/Ap 16 Dec 008/010
- Predicted Afr/Ap 17 Dec-19 Dec 012/020-008/015-006/008
VI. Geomagnetic Activity Probabilities 17 Dec-19 Dec
A. Middle Latitudes
- Active 30/20/15
- Minor storm 15/10/10
- Major-severe storm 05/01/01
B. High Latitudes
- Active 35/25/25
- Minor storm 20/15/10
- Major-severe storm 10/05/05
