Joint USAF/NOAA Report of Solar and Geophysical Activity 17 Oct 2004
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 Oct 17 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 291 Issued at 2200Z on 17 Oct 2004
IA. Analysis of Solar Active Regions and Activity from 16/2100Z
to 17/2100Z: Solar activity continued at very low levels with
occasional B-class flares. Region 682 (S14E10) has shown some decay
in white light area coverage, but still maintains minor magnetic
complexity. New Region 683 (S09E22) emerged as a C type group early
in the period. New Region 684 (S04E65) was also numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low. Isolated minor C-class flares are possible.
IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was quiet. Very stable solar wind conditions
persisted through the period. Solar wind speed declined to near 300
km/s and IMF Bz remains near zero. The greater than 2 MeV electron
flux at geosynchronous orbit was high, and has been at high levels
since 14 October.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled. Isolated active periods are
possible on 19 October due to a weak high speed solar wind stream.
III. Event Probabilities 18 Oct-20 Oct
- Class M 10/10/10
- Class X 01/01/01
- Proton 01/01/01
- PCAF Green
IV. Penticton 10.7 cm Flux
- Observed 17 Oct 092
- Predicted 18 Oct-20 Oct 095/090/090
- 90 Day Mean 17 Oct 106
V. Geomagnetic A Indices
- Observed Afr/Ap 16 Oct 003/005
- Estimated Afr/Ap 17 Oct 003/004
- Predicted Afr/Ap 18 Oct-20 Oct 008/010-010/015-010/012
VI. Geomagnetic Activity Probabilities 18 Oct-20 Oct
A. Middle Latitudes
- Active 15/20/20
- Minor storm 05/05/05
- Major-severe storm 01/01/01
B. High Latitudes
- Active 25/30/25
- Minor storm 10/15/10
- Major-severe storm 05/05/05
