Joint USAF/NOAA Report of Solar and Geophysical Activity 17 Sep 2003
SDF Number 260 Issued at 2200Z on 17 Sep 2003
IA. Analysis of Solar Active Regions and Activity from 16/2100Z
to 17/2100Z: Solar activity was moderate. Region 456, just beyond
west limb near S08, produced an M1 flare at 16/2224 UTC. Coronal
loops were seen in association with the x-ray event. Few flares have
occurred since then, as the disk has been quiet and stable. One new
region was assigned, Region 463 (N09E74).
IB. Solar Activity Forecast: Solar activity is expected to be low.
IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was at quiet to severe storm levels. A brief
quiet period began the interval prior to the onset of the high speed
solar wind stream. The solar wind radial speed reached approximately
800 km/s at 1500 UTC. Its source is a large coronal hole located in
the western solar hemisphere. The greater than 2 MeV electron flux
at geosynchronous orbit reached high levels.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at active to minor storm levels for the next two
days, then calming to be unsettled to active by day three. The high
speed stream should buffet the magnetosphere for the majority of the
period.
III. Event Probabilities 18 Sep-20 Sep
- Class M 05/05/05
- Class X 01/01/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 17 Sep 106
- Predicted 18 Sep-20 Sep 110/110/105
- 90 Day Mean 17 Sep 120
V. Geomagnetic A Indices
- Observed Afr/Ap 16 Sep 015/037
- Estimated Afr/Ap 17 Sep 025/060
- Predicted Afr/Ap 18 Sep-20 Sep 025/040-020/025-015/025
VI. Geomagnetic Activity Probabilities 18 Sep-20 Sep
A. Middle Latitudes
- Active 55/50/40
- Minor storm 30/20/15
- Major-severe storm 05/05/05
B. High Latitudes
- Active 55/50/50
- Minor storm 35/25/20
- Major-severe storm 10/05/05
