Joint USAF/NOAA Report of Solar and Geophysical Activity 17 Sep 2008
Product: Report of Solar-Geophysical Activity
Issued: 2008 Sep 17 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 261 Issued at 2200Z on 17 Sep 2008
IA. Analysis of Solar Active Regions and Activity from 16/2100Z to 17/2100Z: Solar activity was very low. No flares were observed during the past 24 hours. The visible disk remained spotless.
IB. Solar Activity Forecast: Solar activity is expected to be very low.
IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z: The geomagnetic field was predominately quiet. An isolated unsettled period was observed between 17/0300-0600Z. Solar wind speed measured at the ACE spacecraft showed a gradual decrease from approximately 530 km/s to 410 km/s during the forecast period. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels again today.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be predominately quiet with isolated unsettled conditions for the next three days (18-20 September).
III. Event Probabilities 18 Sep-20 Sep
- Class M 01/01/01
- Class X 01/01/01
- Proton 01/01/01
- PCAF Green
IV. Penticton 10.7 cm Flux
- Observed 17 Sep 067
- Predicted 18 Sep-20 Sep 066/066/066
- 90 Day Mean 17 Sep 066
V. Geomagnetic A Indices
- Observed Afr/Ap 16 Sep 007/009
- Estimated Afr/Ap 17 Sep 005/005
- Predicted Afr/Ap 18 Sep-20 Sep 005/005-005/005-005/005
VI. Geomagnetic Activity Probabilities 18 Sep-20 Sep
A. Middle Latitudes
- Active 10/10/10
- Minor storm 01/01/01
- Major-severe storm 01/01/01
B. High Latitudes
- Active 10/10/10
- Minor storm 01/01/01
- Major-severe storm 01/01/01