Joint USAF/NOAA Report of Solar and Geophysical Activity 18 Sep 2005
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force. Updated 2005 Sep 18 2204 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 261 Issued at 2200Z on 18 Sep 2005
IA. Analysis of Solar Active Regions and Activity from 17/2100Z to 18/2100Z: Solar activity was low. Region 808 (S11W63) continued to decay and simplify. Clouds and sensor outages made optical verification difficult, but it is likely that Region 808 produced the day’s largest event, a C3 at 0433 UTC. Little else of significance occurred.
IB. Solar Activity Forecast: Solar activity is expected to be low to moderate. Region 808 may still yield an energetic event before it reaches west limb.
IIA. Geophysical Activity Summary 17/2100Z to 18/2100Z: The geomagnetic field was quiet to mildly active. The greater than 2 MeV electron flux at geosynchronous orbit was high.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active for the next three days.
III. Event Probabilities 19 Sep-21 Sep
- Class M 50/50/50
- Class X 20/20/20
- Proton 20/20/20
- PCAF yellow
IV. Penticton 10.7 cm Flux
- Observed 18 Sep 102
- Predicted 19 Sep-21 Sep 100/095/095
- 90 Day Mean 18 Sep 093
V. Geomagnetic A Indices
- Observed Afr/Ap 17 Sep 010/012
- Estimated Afr/Ap 18 Sep 013/010
- Predicted Afr/Ap 19 Sep-21 Sep 010/010-010/020-010/015
VI. Geomagnetic Activity Probabilities 19 Sep-21 Sep
A. Middle Latitudes
- Active 30/30/30
- Minor storm 15/15/15
- Major-severe storm 05/05/05
B. High Latitudes
- Active 40/40/40
- Minor storm 15/15/15
- Major-severe storm 05/05/05
