Report of Solar-Geophysical Activity
Issued: 2005 Sep 18 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA, # Space Environment Center and the U.S. Air Force.

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