Joint USAF/NOAA Report of Solar and Geophysical Activity 28 Aug 2005
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Aug 28 2203 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 240 Issued at 2200Z on 28 Aug 2005
IA. Analysis of Solar Active Regions and Activity from 27/2100Z
to 28/2100Z: Solar activity increased to moderate levels today.
Region 803 (N11E27) produced the largest flare of the period, an
impulsive M1/Sf event that occurred at 28/1028Z. This region
underwent some decay of penumbral coverage during the period with a
delta structure materializing in the leading portion of this
reversed polarity spot group. A disappearing solar filament was
reported in the southwest solar quadrant, occurring between 28/0755
and 0946Z. The remaining spotted groups were quiescent over the
past 24 hours. No new regions were numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be at
low levels. Region 803 is capable of producing further isolated
M-class flare activity.
IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z:
The geomagnetic field was at predominantly quiet levels. The greater
than 2 MeV electron flux at geosynchronous orbit reached high levels
today.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at predominantly quiet to unsettled levels for 29-31
August.
III. Event Probabilities 29 Aug-31 Aug
- Class M 30/30/30
- Class X 01/01/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 28 Aug 090
- Predicted 29 Aug-31 Aug 090/085/085
- 90 Day Mean 28 Aug 093
V. Geomagnetic A Indices
- Observed Afr/Ap 27 Aug 004/007
- Estimated Afr/Ap 28 Aug 004/006
- Predicted Afr/Ap 29 Aug-31 Aug 005/008-005/008-005/012
VI. Geomagnetic Activity Probabilities 29 Aug-31 Aug
A. Middle Latitudes
- Active 15/15/15
- Minor storm 01/01/01
- Major-severe storm 01/01/01
B. High Latitudes
- Active 15/15/20
- Minor storm 05/05/10
- Major-severe storm 01/01/05
