Joint USAF/NOAA Report of Solar and Geophysical Activity 16 Aug 2004
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 Aug 16 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 229 Issued at 2200Z on 16 Aug 2004
IA. Analysis of Solar Active Regions and Activity from 15/2100Z
to 16/2100Z: Solar activity decreased to moderate levels today.
Region 656 (S13W61) was limited to a single M-class flare during the
period, an M1/Sf that occurred at 16/0347Z. A long duration C9/Sf
event occurred at 16/1338Z which produced a very faint CME that does
not appear to be Earth-directed. Region 656 underwent little change
in spot area. The region remains a beta-gamma-delta magnetic
complex although the delta structure in the intermediate spot
cluster has weakened over the period. Region 661 (N07E34) was
quiescent throughout the period but is worthy of note due to the
small delta magnetic structure that has developed in the southern
most part of the dominant trailing spot. A partial halo CME was
observed mostly on the northwest solar limb which appears to be a
backsided event. No new regions were numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be at
moderate to high levels through 17 and 18 August. Activity should
begin to diminish on 19 August as Region 656 transits the western
solar limb.
IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z:
The geomagnetic field was at quiet to unsettled 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 quiet to unsettled levels. A slight chance for
isolated active conditions throughout the period exists due to the
weak CME activity seen during the past several days.
III. Event Probabilities 17 Aug-19 Aug
- Class M 75/75/50
- Class X 20/20/05
- Proton 10/10/05
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 16 Aug 134
- Predicted 17 Aug-19 Aug 130/125/115
- 90 Day Mean 16 Aug 108
V. Geomagnetic A Indices
- Observed Afr/Ap 15 Aug 003/007
- Estimated Afr/Ap 16 Aug 003/008
- Predicted Afr/Ap 17 Aug-19 Aug 008/008-008/008-005/008
VI. Geomagnetic Activity Probabilities 17 Aug-19 Aug
A. Middle Latitudes
- Active 15/15/10
- Minor storm 05/05/01
- Major-severe storm 01/01/01
B. High Latitudes
- Active 20/20/20
- Minor storm 05/05/05
- Major-severe storm 01/01/01
