Joint USAF/NOAA Report of Solar and Geophysical Activity 13 Apr 2004
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 Apr 13 2200 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 104 Issued at 2200Z on 13 Apr 2004
IA. Analysis of Solar Active Regions and Activity from 12/2100Z
to 13/2100Z: Solar activity was at very low levels. A single
B-class flare occurred at 13/0532Z on the northeast limb. There was
no other significant activity observed today. Region 588 (S13W80)
has shown decreasing area coverage and has simplified in magnetic
complexity to an alpha configuration. New Region 592 (S12E59) was
numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be at
very low levels with a chance of low level activity. Increased
emissions on the east limb were observed in NOAA SXI imagery and
suggests returning regions over the next three days.
IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z:
The geomagnetic field was at quiet to unsettled levels. The greater
than 2 MeV electron flux reached high levels today.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels.
III. Event Probabilities 14 Apr-16 Apr
- Class M 05/01/01
- Class X 01/01/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 13 Apr 093
- Predicted 14 Apr-16 Apr 095/100/100
- 90 Day Mean 13 Apr 108
V. Geomagnetic A Indices
- Observed Afr/Ap 12 Apr 007/011
- Estimated Afr/Ap 13 Apr 008/008
- Predicted Afr/Ap 14 Apr-16 Apr 008/010-008/010-008/010
VI. Geomagnetic Activity Probabilities 14 Apr-16 Apr
A. Middle Latitudes
- Active 10/10/10
- Minor storm 05/05/05
- Major-severe storm 01/01/01
B. High Latitudes
- Active 20/20/20
- Minor storm 10/10/10
- Major-severe storm 01/01/01
