Joint USAF/NOAA Report of Solar and Geophysical Activity 16 Apr 2004
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 Apr 16 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 107 Issued at 2200Z on 16 Apr 2004
IA. Analysis of Solar Active Regions and Activity from 15/2100Z
to 16/2100Z: Solar activity was at very low levels. The largest
flare of the period was a B8 from newly numbered Region 595(S09E68).
Region 591(S16W52) continues to show signs of decay but still has
some weak polarity mixing.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low. Region 591 and 595 have the potential for C-class
activity.
IIA. Geophysical Activity Summary 15/2100Z to 16/2100Z:
The geomagnetic field was at quiet to active levels. Two periods of
active conditions were observed due to elevated wind speed and a
weak coronal hole influence.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels with a chance of
isolated active conditions due to elevated solar wind speeds.
III. Event Probabilities 17 Apr-19 Apr
- Class M 05/05/05
- Class X 01/01/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 16 Apr 097
- Predicted 17 Apr-19 Apr 100/100/100
- 90 Day Mean 16 Apr 108
V. Geomagnetic A Indices
- Observed Afr/Ap 15 Apr 003/006
- Estimated Afr/Ap 16 Apr 010/012
- Predicted Afr/Ap 17 Apr-19 Apr 008/012-006/010-003/008
VI. Geomagnetic Activity Probabilities 17 Apr-19 Apr
A. Middle Latitudes
- Active 25/20/10
- Minor storm 05/05/05
- Major-severe storm 01/01/01
B. High Latitudes
- Active 35/25/15
- Minor storm 10/10/05
- Major-severe storm 01/01/01
