Joint USAF/NOAA Report of Solar and Geophysical Activity 22 Apr 2008
Product: Report of Solar-Geophysical Activity
Issued: 2008 Apr 22 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Weather Prediction Center and the U.S. Air Force.
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 113 Issued at 2200Z on 22 Apr 2008
IA. Analysis of Solar Active Regions and Activity from 21/2100Z to 22/2100Z: Solar activity was very low. No flares occurred during the past 24 hours. New Region 992 (N13W01) emerged today as a small, C-type sunspot group.
IB. Solar Activity Forecast: Solar activity is expected to be very low for the next three days (23-25 April).
IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field was quiet from the beginning of the period through about 1500Z. Since then activity has been unsettled. Real-time solar wind data from ACE indicate a possible solar sector boundary from ‘away’ orientation (positive) to ‘towards’ orientation (negative) at about 1410Z.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be mostly unsettled with a chance for isolated active periods for the first and second days (23-24 April). The elevated activity is expected in response to a coronal hole which should be in a favorable position on those days. Activity is expected to decline to quiet to unsettled for the third day (25 April).
III. Event Probabilities 23 Apr-25 Apr
- Class M 01/01/01
- Class X 01/01/01
- Proton 01/01/01
- PCAF Green
IV. Penticton 10.7 cm Flux
- Observed 22 Apr 071
- Predicted 23 Apr-25 Apr 075/075/075
- 90 Day Mean 22 Apr 072
V. Geomagnetic A Indices
- Observed Afr/Ap 21 Apr 003/004
- Estimated Afr/Ap 22 Apr 007/008
- Predicted Afr/Ap 23 Apr-25 Apr 012/015-012/012-007/008
VI. Geomagnetic Activity Probabilities 23 Apr-25 Apr
A. Middle Latitudes
- Active 40/40/15
- Minor storm 10/10/05
- Major-severe storm 05/05/01
B. High Latitudes
- Active 40/40/15
- Minor storm 15/15/05
- Major-severe storm 05/05/01