Joint USAF/NOAA Report of Solar and Geophysical Activity 21 May 2007
Product: Report of Solar-Geophysical Activity
Issued: 2007 May 21 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 141 Issued at 2200Z on 21 May 2007
IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was very low. Region 956 (N03W32) is decaying but continues to produce occasional B-class flares.
IB. Solar Activity Forecast: Solar activity is expected to continue at very low levels. There is slight chance for a C-class flare from Region 956.
IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was quiet with isolated unsettled periods. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.
IIB. Geophysical Activity Forecast: The geomagnetic field is expected to range from quiet to minor storm levels. A weak CME observed on 19 May may produce isolated unsettled to active periods on 22 May. A high speed coronal hole stream will rotate into a geoeffective position on 24 May and produce occasional active to minor storm periods.
III. Event Probabilities 22 May-24 May
- Class M 05/05/05
- Class X 01/01/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 21 May 073
- Predicted 22 May-24 May 075/075/075
- 90 Day Mean 21 May 074
V. Geomagnetic A Indices
- Observed Afr/Ap 20 May 006/006
- Estimated Afr/Ap 21 May 005/012
- Predicted Afr/Ap 22 May-24 May 005/008-005/005-010/015
VI. Geomagnetic Activity Probabilities 22 May-24 May
A. Middle Latitudes
- Active 15/15/30
- Minor storm 01/01/10
- Major-severe storm 01/01/05
B. High Latitudes
- Active 20/20/40
- Minor storm 05/05/20
- Major-severe storm 01/01/10
