Joint USAF/NOAA Report of Solar and Geophysical Activity 28 Aug 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Aug 28 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 240 Issued at 2200Z on 28 Aug 2007

IA. Analysis of Solar Active Regions and Activity from 27/2100Z to 28/2100Z: Solar activity has been very low. Region 969 (S05W19) is now a beta spot group.

IB. Solar Activity Forecast: Solar activity is expected to be very low.

IIA. Geophysical Activity Summary 27/2100Z to 28/2100Z: The geomagnetic field has been quiet to active. A transient disruption in the solar wind occurred at approximately 0930 UTC. This resulted in one period of minor storming at mid-latitudes and one period of major storming at high-latitudes. 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 quiet to unsettled for 29 August. There is a chance for isolated active periods due to the continued influence of a recurrent coronal hole high speed stream. The geomagnetic field is expected to abate to quiet for 30 – 31 August.

III. Event Probabilities 29 Aug-31 Aug

• Class M 01/01/01
• Class X 01/01/01
• Proton 01/01/01
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 28 Aug 070
• Predicted 29 Aug-31 Aug 070/070/070
• 90 Day Mean 28 Aug 072

V. Geomagnetic A Indices

• Observed Afr/Ap 27 Aug 010/012
• Estimated Afr/Ap 28 Aug 010/012
• Predicted Afr/Ap 29 Aug-31 Aug 006/008-004/005-002/005

VI. Geomagnetic Activity Probabilities 29 Aug-31 Aug

A. Middle Latitudes

• Active 30/20/20
• Minor storm 10/05/05
• Major-severe storm 01/01/01

B. High Latitudes

• Active 35/25/25
• Minor storm 15/10/10
• Major-severe storm 05/01/01