Joint USAF/NOAA Report of Solar and Geophysical Activity 08 Sep 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Sep 08 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 252 Issued at 2200Z on 08 Sep 2008

IA. Analysis of Solar Active Regions and Activity from 07/2100Z to 08/2100Z: Solar activity was very low. No flares were observed. The visible disk remained spotless.

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

IIA. Geophysical Activity Summary 07/2100Z to 08/2100Z: Geomagnetic field activity was at quiet to unsettled levels. ACE solar wind data indicated Earth remained within a recurrent coronal hole high-speed stream. However, solar wind velocities gradually decreased from a high of 624 km/sec at 07/2131Z to a low of 534 km/sec at 08/2043Z. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to be at predominantly quiet levels through the forecast period (09 – 11 September).

III. Event Probabilities 09 Sep-11 Sep

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

IV. Penticton 10.7 cm Flux

• Observed 08 Sep 067
• Predicted 09 Sep-11 Sep 066/066/066
• 90 Day Mean 08 Sep 066

V. Geomagnetic A Indices

• Observed Afr/Ap 07 Sep 007/008
• Estimated Afr/Ap 08 Sep 007/005
• Predicted Afr/Ap 09 Sep-11 Sep 005/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 09 Sep-11 Sep

A. Middle Latitudes

• Active 10/10/10
• Minor storm 01/01/01
• Major-severe storm 01/01/01

B. High Latitudes

• Active 15/15/15
• Minor storm 01/01/01
• Major-severe storm 01/01/01