Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Sep 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Sep 20 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 264 Issued at 2200Z on 20 Sep 2008

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was very low. No flares were observed during the past 24 hours. The visible solar disk remains spotless.

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

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was quiet.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to remain at quiet levels for the forecast period (21-23 September).

III. Event Probabilities 21 Sep-23 Sep

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

IV. Penticton 10.7 cm Flux

• Observed 20 Sep 068
• Predicted 21 Sep-23 Sep 067/067/067
• 90 Day Mean 20 Sep 066

V. Geomagnetic A Indices

• Observed Afr/Ap 19 Sep 003/005
• Estimated Afr/Ap 20 Sep 003/005
• Predicted Afr/Ap 21 Sep-23 Sep 005/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 21 Sep-23 Sep

A. Middle Latitudes

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

B. High Latitudes

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