Joint USAF/NOAA Report of Solar and Geophysical Activity 13 Sep 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Sep 13 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 257 Issued at 2200Z on 13 Sep 2008

IA. Analysis of Solar Active Regions and Activity from 12/2100Z to 13/2100Z: Solar activity was very low. No flares were observed during the past 24 hours and the visible solar disk remains spotless.

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

IIA. Geophysical Activity Summary 12/2100Z to 13/2100Z: The geomagnetic field was quiet. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled with isolated active levels for 14 September due to the approach of a recurrent coronal hole high speed stream. Predominately unsettled to active conditions, with isolated major storming at high latitudes, are expected for 15 September, Quiet to unsettled conditions are forecast for 16 September.

III. Event Probabilities 14 Sep-16 Sep

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

IV. Penticton 10.7 cm Flux

• Observed 13 Sep 066
• Predicted 14 Sep-16 Sep 066/066/066
• 90 Day Mean 13 Sep 066

V. Geomagnetic A Indices

• Observed Afr/Ap 12 Sep 000/002
• Estimated Afr/Ap 13 Sep 002/004
• Predicted Afr/Ap 14 Sep-16 Sep 010/015-015/020-007/008

VI. Geomagnetic Activity Probabilities 14 Sep-16 Sep

A. Middle Latitudes

• Active 25/30/20
• Minor storm 05/05/01
• Major-severe storm 01/01/01

B. High Latitudes

• Active 35/40/25
• Minor storm 10/15/05
• Major-severe storm 01/05/01