Joint USAF/NOAA Report of Solar and Geophysical Activity 31 Aug 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Aug 31 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 243 Issued at 2200Z on 31 Aug 2007

IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity was very low. Three B-class flares were observed during the past 24 hours.

IB. Solar Activity Forecast: Solar activity is expected to remain very low for the next three days (1 September – 3 September)

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field was mostly quiet. The greater than 2 MeV electron flux reached high levels again today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to become unsettled to active on day 1 (1 September) as a recurrent coronal hole becomes geoeffective. Mostly unsettled conditions are expected on days 2 through 3 (2 September – 3 September).

III. Event Probabilities 01 Sep-03 Sep

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

IV. Penticton 10.7 cm Flux

• Observed 31 Aug 071
• Predicted 01 Sep-03 Sep 071/071/070
• 90 Day Mean 31 Aug 071

V. Geomagnetic A Indices

• Observed Afr/Ap 30 Aug 004/006
• Estimated Afr/Ap 31 Aug 007/015
• Predicted Afr/Ap 01 Sep-03 Sep 015/025-010/012-010/012

VI. Geomagnetic Activity Probabilities 01 Sep-03 Sep

A. Middle Latitudes

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

B. High Latitudes

• Active 40/25/25
• Minor storm 20/15/10
• Major-severe storm 15/10/05