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

Product: Report of Solar-Geophysical Activity
Issued: 2007 Dec 31 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 365 Issued at 2200Z on 31 Dec 2007

IA. Analysis of Solar Active Regions and Activity from 30/2100Z to 31/2100Z: Solar activity was low. A C8.3 flare occurred at 31/0111Z accompanied by Type II and Type IV radio sweeps (estimated shock speed 682 km/s). An associated CME was observed on the east limb near S09. The bright region from which the event originated has been assigned Region 980 (S09E90).

IB. Solar Activity Forecast: Solar activity is expected to continue at low levels with a slight chance of an M-Class flare from Region 980.

IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z: The geomagnetic field was quiet. The greater than 2 MeV electrons at geosynchronous orbit remained at high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to remain quiet.

III. Event Probabilities 01 Jan-03 Jan

• Class M 15/15/15
• Class X 05/05/05
• Proton 01/01/01
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 31 Dec 077
• Predicted 01 Jan-03 Jan 078/080/085
• 90 Day Mean 31 Dec 072

V. Geomagnetic A Indices

• Observed Afr/Ap 30 Dec 003/002
• Estimated Afr/Ap 31 Dec 005/005
• Predicted Afr/Ap 01 Jan-03 Jan 005/005-005/005-005/005

VI. Geomagnetic Activity Probabilities 01 Jan-03 Jan

A. Middle Latitudes

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

B. High Latitudes

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