Joint USAF/NOAA Report of Solar and Geophysical Activity 23 Dec 2006

Product: Report of Solar-Geophysical Activity
Issued: 2006 Dec 23 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 357 Issued at 2200Z on 23 Dec 2006

IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity was very low.

IB. Solar Activity Forecast: Solar activity is expected to continue at very low levels.

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field was quiet to active. Solar wind speed at ACE has decreased from approximately 670 km/s to 570 km/s. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled. Isolated active periods are possible on 24 December.

III. Event Probabilities 24 Dec-26 Dec

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

IV. Penticton 10.7 cm Flux

• Observed 23 Dec 073
• Predicted 24 Dec-26 Dec 075/075/075
• 90 Day Mean 23 Dec 082

V. Geomagnetic A Indices

• Observed Afr/Ap 22 Dec 010/014
• Estimated Afr/Ap 23 Dec 010/015
• Predicted Afr/Ap 24 Dec-26 Dec 008/008-005/005-005/005

VI. Geomagnetic Activity Probabilities 24 Dec-26 Dec

A. Middle Latitudes

• Active 20/15/15
• Minor storm 05/05/05
• Major-severe storm 01/01/01

B. High Latitudes

• Active 25/20/15
• Minor storm 15/05/05
• Major-severe storm 05/01/01