Joint USAF/NOAA Report of Solar and Geophysical Activity 10 Dec 2007

Product: Report of Solar-Geophysical Activity
Issued: 2007 Dec 10 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 344 Issued at 2200Z on 10 Dec 2007

IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity was very low. Region 978 (S08E14) grew in complexity over the past day and is currently a beta-gamma magnetic type.

IB. Solar Activity Forecast: Solar activity is expected to range from very low to low. The trend in Region 978 suggest a good chance for C-class activity..

IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field was quiet to unsettled. Solar wind speeds at ACE began to increase, approaching 440 km/s by 1800Z. Temperature and density trends also signal the approach of a coronal hole high speed stream.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to become unsettled early in the period as the recurrent coronal hole high speed stream becomes geoeffective. Occasional active periods may occur, particularly at high latitudes. Extrapolation from STEREO Behind suggests a peak speed near 600 km/s by 11 November at 1000Z. The disturbed conditions are exptected to diminish by 13 December.

III. Event Probabilities 11 Dec-13 Dec

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

IV. Penticton 10.7 cm Flux

• Observed 10 Dec 087
• Predicted 11 Dec-13 Dec 085/085/080
• 90 Day Mean 10 Dec 068

V. Geomagnetic A Indices

• Observed Afr/Ap 09 Dec 001/002
• Estimated Afr/Ap 10 Dec 005/008
• Predicted Afr/Ap 11 Dec-13 Dec 008/012-008/010-007/005

VI. Geomagnetic Activity Probabilities 11 Dec-13 Dec

A. Middle Latitudes

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

B. High Latitudes

• Active 25/25/15
• Minor storm 15/15/10
• Major-severe storm 06/06/06