Joint USAF/NOAA Report of Solar and Geophysical Activity 12 Dec 2008

Product: Report of Solar-Geophysical Activity
Issued: 2008 Dec 12 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 347 Issued at 2200Z on 12 Dec 2008

IA. Analysis of Solar Active Regions and Activity from 11/2100Z to 12/2100Z: Solar activity was very low. Region 1009 (S25W90) produced a few A-class flares as it approached the west limb. A filament centered at about N50W15 erupted between 0600-0800Z which led to a slow CME off the northwest limb as observed by the SOHO C2 coronagraph beginning at 0930Z.

IB. Solar Activity Forecast: Solar activity is expected to be very low for the next three days (13-15 December).

IIA. Geophysical Activity Summary 11/2100Z to 12/2100Z: The geomagnetic field was quiet.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled with a chance for isolated active periods during the next 24 hours (13 December) as a high speed stream is expected to rotate into geoeffective position. Activity is expected to be generally quiet for the second and third days (14-15 December). The CME mentioned in Part IA is not expected to be geoeffective.

III. Event Probabilities 13 Dec-15 Dec

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

IV. Penticton 10.7 cm Flux

• Observed 12 Dec 071
• Predicted 13 Dec-15 Dec 070/070/068
• 90 Day Mean 12 Dec 068

V. Geomagnetic A Indices

• Observed Afr/Ap 11 Dec 004/003
• Estimated Afr/Ap 12 Dec 007/008
• Predicted Afr/Ap 13 Dec-15 Dec 010/010-005/005-005/005

VI. Geomagnetic Activity Probabilities 13 Dec-15 Dec

A. Middle Latitudes

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

B. High Latitudes

• Active 30/15/05
• Minor storm 10/01/01
• Major-severe storm 05/01/01