Joint USAF/NOAA Report of Solar and Geophysical Activity 09 Dec 2004

Space Environment Center and the U.S. Air Force.
Updated 2004 Dec 09 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 344 Issued at 2200Z on 09 Dec 2004

IA. Analysis of Solar Active Regions and Activity from 08/2100Z
to 09/2100Z: Solar activity was low. A single C1/Sf flare occurred
in Region 710 (S07E33) at 09/0012Z. Limited LASCO imagery revealed
what is likely a full halo CME associated with yesterday’s long
duration C2/Sf flare and filament eruption at 08/1959Z. No other
activity of note occurred.

IB. Solar Activity Forecast: Solar activity is expected to be very
low. There is a slight chance for a low C-class flare.

IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z:
The geomagnetic field was quiet to unsettled with an isolated active
period between 09/0900 – 1200Z. A sustained period of southward Bz
produced the active conditions. Solar wind speed declined to near
400 km/s. The greater than 2 MeV electron flux at geosynchronous
orbit was at high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to range from quiet to major storming. Quiet to unsettled
conditions are expected on 10 December. Transient flow associated
with the long duration C2 flare and CME on 09 December is expected
to arrive on 11 December. Expect active to minor storm levels with
isolated major storm periods on 11 and 12 December. A return to
quiet to occasional active levels are expected by the end of the
three-day period.

III. Event Probabilities 10 Dec-12 Dec

• Class M 05/05/05
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 09 Dec 087
• Predicted 10 Dec-12 Dec 085/085/090
• 90 Day Mean 09 Dec 106

V. Geomagnetic A Indices

• Observed Afr/Ap 08 Dec 009/010
• Estimated Afr/Ap 09 Dec 010/009
• Predicted Afr/Ap 10 Dec-12 Dec 008/008-020/020-030/030

VI. Geomagnetic Activity Probabilities 10 Dec-12 Dec

A. Middle Latitudes

• Active 25/35/40
• Minor storm 05/20/25
• Major-severe storm 01/10/10

B. High Latitudes

• Active 30/45/50
• Minor storm 10/25/30
• Major-severe storm 01/15/15