Joint USAF/NOAA Report of Solar and Geophysical Activity 23 Dec 2004

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Updated 2004 Dec 23 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 358 Issued at 2200Z on 23 Dec 2004

IA. Analysis of Solar Active Regions and Activity from 22/2100Z
to 23/2100Z: Solar activity was low. Region 713 (S08W06) produced
several C-class events. The largest was a C5 at 23/1008 UTC. This
flare was optically correlated with the GOES X-ray imager data.

IB. Solar Activity Forecast: Solar activity is expected to be very
low to low.

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was predominately quiet.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled. Isolated active conditions are
possible on 26 December with the affects from a recurrent coronal
hole.

III. Event Probabilities 24 Dec-26 Dec

• Class M 10/10/10
• Class X 01/01/01
• Proton 01/01/01
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 23 Dec 096
• Predicted 24 Dec-26 Dec 105/105/105
• 90 Day Mean 23 Dec 104

V. Geomagnetic A Indices

• Observed Afr/Ap 22 Dec 012/019
• Estimated Afr/Ap 23 Dec 005/005
• Predicted Afr/Ap 24 Dec-26 Dec 010/010-012/012-015/015

VI. Geomagnetic Activity Probabilities 24 Dec-26 Dec

A. Middle Latitudes

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

B. High Latitudes

• Active 25/25/30
• Minor storm 15/15/15
• Major-severe storm 01/01/05