Joint USAF/NOAA Report of Solar and Geophysical Activity 24 Sep 2004

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

Updated 2004 Sep 24 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 268 Issued at 2200Z on 24 Sep 2004

IA. Analysis of Solar Active Regions and Activity from 23/2100Z
to 24/2100Z: Solar activity decreased to very low levels. Region
673 (S13W44) produced several minor B-class flares. The largest was
a B5 x-ray flare that occurred at 24/0245Z. This region exhibits a
simple beta class magnetic structure and is the only spotted active
region reported today. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at
very low levels. Region 673 has a slight chance of producing an
isolated C-class flare.

IIA. Geophysical Activity Summary 23/2100Z to 24/2100Z:
The geomagnetic field was at quiet to unsettled levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at quiet to unsettled levels throughout the period.

III. Event Probabilities 25 Sep-27 Sep

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

IV. Penticton 10.7 cm Flux

• Observed 24 Sep 089
• Predicted 25 Sep-27 Sep 090/090/095
• 90 Day Mean 24 Sep 111

V. Geomagnetic A Indices

• Observed Afr/Ap 23 Sep 010/012
• Estimated Afr/Ap 24 Sep 004/008
• Predicted Afr/Ap 25 Sep-27 Sep 004/008-005/008-005/008

VI. Geomagnetic Activity Probabilities 25 Sep-27 Sep

A. Middle Latitudes

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

B. High Latitudes

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