Joint USAF/NOAA Report of Solar and Geophysical Activity 11 Sep 2004

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

Updated 2004 Sep 11 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 255 Issued at 2200Z on 11 Sep 2004

IA. Analysis of Solar Active Regions and Activity from 10/2100Z
to 11/2100Z: Solar activity remained at low levels today. Region
672 (N05E47) produced several B and C-class flares, the largest was
a C1.6 x-ray event that occurred at 11/0006Z. This region has
become slightly more magnetically complicated with gamma structures
now visible in the trailing portion of region. Regions 667 (S11W58)
and 669 (S06W51) were quiescent today and remain simply structured
magnetic beta groups. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at
predominantly low levels throughout the period. There is a slight
chance for an isolated M-class event from Region 672.

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z:
The geomagnetic field was at quiet to unsettled levels today.

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

III. Event Probabilities 12 Sep-14 Sep

• Class M 30/30/30
• Class X 01/01/01
• Proton 01/01/01
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 11 Sep 116
• Predicted 12 Sep-14 Sep 115/110/100
• 90 Day Mean 11 Sep 112

V. Geomagnetic A Indices

• Observed Afr/Ap 10 Sep 001/005
• Estimated Afr/Ap 11 Sep 001/006
• Predicted Afr/Ap 12 Sep-14 Sep 003/008-008/010-008/010

VI. Geomagnetic Activity Probabilities 12 Sep-14 Sep

A. Middle Latitudes

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

• B. High Latitudes
• Active 15/20/20
• Minor storm 05/05/05
• Major-severe storm 01/01/01