Joint USAF/NOAA Report of Solar and Geophysical Activity 15 Sep 2004

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

Updated 2004 Sep 15 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 259 Issued at 2200Z on 15 Sep 2004

IA. Analysis of Solar Active Regions and Activity from 14/2100Z
to 15/2100Z: Solar activity has been low. Region 672 (N05W03) is a
magnetic complex beta-delta region but has neither shown any real
growth nor decay since 14 Sep. Region 673 (S13E72) was newly
numbered today.

IB. Solar Activity Forecast: Solar activity is expected to remain
low. There is a chance for isolated M-level flare activity from
Region 672 (N05W03).

IIA. Geophysical Activity Summary 14/2100Z to 15/2100Z:
The geomagnetic field has been at quiet to active levels. A greater
than 10 MeV proton flux event which began on 13 Sep at 2205Z fell
below threshold on 15 Sep at 1015Z. The event reached a maximum of
237 PFU on 14 Sep at 0005Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to remain at unsettled to active levels from 16 Sep through
18 Sep due to the arrival of a weak coronal mass ejection that
occurred on 14 Sep at 0930Z. During the arrival of a shock driven
by this event, there is a small chance that the greater than 10 MeV
proton levels will be enhanced.

III. Event Probabilities 16 Sep-18 Sep

• Class M 25/25/25
• Class X 05/05/05
• Proton 05/05/05
• PCAF Green

IV. Penticton 10.7 cm Flux

• Observed 15 Sep 110
• Predicted 16 Sep-18 Sep 115/115/115
• 90 Day Mean 15 Sep 112

V. Geomagnetic A Indices

• Observed Afr/Ap 14 Sep 017/028
• Estimated Afr/Ap 15 Sep 010/015
• Predicted Afr/Ap 16 Sep-18 Sep 015/025-015/025-010/015

VI. Geomagnetic Activity Probabilities 16 Sep-18 Sep

A. Middle Latitudes

• Active 40/40/35
• Minor storm 15/15/10
• Major-severe storm 05/05/01

B. High Latitudes

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