Joint USAF/NOAA Report of Solar and Geophysical Activity 26 Sep 2004

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

Updated 2004 Sep 26 2210 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 270 Issued at 2200Z on 26 Sep 2004

IA. Analysis of Solar Active Regions and Activity from 25/2100Z
to 26/2100Z: Solar activity was very low. Today’s activity consisted
of a few, low-level B-class flares. There are only two spotted
regions on the disk and both are small, stable, and magnetically
simple.

IB. Solar Activity Forecast: Solar activity is expected to be very
low for the next three days.

IIA. Geophysical Activity Summary 25/2100Z to 26/2100Z:
The geomagnetic field was quiet during the past 24 hours. The greater
than 2 MeV electrons reached high levels during the past 24 hours.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be quiet to unsettled for the next three days.

III. Event Probabilities 27 Sep-29 Sep
Class M 01/01/01
Class X 01/01/01
Proton 01/01/01
PCAF green

IV. Penticton 10.7 cm Flux
Observed 26 Sep 090
Predicted 27 Sep-29 Sep 090/090/095
90 Day Mean 26 Sep 111

V. Geomagnetic A Indices
Observed Afr/Ap 25 Sep 002/005
Estimated Afr/Ap 26 Sep 005/005
Predicted Afr/Ap 27 Sep-29 Sep 005/005-005/008-005/008

VI. Geomagnetic Activity Probabilities 27 Sep-29 Sep
A. Middle Latitudes
Active 20/20/20
Minor storm 15/15/15
Major-severe storm 05/05/05
B. High Latitudes
Active 20/20/20
Minor storm 15/15/15
Major-severe storm 05/05/05