Joint USAF/NOAA Report of Solar and Geophysical Activity 25 Sep 2005

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Sep 25 2204 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 268 Issued at 2200Z on 25 Sep 2005

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity has been very low. Regions 810 (N08W35) and 812 (S02E45) produced no flares, and exhibited no significant development. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be very low. Slight chance of C-class flares possible from Region 810.

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field was quiet. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet all three days, with a moderate chance of unsettled to active conditions on 27-28 September.

III. Event Probabilities 26 Sep-28 Sep

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

IV. Penticton 10.7 cm Flux

• Observed 25 Sep 081
• Predicted 26 Sep-28 Sep 080/080/080
• 90 Day Mean 25 Sep 094

V. Geomagnetic A Indices

• Observed Afr/Ap 24 Sep 002/004
• Estimated Afr/Ap 25 Sep 003/005
• Predicted Afr/Ap 26 Sep-28 Sep 005/008-010/015-012/020

VI. Geomagnetic Activity Probabilities 26 Sep-28 Sep

A. Middle Latitudes

• Active 15/20/20
• Minor storm 05/10/10
• Major-severe storm 01/01/01

B. High Latitudes

• Active 20/25/25
• Minor storm 10/15/15
• Major-severe storm 01/01/01