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

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

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 298 Issued at 2200Z on 25 Oct 2005

IA. Analysis of Solar Active Regions and Activity from 24/2100Z to 25/2100Z: Solar activity was at very low levels. No sunspots were reported on the visible disk. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at very low levels.

IIA. Geophysical Activity Summary 24/2100Z to 25/2100Z: The geomagnetic field was at quiet to active levels. A solar sector boundary crossing was observed at ACE at 24/2000 UTC. Solar wind speed is elevated at approximately 450 km/s due to a geoeffective coronal hole high speed wind stream.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at quiet to unsettled levels. Isolated active conditions are possible due to the ongoing effects of a coronal hole high speed stream.

III. Event Probabilities 26 Oct-28 Oct

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

IV. Penticton 10.7 cm Flux

• Observed 25 Oct 073
• Predicted 26 Oct-28 Oct 075/075/075
• 90 Day Mean 25 Oct 088

V. Geomagnetic A Indices

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

VI. Geomagnetic Activity Probabilities 26 Oct-28 Oct

A. Middle Latitudes

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

B. High Latitudes

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