Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Oct 2005

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force. Updated 2005 Oct 20 2204 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 293 Issued at 2200Z on 20 Oct 2005

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was very low. No flares were observed during the past 24 hours.

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

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was quiet. The greater than 2 MeV electron flux reached high levels during the past 24 hours.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet on 21 Oct. Unsettled conditions, with a chance for active periods, are expected for 22-23 Oct, due to a favorably positioned coronal hole.

III. Event Probabilities 21 Oct-23 Oct

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

IV. Penticton 10.7 cm Flux

• Observed 20 Oct 077
• Predicted 21 Oct-23 Oct 078/078/078
• 90 Day Mean 20 Oct 088

V. Geomagnetic A Indices

• Observed Afr/Ap 19 Oct 003/007
• Estimated Afr/Ap 20 Oct 005/008
• Predicted Afr/Ap 21 Oct-23 Oct 005/005-010/012-010/012

VI. Geomagnetic Activity Probabilities 21 Oct-23 Oct

A. Middle Latitudes

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

B. High Latitudes

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