Joint USAF/NOAA Report of Solar and Geophysical Activity 20 Oct 2006

Product: Report of Solar-Geophysical Activity
Issued: 2006 Oct 20 2200 UTC
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 293 Issued at 2200Z on 20 Oct 2006

IA. Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was very low.

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

IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field ranged from quiet to active. Solar wind speed has been increasing steadily over the past 24 hours as a coronal hole high speed stream rotates into a geoeffective position. At time of issue, the solar wind speed was approximately 500 km/s. The greater than 2 MeV electron flux reached high levels today.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be unsettled to active with periods of minor storming on 21 October due to a recurrent coronal hole high speed stream. The geomagnetic field is expected to be quiet to unsettled for 22 and 23 October.

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 071
• Predicted 21 Oct-23 Oct 070/070/070
• 90 Day Mean 20 Oct 077

V. Geomagnetic A Indices

• Observed Afr/Ap 19 Oct 001/002
• Estimated Afr/Ap 20 Oct 015/010
• Predicted Afr/Ap 21 Oct-23 Oct 010/020-008/008-005/005

VI. Geomagnetic Activity Probabilities 21 Oct-23 Oct A. Middle Latitudes

• Active 35/30/20
• Minor storm 15/15/10
• Major-severe storm 05/05/02

B. High Latitudes

• Active 45/40/30
• Minor storm 25/25/20
• Major-severe storm 10/05/05