Joint USAF/NOAA Report of Solar and Geophysical Activity 11 Apr 2006

Product: Report of Solar-Geophysical Activity
Issued: 2006 Apr 11 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 101 Issued at 2200Z on 11 Apr 2006

IA. Analysis of Solar Active Regions and Activity from 10/2100Z to 11/2100Z: Solar activity increased to low levels. Region 871 (S08E39) produced the largest flare during the period, a C2/1n event occurring at 11/1839Z. Region 870 (S08E09) produced two C1 flares today, the first occurring at 11/0200Z and the second at 11/0439Z. Regions 872 (S09E74) and 873 (S04E48) were numbered today.

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

IIA. Geophysical Activity Summary 10/2100Z to 11/2100Z: The geomagnetic field was at quiet to unsettled levels. 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 at quiet to unsettled levels on 12 and 13 April. Isolated minor to severe storm conditions are possible on 14 April due to a recurrent coronal hole high speed stream.

III. Event Probabilities 12 Apr-14 Apr

• Class M 05/05/05
• Class X 01/01/01
• Proton 01/01/01
• PCAF green

IV. Penticton 10.7 cm Flux

• Observed 11 Apr 090
• Predicted 12 Apr-14 Apr 090/090/090
• 90 Day Mean 11 Apr 080

V. Geomagnetic A Indices

• Observed Afr/Ap 10 Apr 011/018
• Estimated Afr/Ap 11 Apr 006/006
• Predicted Afr/Ap 12 Apr-14 Apr 005/008-005/010-015/025

VI. Geomagnetic Activity Probabilities 12 Apr-14 Apr A. Middle Latitudes

• Active 15/15/35
• Minor storm 01/01/15
• Major-severe storm 01/01/05

B. High Latitudes

• Active 15/20/50
• Minor storm 05/05/25
• Major-severe storm 01/01/15