Joint USAF/NOAA Report of Solar and Geophysical Activity 21 Aug 2006

Product: Report of Solar-Geophysical Activity
Issued: 2006 Aug 21 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 233 Issued at 2200Z on 21 Aug 2006

IA. Analysis of Solar Active Regions and Activity from 20/2100Z to 21/2100Z: Solar activity was low. Newly numbered Region 905 (S08E72) produced six C-class flares over the past 24 hours, the largest of which was a C3 flare at 21/0226Z. Region 904 (S12W88) produced two C-class flares, including a C4/Sf at 20/2102Z.

IB. Solar Activity Forecast: Solar activity is expected to be low with a slight chance for an isolated M-class flare from Region 905.

IIA. Geophysical Activity Summary 20/2100Z to 21/2100Z: The geomagnetic field was quiet to unsettled with a single active period. 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 to unsettled with isolated active periods on 22 August. Mostly quiet conditions are expected on 23 – 24 August.

III. Event Probabilities 22 Aug-24 Aug

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

IV. Penticton 10.7 cm Flux

• Observed 21 Aug 088
• Predicted 22 Aug-24 Aug 090/085/085
• 90 Day Mean 21 Aug 077

V. Geomagnetic A Indices

• Observed Afr/Ap 20 Aug 014/024
• Estimated Afr/Ap 21 Aug 010/010
• Predicted Afr/Ap 22 Aug-24 Aug 008/008-005/005-005/005

VI. Geomagnetic Activity Probabilities 22 Aug-24 Aug A. Middle Latitudes

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

B. High Latitudes

• Active 30/25/25
• Minor storm 10/10/10
• Major-severe storm 01/01/01