Report of Solar-Geophysical Activity

Issued: 2006 Aug 23 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 235 Issued at 2200Z on 23 Aug 2006 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity was very low. Region 905 (S08E47), the only sunspot group on the visible disk, produced isolated B-class flares. This active region exhibited little change this period and maintains a reversed polarity magnetic structure.

IB. Solar Activity Forecast: Solar activity is expected to continue at very low levels. There is a slight chance for a C-class flare from Region 905.

IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z:

The geomagnetic field was quiet to unsettled. Solar wind speed declined from a maximum of near 500 km/s to end the period at 420 km/s. The greater than 2 MeV electron flux at geosynchronous orbit was at high levels.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be quiet to unsettled with isolated active periods.

III. Event Probabilities 24 Aug-26 Aug

Class M 05/05/05

Class X 01/01/01

Proton 01/01/01

PCAF green

IV. Penticton 10.7 cm Flux

Observed 23 Aug 078

Predicted 24 Aug-26 Aug 080/080/080

90 Day Mean 23 Aug 077

V. Geomagnetic A Indices

Observed Afr/Ap 22 Aug 017/017

Estimated Afr/Ap 23 Aug 008/008

Predicted Afr/Ap 24 Aug-26 Aug 008/008-005/008-005/008 VI. Geomagnetic Activity Probabilities 24 Aug-26 Aug A. Middle Latitudes

Active 30/25/25

Minor storm 05/05/05

Major-severe storm 01/01/01

B. High Latitudes

Active 35/30/30

Minor storm 10/10/10

Major-severe storm 05/05/05