Joint USAF/NOAA Report of Solar and Geophysical Activity 17 Aug 2005

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Aug 17 2203 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 229 Issued at 2200Z on 17 Aug 2005

IA. Analysis of Solar Active Regions and Activity from 16/2100Z
to 17/2100Z: Solar activity was very low. Region 797 (S14W23)
continues to slowly decay in area and magnetic complexity. No new
regions were numbered today.

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

IIA. Geophysical Activity Summary 16/2100Z to 17/2100Z:
The geomagnetic field was mostly unsettled to active. Solar wind
speed at ACE has been variable between approximately 600 km/s to 750
km/s due to the continued influence of a coronal hole high speed
stream.

IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be at mostly unsettled levels on 18 August and gradually
diminish to quiet to unsettled conditions by 19 – 20 August.

III. Event Probabilities 18 Aug-20 Aug

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

IV. Penticton 10.7 cm Flux

• Observed 17 Aug 077
• Predicted 18 Aug-20 Aug 075/080/080
• 90 Day Mean 17 Aug 093

V. Geomagnetic A Indices

• Observed Afr/Ap 16 Aug 012/019
• Estimated Afr/Ap 17 Aug 012/016
• Predicted Afr/Ap 18 Aug-20 Aug 010/015-008/008-004/007

VI. Geomagnetic Activity Probabilities 18 Aug-20 Aug

A. Middle Latitudes

• Active 25/20/15
• Minor storm 10/10/05
• Major-severe storm 01/01/01

B. High Latitudes

• Active 35/20/20
• Minor storm 15/10/10
• Major-severe storm 10/01/01